Science.gov

Sample records for ac induction motor

  1. Fuzzy efficiency optimization of AC induction motors

    NASA Technical Reports Server (NTRS)

    Jani, Yashvant; Sousa, Gilberto; Turner, Wayne; Spiegel, Ron; Chappell, Jeff

    1993-01-01

    This paper describes the early states of work to implement a fuzzy logic controller to optimize the efficiency of AC induction motor/adjustable speed drive (ASD) systems running at less than optimal speed and torque conditions. In this paper, the process by which the membership functions of the controller were tuned is discussed and a controller which operates on frequency as well as voltage is proposed. The membership functions for this dual-variable controller are sketched. Additional topics include an approach for fuzzy logic to motor current control which can be used with vector-controlled drives. Incorporation of a fuzzy controller as an application-specific integrated circuit (ASIC) microchip is planned.

  2. Save power in AC induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J.

    1977-01-01

    Relatively simple and inexpensive circuitry improves power factor and reduces power dissipation in induction motors operating below full load. Electronic control loop conserves energy by reducing voltage applied to lightly loaded motor. Circuit forces motor to run at constant predetermined optimum power factor, regardless of load or line voltage variations. Solid-state switch varies voltage.

  3. Power factor control system for AC induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1977-01-01

    A power factor control system for use with ac induction motors was designed which samples lines voltage and current through the motor and decreases power input to the motor proportional to the detected phase displacement between current and voltage. This system provides, less power to the motor, as it is less loaded.

  4. FUZZY LOGIC CONTROL OF AC INDUCTION MOTORS

    EPA Science Inventory

    The paper discusses the fuzzy logic control (FLC) of electric motors, being investigated under the sponsorship of the U.S. EPA to reduce energy consumption when motors are operated at less than rated speeds and loads. lectric motors use 60% of the electrical energy generated in t...

  5. Offline detection of broken rotor bars in AC induction motors

    NASA Astrophysics Data System (ADS)

    Powers, Craig Stephen

    ABSTRACT. OFFLINE DETECTION OF BROKEN ROTOR BARS IN AC INDUCTION MOTORS. The detection of the broken rotor bar defect in medium- and large-sized AC induction machines is currently one of the most difficult tasks for the motor condition and monitoring industry. If a broken rotor bar defect goes undetected, it can cause a catastrophic failure of an expensive machine. If a broken rotor bar defect is falsely determined, it wastes time and money to physically tear down and inspect the machine only to find an incorrect diagnosis. Previous work in 2009 at Baker/SKF-USA in collaboration with the Korea University has developed a prototype instrument that has been highly successful in correctly detecting the broken rotor bar defect in ACIMs where other methods have failed. Dr. Sang Bin and his students at the Korea University have been using this prototype instrument to help the industry save money in the successful detection of the BRB defect. A review of the current state of motor conditioning and monitoring technology for detecting the broken rotor bar defect in ACIMs shows improved detection of this fault is still relevant. An analysis of previous work in the creation of this prototype instrument leads into the refactoring of the software and hardware into something more deployable, cost effective and commercially viable.

  6. Variable-frequency inverter controls torque, speed, and braking in ac induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J.

    1974-01-01

    Dc to ac inverter provides optimum frequency and voltage to ac induction motor, in response to different motor-load and speed requirements. Inverter varies slip frequency of motor in proportion to required torque. Inverter protects motor from high current surges, controls negative slip to apply braking, and returns energy stored in momentum of load to dc power source.

  7. Motor power control circuit for ac induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1983-01-01

    A motor power control of the type which functions by controlling the power factor wherein one of the parameters of power factor current on time is determined by the on time of a triac through which current is supplied to the motor. By means of a positive feedback circuit, a wider range of control is effected.

  8. Ac hysteresis loop measurement of stator-tooth in induction motor

    SciTech Connect

    Son, D.

    1999-09-01

    The properties of ac hysteresis loop of a stator tooth in a 5 hp induction motor was measured and analyzed. The load increase on the motor decreased magnetic induction, however increase the minor hysteresis loops in the high induction region. This effect caused increase in the core loss. Depending on condition of the motor, the core loss of the stator tooth can be 50% greater than the core loss under sinusoidal magnetic induction waveform.

  9. Power factor control system for ac induction motors

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1981-01-01

    A power control circuit for an induction motor is disclosed in which a servo loop is used to control power input by controlling the power factor of motor operation. The power factor is measured by summing the voltage and current derived square wave signals.

  10. Variable frequency inverter for ac induction motors with torque, speed and braking control

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1975-01-01

    A variable frequency inverter was designed for driving an ac induction motor which varies the frequency and voltage to the motor windings in response to varying torque requirements for the motor so that the applied voltage amplitude and frequency are of optimal value for any motor load and speed requirement. The slip frequency of the motor is caused to vary proportionally to the torque and feedback is provided so that the most efficient operating voltage is applied to the motor. Winding current surge is limited and a controlled negative slip causes motor braking and return of load energy to a dc power source.

  11. EFFICIENCY OPTIMIZATION CONTROL OF AC INDUCTION MOTORS: INITIAL LABORATORY RESULTS

    EPA Science Inventory

    The report discusses the development of a fuzzy logic, energy-optimizing controller to improve the efficiency of motor/drive combinations that operate at varying loads and speeds. his energy optimizer is complemented by a sensorless speed controller that maintains motor shaft rev...

  12. EFFICIENCY OPTIMIZATIN CONTROL OF AC INDUCTION MOTORS: INITIAL LABORATORY RESULTS

    EPA Science Inventory

    The report discusses the development of a fuzzy logic, energy-optimizing controller to improve the efficiency of motor/drive combinations that operate at varying loads and speeds. This energy optimizer is complemented by a sensorless speed controller that maintains motor shaft re...

  13. Sensorless speed estimation of an AC induction motor by using an artificial neural network approach

    NASA Astrophysics Data System (ADS)

    Alkhoraif, Abdulelah Ali

    Sensorless speed detection of an induction motor is an attractive area for researchers to enhance the reliability of the system and to reduce the cost of the components. This paper presents a simple method of estimating a rotational speed by utilizing an artificial neural network (ANN) that would be fed by a set of stator current frequencies that contain some saliency harmonics. This approach allows operators to detect the speed in induction motors such an approach also provides reliability, low cost, and simplicity. First, the proposed method is based on converting the stator current signals to the frequency domain and then applying a tracking algorithm to the stator current spectrum in order to detect frequency peaks. Secondly, the ANN has to be trained by the detected peaks; the training data must be from very precise data to provide an accurate rotor speed. Moreover, the desired output of the training is the speed, which is measured by a tachometer simultaneously with the stator current signal. The databases were collected at many different speeds from two different types of AC induction motors, wound rotor and squirrel cage. They were trained and tested, so when the difference between the desired speed value and the ANN output value reached the wanted accuracy, the system does not need to use the tachometer anymore. Eventually, the experimental results show that in an optimal ANN design, the speed of the wound rotor induction motor was estimated accurately, where the testing average error was 1 RPM. The proposed method has not succeeded to predict the rotor speed of the squirrel cage induction motor precisely, where the smallest testing­average error that was achieved was 5 RPM.

  14. Coupling an induction motor type generator to ac power lines. [making windmill generators compatible with public power lines

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1984-01-01

    A system for coupling an induction motor type generator to an A.C. power line includes an electronic switch means that is controlled by a control system and is regulated to turn on at a relatively late point in each half cycle of its operation. The energizing power supplied by the line to the induction motor type generator is decreased and the net power delivered to the line is increased.

  15. Method and apparatus for pulse width modulation control of an AC induction motor

    DOEpatents

    Geppert, Steven; Slicker, James M.

    1984-01-01

    An inverter is connected between a source of DC power and a three-phase AC induction motor, and a micro-processor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .THETA., where .THETA. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands of electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.

  16. Method and apparatus for pulse width modulation control of an AC induction motor

    NASA Technical Reports Server (NTRS)

    Geppert, Steven (Inventor); Slicker, James M. (Inventor)

    1984-01-01

    An inverter is connected between a source of DC power and a three-phase AC induction motor, and a micro-processor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .THETA., where .THETA. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands of electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a flyback DC-DC converter circuit for recharging the battery.

  17. Implementation of damped-oscillation crane control for existing ac induction motor-driven cranes

    SciTech Connect

    Noakes, M.W.; Kress, R.L.; Appleton, G.T.

    1993-04-01

    The Oak Ridge National Laboratory (ORNL) has implemented damped-oscillation crane control on one of its existing ac induction motor-driven facility overhead cranes. The purpose of this engineering grade test has been to determine feasibility, determine control and interfacing specifications, and establish the capability of newly available ac motor-control hardware. A flux vector inverter drive is used in the initial demonstration to investigate acceptability for swing-free crane control. Motor performance and restrictions are also examined. Control hardware design is based upon the Environmental Restoration and Waste Management (ER&WM) Robotics Technology Development Program (RTDP) standards. This includes the use of the VME bus and Motorola 680X0-based CPU boards for the hardware and UNIX and VxWorks for the software. However, smaller, cheaper, and more simple embedded controller design constraints are also considered in order to make the technology more attractive for general industrial use. Theoretical background, specific implementation, and recommendations are presented in this paper.

  18. Implementation of damped-oscillation crane control for existing ac induction motor-driven cranes

    SciTech Connect

    Noakes, M.W.; Kress, R.L. ); Appleton, G.T. . School of Electrical Engineering)

    1993-01-01

    The Oak Ridge National Laboratory (ORNL) has implemented damped-oscillation crane control on one of its existing ac induction motor-driven facility overhead cranes. The purpose of this engineering grade test has been to determine feasibility, determine control and interfacing specifications, and establish the capability of newly available ac motor-control hardware. A flux vector inverter drive is used in the initial demonstration to investigate acceptability for swing-free crane control. Motor performance and restrictions are also examined. Control hardware design is based upon the Environmental Restoration and Waste Management (ER WM) Robotics Technology Development Program (RTDP) standards. This includes the use of the VME bus and Motorola 680X0-based CPU boards for the hardware and UNIX and VxWorks for the software. However, smaller, cheaper, and more simple embedded controller design constraints are also considered in order to make the technology more attractive for general industrial use. Theoretical background, specific implementation, and recommendations are presented in this paper.

  19. A transputer-based adaptive speed controller for AC induction motor drives with load torque estimation

    SciTech Connect

    Tsai, M.F.; Tzou, Y.Y.

    1997-03-01

    In this paper, the authors design and implement an adaptive speed controller that can estimate load torque for ac induction motor drives employing a transputer-based parallel processing technique. The adaptive speed controller, which precedes the field-oriented control loop, consists of a two-degree-of-freedom controller and a feedforward load-torque compensator. The two-degree-of-freedom controller is designed by a pole-placement technique with polynomial manipulations. Its parameters are adjusted adaptively in terms of estimated model parameters. Estimating the model parameters entails a second-order least-squares estimator with constant trace to avoid estimator windup. The design of the feedforward compensator is based on an estimated load-torque model. Estimating the load torque entails a first-order least-squares estimator with variable forgetting factor and covariance resetting, the purposes of which are to detect any slow or sudden changes of torque disturbance, respectively. The resulting adaptive controller is implemented in parallel by IMS T800-20 transputers. Experimental results demonstrate the robustness of the proposed control method in contending with varying load and torque disturbance.

  20. ac bidirectional motor controller

    NASA Technical Reports Server (NTRS)

    Schreiner, K.

    1988-01-01

    Test data are presented and the design of a high-efficiency motor/generator controller at NASA-Lewis for use with the Space Station power system testbed is described. The bidirectional motor driver is a 20 kHz to variable frequency three-phase ac converter that operates from the high-frequency ac bus being designed for the Space Station. A zero-voltage-switching pulse-density-modulation technique is used in the converter to shape the low-frequency output waveform.

  1. Experimental implementation of a robust damped-oscillation control algorithm on a full-sized, two-degree-of-freedom, AC induction motor-driven crane

    NASA Astrophysics Data System (ADS)

    Kress, R. L.; Jansen, J. F.; Noakes, M. W.

    When suspended payloads are moved with an overhead crane, pendulum like oscillations are naturally introduced. This presents a problem any time a crane is used, especially when expensive and/or delicate objects are moved, when moving in a cluttered and/or hazardous environment, and when objects are to be placed in tight locations. Damped-oscillation control algorithms have been demonstrated over the past several years for laboratory-scale robotic systems on dc motor-driven overhead cranes. Most overhead cranes presently in use in industry are driven by ac induction motors; consequently, Oak Ridge National Laboratory has implemented damped-oscillation crane control on one of its existing facility ac induction motor-driven overhead cranes. The purpose of this test was to determine feasibility, to work out control and interfacing specifications, and to establish the capability of newly available ac motor control hardware with respect to use in damped-oscillation-controlled systems. Flux vector inverter drives are used to investigate their acceptability for damped-oscillation crane control. The purpose of this paper is to describe the experimental implementation of a control algorithm on a full-sized, two-degree-of-freedom, industrial crane; describe the experimental evaluation of the controller including robustness to payload length changes; explain the results of experiments designed to determine the hardware required for implementation of the control algorithms; and to provide a theoretical description of the controller.

  2. Experimental implementation of a robust damped-oscillation control algorithm on a full-sized, two-degree-of-freedom, AC induction motor-driven crane

    SciTech Connect

    Kress, R.L.; Jansen, J.F.; Noakes, M.W.

    1994-05-01

    When suspended payloads are moved with an overhead crane, pendulum like oscillations are naturally introduced. This presents a problem any time a crane is used, especially when expensive and/or delicate objects are moved, when moving in a cluttered an or hazardous environment, and when objects are to be placed in tight locations. Damped-oscillation control algorithms have been demonstrated over the past several years for laboratory-scale robotic systems on dc motor-driven overhead cranes. Most overhead cranes presently in use in industry are driven by ac induction motors; consequently, Oak Ridge National Laboratory has implemented damped-oscillation crane control on one of its existing facility ac induction motor-driven overhead cranes. The purpose of this test was to determine feasibility, to work out control and interfacing specifications, and to establish the capability of newly available ac motor control hardware with respect to use in damped-oscillation-controlled systems. Flux vector inverter drives are used to investigate their acceptability for damped-oscillation crane control. The purpose of this paper is to describe the experimental implementation of a control algorithm on a full-sized, two-degree-of-freedom, industrial crane; describe the experimental evaluation of the controller including robustness to payload length changes; explain the results of experiments designed to determine the hardware required for implementation of the control algorithms; and to provide a theoretical description of the controller.

  3. The induction motor

    NASA Astrophysics Data System (ADS)

    Redinz, José Arnaldo

    2015-09-01

    We obtain analytical expressions for the torques and angular speed of an induction motor with a simple geometry, resembling the geometry of the first induction motor investigated by Arago in 1824. The rotor is a conducting disc rotating between the magnetic poles of two off-axis solenoids, displaced in space by 90^\\circ from each other. We apply our results to discuss a theory for the ubiquitous electromechanical watt-hour meter. For comparison of the theoretical result for the angular speed with measurements, we propose a simple experiment in which an induction motor with an aluminum disc rotor is constructed.

  4. Comparison of a synergetic battery pack drive system to a pulse width modulated AC induction motor drive for an electric vehicle

    SciTech Connect

    Davis, A.; Salameh, Z.M.; Eaves, S.S.

    1999-06-01

    A new battery configuration technique and accompanying control circuitry, termed a Synergetic Battery Pack (SBP), is designed to work with Lithium batteries, and can be used as both an inverter for an electric vehicle AC induction motor drive and as a battery charger. In this paper, the performance of a Synergetic Battery Pack during motor drive operation is compared via computer simulation with a conventional motor drive which uses sinusoidal pulse width modulation (SPWM) to determine its effectiveness as a motor drive. The study showed that the drive efficiency was compatible with the conventional system, and offered a significant advantage in the lower frequency operating ranges. The voltage total harmonic distortion (THD) of the SBP was significantly lower than the PWM drive output, but the current THD was slightly higher due to the shape of the harmonic spectrum. In conclusion, the SBP is an effective alternative to a conventional drive, but the real advantage lies in its battery management capabilities and charger operation.

  5. Induction motor control

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1990-01-01

    Electromechanical actuators developed to date have commonly utilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilizes induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  6. Induction motor control

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1990-01-01

    Electromechanical actuators developed to date have commonly ultilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilized induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high-frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high-frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  7. Induction motor control

    NASA Astrophysics Data System (ADS)

    Hansen, Irving G.

    Electromechanical actuators developed to date have commonly ultilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilized induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high-frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high-frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  8. IMPROVING AC MOTOR EFFICIENCY WITH FUZZY LOGIC ENERGY OPTIMIZER

    EPA Science Inventory

    The paper discusses EPA's research program to develop fuzzy-logic-based energy optimizers for alternating-current (AC) induction motors driven by Adjustable Speed Drives (ASDs). he technical goals of the program are to increase the efficiency of ASD/motor combinations (especially...

  9. Three phase AC motor controller

    DOEpatents

    Vuckovich, Michael; Wright, Maynard K.; Burkett, John P.

    1984-03-20

    A motor controller for a three phase AC motor (10) which is adapted to operate bidirectionally from signals received either from a computer (30) or a manual control (32). The controller is comprised of digital logic circuit means which implement a forward and reverse command signal channel (27, 29) for the application of power through the forward and reverse power switching relays (16, 18, 20, 22). The digital logic elements are cross coupled to prevent activation of both channels simultaneously and each includes a plugging circuit (65, 67) for stopping the motor upon the removal of control signal applied to one of the two channels (27, 29) for a direction of rotation desired. Each plugging circuit (65, 67) includes a one-shot pulse signal generator (88, 102) which outputs a single pulse signal of predetermined pulsewidth which is adapted to inhibit further operation of the application of power in the channel which is being activated and to apply a reversal command signal to the other channel which provides a reversed phase application of power to the motor for a period defined by the pulse-width output of the one-shot signal generator to plug the motor (10) which will then be inoperative until another rotational command signal is applied to either of the two channels.

  10. Introducing AC inductive reactance with a power tool

    NASA Astrophysics Data System (ADS)

    Bryant, Wesley; Baker, Blane

    2016-09-01

    The concept of reactance in AC electrical circuits is often non-intuitive and difficult for students to grasp. In order to address this lack of conceptual understanding, classroom exercises compare the predicted resistance of a power tool, based on electrical specifications, to measured resistance. Once students discover that measured resistance is smaller than expected, they are asked to explain these observations using previously studied principles of magnetic induction. Exercises also introduce the notion of inductive reactance and impedance in AC circuits and, ultimately, determine self-inductance of the motor windings within the power tool.

  11. Segmented rail linear induction motor

    DOEpatents

    Cowan, Jr., Maynard; Marder, Barry M.

    1996-01-01

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces.

  12. Segmented rail linear induction motor

    DOEpatents

    Cowan, M. Jr.; Marder, B.M.

    1996-09-03

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces. 6 figs.

  13. Online Monitoring of Induction Motors

    SciTech Connect

    McJunkin, Timothy R.; Agarwal, Vivek; Lybeck, Nancy Jean

    2016-01-01

    The online monitoring of active components project, under the Advanced Instrumentation, Information, and Control Technologies Pathway of the Light Water Reactor Sustainability Program, researched diagnostic and prognostic models for alternating current induction motors (IM). Idaho National Laboratory (INL) worked with the Electric Power Research Institute (EPRI) to augment and revise the fault signatures previously implemented in the Asset Fault Signature Database of EPRI’s Fleet Wide Prognostic and Health Management (FW PHM) Suite software. Induction Motor diagnostic models were researched using the experimental data collected by Idaho State University. Prognostic models were explored in the set of literature and through a limited experiment with 40HP to seek the Remaining Useful Life Database of the FW PHM Suite.

  14. Power control for ac motor

    NASA Technical Reports Server (NTRS)

    Dabney, R. W. (Inventor)

    1984-01-01

    A motor controller employing a triac through which power is supplied to a motor is described. The open circuit voltage appearing across the triac controls the operation of a timing circuit. This timing circuit triggers on the triac at a time following turn off which varies inversely as a function of the amplitude of the open circuit voltage of the triac.

  15. HTS axial flux induction motor with analytic and FEA modeling

    NASA Astrophysics Data System (ADS)

    Li, S.; Fan, Y.; Fang, J.; Qin, W.; Lv, G.; Li, J. H.

    2013-11-01

    This paper presents a high-temperature superconductor (HTS) axial-flux induction motor, which can output levitation force and torque simultaneously. In order to analyze the character of the force, analytic method and finite element method are adopted to model the motor. To make sure the HTS can carry sufficiently large current and work well, the magnetic field distribution in HTS coil is calculated. An effective method to improve the critical current of HTS coil is presented. Then, AC losses in HTS windings in the motor are estimated and tested.

  16. Operation Method for AC Motor Control during Power Interruption in Direct AC/AC Converter System

    NASA Astrophysics Data System (ADS)

    Shizu, Keiichiro; Azuma, Satoshi

    Direct AC/AC converters have been studied due to their potential use in power converters with no DC-link capacitor, which can contribute to the miniaturization of power converters. However, the absence of a DC-link capacitor makes it difficult to control the AC motor during power interruption. First, this paper proposes a system that realizes AC motor control during power interruption by utilizing a clamp capacitor. In general, direct AC/AC converters have a clamp circuit consisting of a rectifier diode(s) and a clamp capacitor in order to avoid over-voltages. In the proposed system, there is an additional semiconductor switch reverse-parallel to the rectifier diode(s), and the clamp capacitor voltage can be utilized for AC motor control by turning on the additional switch. Second, this paper discusses an operation method for AC motor control and clamp capacitor voltage control during power interruption. In the proposed method “DC-link voltage control”, the kinetic energy in the AC motor is transformed into electrical energy and stored in the clamp capacitor; the clamp capacitor is therefore charged and the capacitor voltage is controlled to remain constant at an instruction value. Third, this paper discusses a switching operation during power interruption. A dead-time is introduced between the operation of turning off all switches on the rectifier side and the operation of turning on the additional switch, which prevents the occurrence of a short circuit between the interrupted power source and the clamp capacitor. Finally, experimental results are presented. During power interruptions, an output current was continuously obtained and the clamp capacitor voltage was maintained to be equal to the instruction value of the capacitor voltage. These results indicate that both AC motor control and capacitor voltage control were successfully achieved by using the proposed system.

  17. System and method for determining stator winding resistance in an AC motor using motor drives

    DOEpatents

    Lu, Bin; Habetler, Thomas G; Zhang, Pinjia

    2013-02-26

    A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

  18. The right {mu}P simplifies using induction motors to propel electric cars

    SciTech Connect

    Baum, J.; Berringer, K.

    1994-03-31

    In electric vehicles (EVs), AC induction motors can provide variable speed at low cost. The most common method for controlling induction motors uses a 3-phase AC voltage-source inverter with sine-wave PWM (pulse width modulation). Because the motor`s speed and acceleration depend on amplitude as well as frequency, the inverter must produce sine waves of variable voltage and frequency. The authors describe how a single microcontroller can provide such control functions while generating PWM waveforms in which the modulation is sinusoidal.

  19. Improved transistorized AC motor controller for battery powered urban electric passenger vehicles

    NASA Technical Reports Server (NTRS)

    Peak, S. C.

    1982-01-01

    An ac motor controller for an induction motor electric vehicle drive system was designed, fabricated, tested, evaluated, and cost analyzed. A vehicle performance analysis was done to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of ac motor and ac controller requirements. The power inverter is a three-phase bridge using power Darlington transistors. The induction motor was optimized for use with an inverter power source. The drive system has a constant torque output to base motor speed and a constant horsepower output to maximum speed. A gear shifting transmission is not required. The ac controller was scaled from the base 20 hp (41 hp peak) at 108 volts dec to an expanded horsepower and battery voltage range. Motor reversal was accomplished by electronic reversal of the inverter phase sequence. The ac controller can also be used as a boost chopper battery charger. The drive system was tested on a dynamometer and results are presented. The current-controlled pulse width modulation control scheme yielded improved motor current waveforms. The ac controller favors a higher system voltage.

  20. Forward and reverse control system for induction motors

    DOEpatents

    Wright, J.T.

    1987-09-15

    A control system for controlling the direction of rotation of a rotor of an induction motor includes an array of five triacs with one of the triacs applying a current of fixed phase to the windings of the rotor and four of the triacs being switchable to apply either hot ac current or return ac current to the stator windings so as to reverse the phase of current in the stator relative to that of the rotor and thereby reverse the direction of rotation of the rotor. Switching current phase in the stator is accomplished by operating the gates of pairs of the triacs so as to connect either hot ac current or return ac current to the input winding of the stator. 1 fig.

  1. Comparison of capabilities of reluctance synchronous motor and induction motor

    NASA Astrophysics Data System (ADS)

    Štumberger, Gorazd; Hadžiselimović, Miralem; Štumberger, Bojan; Miljavec, Damijan; Dolinar, Drago; Zagradišnik, Ivan

    2006-09-01

    This paper compares the capabilities of a reluctance synchronous motor (RSM) with those of an induction motor (IM). An RSM and IM were designed and made, with the same rated power and speed. They differ only in the rotor portion while their stators, housings and cooling systems are identical. The capabilities of both motors in a variable speed drive are evaluated by comparison of the results obtained by magnetically nonlinear models and by measurements.

  2. An Induction Motor Based Wind Turbine Emulator

    NASA Astrophysics Data System (ADS)

    Sokolovs, A.; Grigans, L.; Kamolins, E.; Voitkans, J.

    2014-04-01

    The authors present a small-scale wind turbine emulator based on the AC drive system and discuss the methods for power coefficient calculation. In the work, the experimental set-up consisting of an AC induction motor, a frequency converter, a synchronous permanent magnet generator, a DC-DC boost converter and DC load was simulated and tested using real-life equipment. The experimentally obtained wind turbine power and torque diagrams using the emulator are in a good agreement with the theoretical ones. Šajā rakstā parādīta mazas jaudas vēja turbīnas emulatora izveide ar maiņstrāvas piedziņas sistēmu, kā arī analizētas vairākas turbīnas jaudas koeficienta analītiskās aprēķina metodes. Vēja turbīnas emulatora eksperimentālais stends, kas sastāv no asinhronā elektromotora, frekvenču pārveidotāja, sinhronā pastāvīgo magnētu ģeneratora, līdzstrāvas paaugstinošā pārveidotāja un slodzes, tika pārbaudīts gan simulēšanas vidē, gan uz reālām iekārtām. Eksperimentāli iegūtās vēja turbīnas emulatora jaudas un momenta diagrammas ir salīdzinātas ar teorētiskajām.

  3. Four quadrant control of induction motors

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1991-01-01

    Induction motors are the nation's workhorse, being the motor of choice in most applications due to their simple rugged construction. It has been estimated that 14 to 27 percent of the country's total electricity use could be saved with adjustable speed drives. Until now, induction motors have not been suited well for variable speed or servo-drives, due to the inherent complexity, size, and inefficiency of their variable speed controls. Work at NASA Lewis Research Center on field oriented control of induction motors using pulse population modulation method holds the promise for the desired drive electronics. The system allows for a variable voltage to frequency ratio which enables the user to operate the motor at maximum efficiency, while having independent control of both the speed and torque of an induction motor in all four quadrants of the speed torque map. Multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of machine. The pulse population technique, results to date, and projections for implementation of this existing new motor control technology are discussed.

  4. Improved transistorized ac motor controller for battery powered urban electric passenger vehicles

    SciTech Connect

    Peak, S.C.

    1982-09-01

    The objectives of this program for an improved ac motor controller for battery powered urban electric passenger vehicles were: the design, fabrication, test, evaluation and cost analysis of an engineering model controller for an ac induction motor drive system, the investigation of a power level expansion to a family of horsepower and battery system voltages, and the investigation of the applicability of the ac controller for use as an on-board battery charger and for providing the function of motor reversal. Additional vehicle specifications, e.g., acceleration and pulling out of potholes, were added to the NASA vehicle specifications. Then, a vehicle performance analysis was done to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of ac motor and ac controller requirements. The General Electric ac induction motor used in the drive is optimized to operate as a vehicle traction motor with a pulse width modulated (PWM) inverter as a power source. The motor is nominally rated 20 hp and 41 hp peak. The power inverter design is a three-phase transistorized bridge configuration with feedback diodes. The transistors are a special design General Electric high-power Darlington transistor rated 450 volts and 200 amps. The battery system voltage chosen was 108 volts. The control strategy is a constant torque profile by PWM operation to base speed and a constant horsepower profile by square-wave operation to maximum speed. A gear shifting transmission is not required. An advanced current-controlled PWM technique is used to control the motor voltage. The primary feedback control is a motor angle control, with voltage and torque outer loop controls.

  5. FORTRAN program for induction motor analysis

    NASA Technical Reports Server (NTRS)

    Bollenbacher, G.

    1976-01-01

    A FORTRAN program for induction motor analysis is described. The analysis includes calculations of torque-speed characteristics, efficiency, losses, magnetic flux densities, weights, and various electrical parameters. The program is limited to three-phase Y-connected, squirrel-cage motors. Detailed instructions for using the program are given. The analysis equations are documented, and the sources of the equations are referenced. The appendixes include a FORTRAN symbol list, a complete explanation of input requirements, and a list of error messages.

  6. Bridge Inductance of Induction Motor with Closed Rotor Slots

    NASA Astrophysics Data System (ADS)

    Matsushita, Makoto; Ishibashi, Fuminori; Suzuki, Takao; Noda, Shinichi

    Closed rotor slots are widely employed in low-power squirrel-cage induction motors with die-cast aluminum cage rotors. Die-cast aluminum cages with closed rotor slots can be manufactured commercially. They help reduce flux pulsation in air gaps, attenuate acoustic noises, and achieve high efficiency. However, it is difficult to calculate bridge inductance of a closed rotor slot accurately because the main flux passes through the bridge and iron saturation can be achieved depending upon the bar current. In this study, bridge inductance was investigated by using a search coil and by FEM analysis and conventional equations. The bridge flux density and the bridge linkage flux were measured by using 4P-0.75kW motor with closed rotor slots, and the bridge inductance was calculated as a function of rotor bar current. The bridge inductance was also analyzed by FEM, and the results were analytically checked by using the calculated conventional equations. From these analyses, it is seen that the measured values of the bridge inductance are in good agreement with the values calculated by FEM and conventional methods. It is verified that the bridge inductance shows a trend similar to that of the μ-H curve of the rotor steel sheet.

  7. A.C. motors for high-performance drives: A design-based comparison

    SciTech Connect

    Vagati, A.; Fratta, A.; Franceschini, G.; Rosso, P.M.

    1995-12-31

    Three AC motors are compared, for application in high-performance controlled drives: induction, brushless and synchronous reluctance motors. Their design is optimized, under common design assumptions. Then, the given stall-torques are compared to each other. In addition, the quadrature reactances are compared, as affecting overload and flux-weakening performances. Last, applicative considerations are given, thus defining the most suitable solution for each field.

  8. INSPECTION MEANS FOR INDUCTION MOTORS

    DOEpatents

    Williams, A.W.

    1959-03-10

    an appartus is descripbe for inspcting electric motors and more expecially an appartus for detecting falty end rings inn suqirrel cage inductio motors while the motor is running. In its broua aspects, the mer would around ce of reference tedtor means also itons in the phase ition of the An electronic circuit for conversion of excess-3 binary coded serial decimal numbers to straight binary coded serial decimal numbers is reported. The converter of the invention in its basic form generally coded pulse words of a type having an algebraic sign digit followed serially by a plurality of decimal digits in order of decreasing significance preceding a y algebraic sign digit followed serially by a plurality of decimal digits in order of decreasing significance. A switching martix is coupled to said input circuit and is internally connected to produce serial straight binary coded pulse groups indicative of the excess-3 coded input. A stepping circuit is coupled to the switching matrix and to a synchronous counter having a plurality of x decimal digit and plurality of y decimal digit indicator terminals. The stepping circuit steps the counter in synchornism with the serial binary pulse group output from the switching matrix to successively produce pulses at corresponding ones of the x and y decimal digit indicator terminals. The combinations of straight binary coded pulse groups and corresponding decimal digit indicator signals so produced comprise a basic output suitable for application to a variety of output apparatus.

  9. Prospects for Brushless ac Motors with HTS Rotors

    NASA Astrophysics Data System (ADS)

    McCulloch, M. D.; Jim, K.; Kawai, Y.; Dew-Hughes, D.; Morgan, C.; Goringe, M. J.; Grovenor, C. R. M.

    1997-03-01

    There is a superconducting equivalent for every type of brushless ac motor; permanent magnet, reluctance, hysteresis and induction (squirrel cage) motor. The particular advantage of superconducting versions of these machines is that they are expected to provide much higher power densities than their conventional equivalents. The behaviour of superconducting rotors fabricated in the form of (a) squirrell cages from silver coated with melt-processed Bi-2212, (b) tubes cast centifugally from Bi-2212, and (c) small cylinders of melt-processed and seeded YBCO has been studied in rotating magnetic fields provided by conventional motor coils. Measurements of static torque, and values of dynamic torque deduced from angular velocity and acceleration have been used to characterise the potential performance of these embryonic machines. Two broad types of behaviour have been observed. In the Bi-2212 rotors the torque decreases with increasing rotor speed; this behaviour is believed due to flux creep. By contrast the strong-pinning YBCO rotors maintain a constant torque up to synchronous speed. Mathematical modelling of flux penetration and distribution within the rotors is able to reproduce both types of the observed behaviour. Power densities some 5 to 10 times that of conventional machines are predicted to be achievable in optimised prototype machines.

  10. Motor torque compensation of an induction electric motor by adjusting a slip command during periods of supposed change in motor temperature

    DOEpatents

    Kelledes, William L.; St. John, Don K.

    1992-01-01

    The present invention maintains constant torque in an inverter driven AC induction motor during variations in rotor temperature. It is known that the torque output of a given AC induction motor is dependent upon rotor temperature. At rotor temperatures higher than the nominal operating condition the rotor impedance increases, reducing the rotor current and motor torque. In a similar fashion, the rotor impedance is reduced resulting in increased rotor current and motor torque when the rotor temperature is lower than the nominal operating condition. The present invention monitors the bus current from the DC supply to the inverter and adjusts the slip frequency of the inverter drive to maintain a constant motor torque. This adjustment is based upon whether predetermined conditions implying increased rotor temperature or decreased rotor temperature exist for longer that a predetermined interval of time.

  11. Harmonic Electromagnetic Forces in Induction Motors

    NASA Astrophysics Data System (ADS)

    Ishibashi, Fuminori; Matsushita, Makoto; Noda, Shinichi

    Recently, there has been increasing demand for quiet motors, and the same trend has been observed in the case of induction motors. In induction motors, electromagnetic noise is sometimes the predominant acoustic noise. In small motors, the major cause of vibration and noise is electromagnetic forces resulting from the combination of harmonic fluxes in the air gap. In this study, the spatial distribution of fundamental and harmonic time electromagnetic forces was studied by using search coils, by performing FEM analysis, and by using conventional equations. In a four-pole 2.2kW motor, harmonic electromagnetic forces were measured using 36 search coils on the inner surface of the stator teeth, and the spatial distribution of electromagnetic forces was obtained at each time harmonic frequency. Spatial distribution was also analyzed by FEM, and the results were analytically validated by using conventional equations. On the basis of these analyses, the spatial distribution of electromagnetic forces for various time harmonics was confirmed. These results can be used in the design and development of quiet motors.

  12. The application of Halbach cylinders to brushless ac servo motors

    SciTech Connect

    Atallah, K.; Howe, D.

    1998-07-01

    Halbach cylinders are applied to brushless ac servo motors. It is shown that a sinusoidal back-emf waveform and a low cogging torque can be achieved without recourse to conventional design features such as distributed windings and/or stator/rotor skew. A technique for imparting a multipole Halbach magnetization distribution on an isotropic permanent magnet cylinder is described, and it is shown that the torque capability of a Halbach ac servo motor can be up to 33% higher than conventional brushless permanent magnet ac motors.

  13. Performance Comparison between a Permanent Magnet Synchronous Motor and an Induction Motor as a Traction Motor for High Speed Train

    NASA Astrophysics Data System (ADS)

    Kondo, Minoru; Kawamura, Junya; Terauchi, Nobuo

    Performance tests are carried out to demonstrate the superiority of a permanent magnet synchronous motor to an induction motor as a traction motor for high-speed train. A prototype motor was manufactured by replacing the rotor of a conventional induction motor. The test results show that the permanent magnet motor is lighter, efficient and more silent than the induction motor because of the different rotor structure.

  14. Field oriented control of induction motors

    NASA Technical Reports Server (NTRS)

    Burrows, Linda M.; Zinger, Don S.; Roth, Mary Ellen

    1990-01-01

    Induction motors have always been known for their simple rugged construction, but until lately were not suitable for variable speed or servo drives due to the inherent complexity of the controls. With the advent of field oriented control (FOC), however, the induction motor has become an attractive option for these types of drive systems. An FOC system which utilizes the pulse population modulation method to synthesize the motor drive frequencies is examined. This system allows for a variable voltage to frequency ratio and enables the user to have independent control of both the speed and torque of an induction motor. A second generation of the control boards were developed and tested with the next point of focus being the minimization of the size and complexity of these controls. Many options were considered with the best approach being the use of a digital signal processor (DSP) due to its inherent ability to quickly evaluate control algorithms. The present test results of the system and the status of the optimization process using a DSP are discussed.

  15. Induction generator-induction motor wind-powered pumping system

    SciTech Connect

    Miranda, M.S.; Lyra, R.O.C.; Silva, S.R.

    1997-12-31

    The energy storage matter plays an important role in wind-electric conversion systems for isolated applications. Having that in mind, two different approaches can be basically considered: either the immediate conversion of the generated electric energy, as in a water pumping system or electric energy storage for later use, as in a battery charging system. Due to some features such as no need of an external reactive power source and, sometimes, a gearbox, permanent-magnet synchronous generators have been broadly used in low rated power isolated systems. Despite that, system performance can be affected when the generator is feeding an inductive load (e.g., an induction motor) under variable-speed-variable-frequency operational conditions. Since there is no effective flux control, motor overload may occur at high wind speeds. Thus, good system performance can be obtained through additional control devices which may increase system cost. Although being rugged and cheap, induction machines always work as a reactive power drain; therefore, they demand an external reactive power source. Considering that, reactive static compensators appear as an attractive alternative to the cost x performance problem. In addition to that, different control strategies can be used so that system performance can be improved.

  16. Sensorless operation of surface mount permanent magnet AC (PMAC) motors

    SciTech Connect

    Toliyat, H.A.; Rahman, K.M.; Shet, D.S.

    1999-12-01

    A sensorless field oriented control scheme for surface mount permanent magnet ac (PMAC) motor with split phase stator windings is presented. This motor is obtained by splitting the phase windings of a conventional three phase motor. The six-phase motor, however is run as a three-phase motor by connecting the split phase stator windings in series, while the taps are made available for voltage measurements. By measuring the terminal voltages and the line currents, absolute position of the permanent magnet ac motor driven by a current regulated PWM inverter with a hysteresis controller is estimated. The estimated position information is independent of the stator resistance, thus this scheme is even applicable at low speeds. Results are presented to show the effectiveness of the new controller, and it is also shown that the position error is negligible.

  17. Load Characteristics of Induction Motor Manufactured by Soft Magnetic Composite

    NASA Astrophysics Data System (ADS)

    Fukuda, Tomohiro; Sasaki, Yutaka; Morimoto, Masayuki

    The load characteristics of induction motor manufactured by soft magnetic composite (SMC) are presented. We manufactured three kinds of induction motors experimentally. One is a conventional laminated iron core motor. The others are SMC motors. One of the SMC motor uses SMC only for stator, while the other SMC motor uses SMC for stator and rotor. The experimental comparisons of load characteristics and loss analysis are shown. As a result, the difference between the efficiency of the SMC motor and the conventional laminated motor is 4.6%, in spite of the permeability of SMC being 20% lower than the conventional electromagnetic steel.

  18. Sequential control by speed drive for ac motor

    NASA Astrophysics Data System (ADS)

    Barsoum, Nader

    2012-11-01

    The speed drive for ac motor is widely used in the industrial field to allow direct control for the speed and torque without any feedback from the motor shaft. By using the ABB ACS800 speed drive unit, the speed and torque can be controlled using sequential control method. Sequential control is one of the application control method provided in the ABB ACS800 Drive, where a set of events or action performed in a particular order one after the other to control the speed and torque of the ac motor. It was claimed that sequential control method is using the preset seven constant speeds being provided in ABB ACS800 drive to control the speed and torque in a continuous and sequential manner. The characteristics and features of controlling the speed and torque using sequential control method can be investigated by observing the graphs and curves plotted which are obtained from the practical result. Sequential control can run either in the Direct Torque Control (DTC) or Scalar motor control mode. By using sequential control method, the ABB ACS800 drive can be programmed to run the motor automatically according to the time setting of the seven preset constant speeds. Besides, the intention of this project is to generate a new form of the experimental set up.

  19. Progress on advanced dc and ac induction drives for electric vehicles

    NASA Technical Reports Server (NTRS)

    Schwartz, H. J.

    1982-01-01

    Progress is reported in the development of complete electric vehicle propulsion systems, and the results of tests on the Road Load Simulator of two such systems representative of advanced dc and ac drive technology are presented. One is the system used in the DOE's ETV-1 integrated test vehicle which consists of a shunt wound dc traction motor under microprocessor control using a transistorized controller. The motor drives the vehicle through a fixed ratio transmission. The second system uses an ac induction motor controlled by transistorized pulse width modulated inverter which drives through a two speed automatically shifted transmission. The inverter and transmission both operate under the control of a microprocessor. The characteristics of these systems are also compared with the propulsion system technology available in vehicles being manufactured at the inception of the DOE program and with an advanced, highly integrated propulsion system upon which technology development was recently initiated.

  20. Improved SCR ac Motor Controller for Battery Powered Urban Electric Vehicles

    NASA Technical Reports Server (NTRS)

    Latos, T. S.

    1982-01-01

    An improved ac motor controller, which when coupled to a standard ac induction motor and a dc propulsion battery would provide a complete electric vehicle power train with the exception of the mechanical transmission and drive wheels was designed. In such a system, the motor controller converts the dc electrical power available at the battery terminals to ac electrical power for the induction motor in response to the drivers commands. The performance requirements of a hypothetical electric vehicle with an upper weight bound of 1590 kg (3500 lb) were used to determine the power rating of the controller. Vehicle acceleration capability, top speed, and gradeability requisites were contained in the Society of Automotive Engineers (SAE) Schedule 227a(d) driving cycle. The important capabilities contained in this driving cycle are a vehicle acceleration requirement of 0 to 72.4 kmph (0 to 45 mph) in 28 seconds a top speed of 88.5 kmph (55 mph), and the ability to negotiate a 10% grade at 48 kmph (30 mph). A 10% grade is defined as one foot of vertical rise per 10 feet of horizontal distance.

  1. Critical field measurements in superconductors using ac inductive techniques

    NASA Astrophysics Data System (ADS)

    Campbell, S. A.; Ketterson, J. B.; Crabtree, G. W.

    1983-09-01

    The ac in-phase and out-of-phase response of type II superconductors is discussed in terms of dc magnetization curves. Hysteresis in the dc magnetization is shown to lead to a dependence of the ac response on the rate at which an external field is swept. This effect allows both Hc1 and Hc2 to be measured by ac techniques. A relatively simple mutual inductance bridge for making such measurements is described in the text, and factors affecting bridge sensitivity are discussed in the Appendix. Data for the magnetic superconductor ErRh4B4 obtained using this bridge are reported.

  2. Phase-sensitive detection of both inductive and non-inductive ac voltages in ferromagnetic resonance

    NASA Astrophysics Data System (ADS)

    Weiler, Mathias; Shaw, Justin M.; Nembach, Hans T.; Schoen, Martin A.; Boone, Carl T.; Silva, Thomas J.

    2014-03-01

    Spin pumping causes significant damping in ultrathin ferromagnetic/normal metal (NM) multilayers via spin-current generation of both dc and ac character in the NM system. While the nonlinear dc component has been investigated in detail by utilization of the inverse spin Hall effect (iSHE) in NMs, much less is known about the linear ac component that is presumably much larger in the small-excitation limit. We measured generated ac voltages in a wide variety of Permalloy/NM multilayers via vector-network-analyzer ferromagnetic resonance. We employ a custom, impedance-matched, broadband microwave coupler that features a ferromagnetic thin film reference resonator to accurately compare ac voltage amplitudes and phases between varieties of multilayers. By use of the fact that inductive and ac iSHE signals are phase-shifted by π/2, we find that inductive signals are major contributors in all investigated samples. It is only by comparison of the phase and amplitude of the recorded ac voltages between multiple samples that we can extract the non-inductive contributions due to spin-currents. Voltages due to the ac iSHE in Permalloy(10nm)/platinum(5nm) bilayers are weaker than inductive signals, in agreement with calculations based upon recent theoretical predictions. M.W. acknowledges financial support by the German Academic Exchange service (DAAD).

  3. Equivalence Between Squirrel Cage and Sheet Rotor Induction Motor

    NASA Astrophysics Data System (ADS)

    Dwivedi, Ankita; Singh, S. K.; Srivastava, R. K.

    2015-03-01

    Due to topological changes in dual stator induction motor and high cost of its fabrication, it is convenient to replace the squirrel cage rotor with a composite sheet rotor. For an experimental machine, the inner and outer stator stampings are normally available whereas the procurement of rotor stampings is quite cumbersome and is not always cost effective. In this paper, the equivalence between sheet/solid rotor induction motor and squirrel cage induction motor has been investigated using layer theory of electrical machines, so as to enable one to utilize sheet/solid rotor in dual port experimental machines.

  4. Equivalence Between Squirrel Cage and Sheet Rotor Induction Motor

    NASA Astrophysics Data System (ADS)

    Dwivedi, Ankita; Singh, S. K.; Srivastava, R. K.

    2016-06-01

    Due to topological changes in dual stator induction motor and high cost of its fabrication, it is convenient to replace the squirrel cage rotor with a composite sheet rotor. For an experimental machine, the inner and outer stator stampings are normally available whereas the procurement of rotor stampings is quite cumbersome and is not always cost effective. In this paper, the equivalence between sheet/solid rotor induction motor and squirrel cage induction motor has been investigated using layer theory of electrical machines, so as to enable one to utilize sheet/solid rotor in dual port experimental machines.

  5. Predictive Direct Torque Control for Induction Motor Drive

    NASA Astrophysics Data System (ADS)

    Benzaioua, A.; Ouhrouche, M.; Merabet, A.

    2008-06-01

    A predictive control combined with the direct torque control (DTC) to induction motor drive is presented. A new switching strategy is used in DTC, where the constant switching frequency is taken constant, and the speed tracking is done by a predictive controller. The scheme control is applied to induction motor drive in order to perform the dynamic responses of electromagnetic torque, stator flux and speed. A comparison between the PI controller and predictive controller for speed tracking is done. Results of simulation show that the performance of the proposed control scheme for induction motor drive is accurately achieved.

  6. A combined lift and propulsion system of a steel plate by transverse flux linear induction motors

    SciTech Connect

    Hayashiya, H.; Ohsaki, H.; Masada, E.

    1999-09-01

    To realize a non-contacting conveyance of a steel plate, a combined lift and propulsion system of a steel plate by transverse flux linear induction motors (LIMs) is proposed. By introducing the DC biased AC feeding to the LIM< a steel plate is supported stably and efficiently. In this paper, after showing the advantages of the system, the magnetic levitation experiments are carried out to investigate the feasibility of the system.

  7. Influence analysis of structural parameters and operating parameters on electromagnetic properties of HTS linear induction motor

    NASA Astrophysics Data System (ADS)

    Fang, J.; Sheng, L.; Li, D.; Zhao, J.; Li, Sh.; Qin, W.; Fan, Y.; Zheng, Q. L.; Zhang, W.

    A novel High Temperature Superconductor Linear Induction Motor (HTS LIM) is researched in this paper. Since the critical current and the electromagnetic force of the motor are determined mainly by the primary slot leakage flux, the main magnetic flux and eddy current respectively, in order to research the influence of structural parameters and operating parameters on electromagnetic properties of HTS LIM, the motor was analyzed by 2D transient Finite Element Method (FEM). The properties of the motor, such as the maximum slot leakage flux density, motor thrust, motor vertical force and critical current are analyzed with different structural parameters and operating parameters. In addition, an experimental investigation was carried out on prototype HTS motor. Electrical parameters were deduced from these tests and also compared with the analysis results from FEM. AC losses of one HTS coil in the motor were measured and AC losses of all HTS coils in HTS LIM were estimated. The results in this paper could provide reference for the design and research on the HTS LIM.

  8. Designing LC filters for AC-motor drives

    SciTech Connect

    Gath, P.A.; Lucas, M.

    1995-12-31

    This paper presents practical design guidelines for designing LC filters for AC-motor drive applications. A DC choke and an electrolytic capacitor bank on the DC bus filter the voltage and the current ripples and improve the input power factor. Capacitor and choke values are derived to optimize overall filter performance. Costs associated with the respective component values can then be obtained to analyze cost trade-offs between selected values. Helpful hints are also given.

  9. AC motor controller with 180 degree conductive switches

    NASA Technical Reports Server (NTRS)

    Oximberg, Carol A. (Inventor)

    1995-01-01

    An ac motor controller is operated by a modified time-switching scheme where the switches of the inverter are on for electrical-phase-and-rotation intervals of 180.degree. as opposed to the conventional 120.degree.. The motor is provided with three-phase drive windings, a power inverter for power supplied from a dc power source consisting of six switches, and a motor controller which controls the current controlled switches in voltage-fed mode. During full power, each switch is gated continuously for three successive intervals of 60.degree. and modulated for only one of said intervals. Thus, during each 60.degree. interval, the two switches with like signs are on continuously and the switch with the opposite sign is modulated.

  10. Control system for an induction motor with energy recovery

    NASA Technical Reports Server (NTRS)

    Nola, F. J. (Inventor)

    1983-01-01

    A control circuit for an induction motor powered system is disclosed in which a power factor controlled servo loop is used to control, via the phase angle of firing of a triac, the power input to the motor, as a function of load placed on the motor by machinery of the powered system. Then, upon application of torque by this machinery to the motor, which tends to overspeed the motor, the firing angle of the triac is automatically set to a fixed, and relatively short, firing angle.

  11. Performance Analysis of Saturated Induction Motors by Virtual Tests

    ERIC Educational Resources Information Center

    Ojaghi, M.; Faiz, J.; Kazemi, M.; Rezaei, M.

    2012-01-01

    Many undergraduate-level electrical machines textbooks give detailed treatments of the performance of induction motors. Students can deepen this understanding of motor performance by performing the appropriate practical work in laboratories or in simulation using proper software packages. This paper considers various common and less-common tests…

  12. Soft Computing Application in Fault Detection of Induction Motor

    SciTech Connect

    Konar, P.; Puhan, P. S.; Chattopadhyay, P. Dr.

    2010-10-26

    The paper investigates the effectiveness of different patter classifier like Feed Forward Back Propagation (FFBPN), Radial Basis Function (RBF) and Support Vector Machine (SVM) for detection of bearing faults in Induction Motor. The steady state motor current with Park's Transformation has been used for discrimination of inner race and outer race bearing defects. The RBF neural network shows very encouraging results for multi-class classification problems and is hoped to set up a base for incipient fault detection of induction motor. SVM is also found to be a very good fault classifier which is highly competitive with RBF.

  13. Unstable force analysis for induction motor eccentricity

    NASA Astrophysics Data System (ADS)

    Han, Xu; Palazzolo, Alan

    2016-05-01

    The increasing popularity of motors in machinery trains has led to an intensified interest in the forces they produce that may influence machinery vibration. Motor design typically assumes a uniform air gap, however in practice all motors operate with the rotor slightly displaced from the motor centerline in what is referred to as an eccentric position. Rotor center eccentricity can cause a radially unbalanced magnetic field when the motor is operating. This will results in both a radial force pulling the motor further away from the center, and a tangential force which can induce a vibration stability problem. In this paper, a magnetic equivalent circuit MEC modeling method is proposed to calculate both the radial and tangential motor eccentric force. The treatment of tangential force determination is rarely addressed, but it is very important for rotordynamic vibration stability evaluation. The proposed model is also coupled with the motor electric circuit model to provide capability for transient vibration simulations. FEM is used to verify the MEC model. A parametric study is performed on the motor radial and tangential eccentric forces. Also a Jeffcott rotor model is used to study the influence of the motor eccentric force on mechanical vibration stability and nonlinear behavior. Furthermore, a stability criteria for the bearing damping is provided. The motor radial and tangential eccentric forces are both curved fitted to include their nonlinearity in time domain transient simulation for both a Jeffcott rotor model and a geared machinery train with coupled torsional-lateral motion. Nonlinear motions are observed, including limit cycles and bifurcation induced vibration amplitude jumps.

  14. Fuzzy Logic Controlled Solar Module for Driving Three- Phase Induction Motor

    NASA Astrophysics Data System (ADS)

    Afiqah Zainal, Nurul; Sooi Tat, Chan; Ajisman

    2016-02-01

    Renewable energy produced by solar module gives advantages for generated three- phase induction motor in remote area. But, solar module's ou tput is uncertain and complex. Fuzzy logic controller is one of controllers that can handle non-linear system and maximum power of solar module. Fuzzy logic controller used for Maximum Power Point Tracking (MPPT) technique to control Pulse-Width Modulation (PWM) for switching power electronics circuit. DC-DC boost converter used to boost up photovoltaic voltage to desired output and supply voltage source inverter which controlled by three-phase PWM generated by microcontroller. IGBT switched Voltage source inverter (VSI) produced alternating current (AC) voltage from direct current (DC) source to control speed of three-phase induction motor from boost converter output. Results showed that, the output power of solar module is optimized and controlled by using fuzzy logic controller. Besides that, the three-phase induction motor can be drive and control using VSI switching by the PWM signal generated by the fuzzy logic controller. This concluded that the non-linear system can be controlled and used in driving three-phase induction motor.

  15. Transistorized PWM inverter-induction motor drive system

    NASA Technical Reports Server (NTRS)

    Peak, S. C.; Plunkett, A. B.

    1982-01-01

    This paper describes the development of a transistorized PWM inverter-induction motor traction drive system. A vehicle performance analysis was performed to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of inverter and motor specifications. The inverter was a transistorized three-phase bridge using General Electric power Darlington transistors. The description of the design and development of this inverter is the principal object of this paper. The high-speed induction motor is a design which is optimized for use with an inverter power source. The primary feedback control is a torque angle control with voltage and torque outer loop controls. A current-controlled PWM technique is used to control the motor voltage. The drive has a constant torque output with PWM operation to base motor speed and a constant horsepower output with square wave operation to maximum speed. The drive system was dynamometer tested and the results are presented.

  16. Fast recovery, high voltage silicon diodes for AC motor controllers

    NASA Technical Reports Server (NTRS)

    Balodis, V.; Berman, A. H.; Gaugh, C.

    1982-01-01

    The fabrication and characterization of a high voltage, high current, fast recovery silicon diode for use in AC motor controllers, originally developed for NASA for use in avionics power supplies, is presented. The diode utilizes a positive bevel PIN mesa structure with glass passivation and has the following characteristics: peak inverse voltage - 1200 volts, forward voltage at 50 amperes - 1.5 volts, reverse recovery time of 200 nanoseconds. Characterization data for the diode, included in a table, show agreement with design concepts developed for power diodes. Circuit diagrams of the diode are also given.

  17. Analytical and experimental study of high phase order induction motors

    NASA Astrophysics Data System (ADS)

    Klingshirn, Eugene A.

    1989-08-01

    Induction motors having more than three phases were investigated to determine their suitability for electric vehicle applications. The objective was to have a motor with a current rating lower than that of a three-phase motor. The name chosen for these is high phase order (HPO) motors. Motors having six phases and nine phases were given the most attention. It was found that HPO motors are quite suitable for electric vehicles, and for many other applications as well. They have characteristics which are as good as or better than three-phase motors for practically all applications where polyphase induction motors are appropriate. Some of the analysis methods are presented, and several of the equivalent circuits which facilitate the determination of harmonic currents and losses, or currents with unbalanced sources, are included. The sometimes large stator currents due to harmonics in the source voltages are pointed out. Filters which can limit these currents were developed. An analysis and description of these filters is included. Experimental results which confirm and illustrate much of the theory are also included. These include locked rotor test results and full-load performance with an open phase. Also shown are oscillograms which display the reduction in harmonic currents when a filter is used with the experimental motor supplied by a non-sinusoidal source.

  18. Analytical and experimental study of high phase order induction motors

    NASA Technical Reports Server (NTRS)

    Klingshirn, Eugene A.

    1989-01-01

    Induction motors having more than three phases were investigated to determine their suitability for electric vehicle applications. The objective was to have a motor with a current rating lower than that of a three-phase motor. The name chosen for these is high phase order (HPO) motors. Motors having six phases and nine phases were given the most attention. It was found that HPO motors are quite suitable for electric vehicles, and for many other applications as well. They have characteristics which are as good as or better than three-phase motors for practically all applications where polyphase induction motors are appropriate. Some of the analysis methods are presented, and several of the equivalent circuits which facilitate the determination of harmonic currents and losses, or currents with unbalanced sources, are included. The sometimes large stator currents due to harmonics in the source voltages are pointed out. Filters which can limit these currents were developed. An analysis and description of these filters is included. Experimental results which confirm and illustrate much of the theory are also included. These include locked rotor test results and full-load performance with an open phase. Also shown are oscillograms which display the reduction in harmonic currents when a filter is used with the experimental motor supplied by a non-sinusoidal source.

  19. Scalar control on speed drive for ac motor

    NASA Astrophysics Data System (ADS)

    Barsoum, Nader

    2012-11-01

    This paper aims to investigate the performance of ABB ACS800 variable speed drive operating under Scalar Control mode, and eventually develop a set of experimental procedures for undergraduate laboratory purposes. Scalar Control is the most widespread form of ac drive, for its low cost and simplicity especially implemented in the open loop mode. Scalar control is achieved by controlling the stator voltage and frequency, thus maintaining the motor's air-gap flux at a constant value. To illustrate the control method, the ac drive is configured according to the wiring diagram in the firmware manual that the drive control location can be both local and external. The drive is selected to operate under Factory application macro, whereby either ordinary speed control applications or constant speeds applications may be used. Under ordinary speed control, frequency reference signals are provided to the drive through the analogue input AI1. The drive will operate at the given frequency reference value throughout the operation regardless of any changes in the load. The torque speed curve moves along the speed axis with no changes to the shape as the supply frequencies changes. On the other hand, the drive allows three preset constant speed through digital inputs DI5 and DI6. The drive operate at a constant speed value over a time period, and only switch from one constant speed to another constant speed by triggering the two input switches. Scalar control is most suitable for applications not required high precision, such as blowers, fans and pumps.

  20. Fault tolerant vector control of induction motor drive

    NASA Astrophysics Data System (ADS)

    Odnokopylov, G.; Bragin, A.

    2014-10-01

    For electric composed of technical objects hazardous industries, such as nuclear, military, chemical, etc. an urgent task is to increase their resiliency and survivability. The construction principle of vector control system fault-tolerant asynchronous electric. Displaying recovery efficiency three-phase induction motor drive in emergency mode using two-phase vector control system. The process of formation of a simulation model of the asynchronous electric unbalance in emergency mode. When modeling used coordinate transformation, providing emergency operation electric unbalance work. The results of modeling transient phase loss motor stator. During a power failure phase induction motor cannot save circular rotating field in the air gap of the motor and ensure the restoration of its efficiency at rated torque and speed.

  1. System and method for determining stator winding resistance in an AC motor

    DOEpatents

    Lu, Bin; Habetler, Thomas G.; Zhang, Pinjia; Theisen, Peter J.

    2011-05-31

    A system and method for determining stator winding resistance in an AC motor is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor. The circuit includes at least one contactor and at least one switch to control current flow and terminal voltages in the AC motor. The system also includes a controller connected to the circuit and configured to modify a switching time of the at least one switch to create a DC component in an output of the system corresponding to an input to the AC motor and determine a stator winding resistance of the AC motor based on the injected DC component of the voltage and current.

  2. Improved magnetic field analysis of induction motor models

    SciTech Connect

    Enokizono, Masato; Sadanaga, Yuichiro

    1998-09-01

    This paper presents an improved magnetic field analysis for induction motor models. In the analysis with the conventional numerical modeling of magnetic materials, the vector relations between the flux density and the field intensity under a rotating field cannot be expressed exactly. In this paper, the authors derived the tensor magnetic reluctivity from the data measured with two-dimensional measurement method. This expression is applied to analyze a three-phase induction motor model core. The examples show that the calculated results obtained by the new method are different from those of the conventional modeling.

  3. Bearing Fault Detection in Induction Motor-Gearbox Drivetrain

    NASA Astrophysics Data System (ADS)

    Cibulka, Jaroslav; Ebbesen, Morten K.; Robbersmyr, Kjell G.

    2012-05-01

    The main contribution in the hereby presented paper is to investigate the fault detection capability of a motor current signature analysis by expanding its scope to include the gearbox, and not only the induction motor. Detecting bearing faults outside the induction motor through the stator current analysis represents an interesting alternative to traditional vibration analysis. Bearing faults cause changes in the stator current spectrum that can be used for fault diagnosis purposes. A time-domain simulation of the drivetrain model is developed. The drivetrain system consists of a loaded single stage gearbox driven by a line-fed induction motor. Three typical bearing faults in the gearbox are addressed, i.e. defects in the outer raceway, the inner raceway, and the rolling element. The interaction with the fault is modelled by means of kinematical and mechanical relations. The fault region is modelled in order to achieve gradual loss and gain of contact. A bearing fault generates an additional torque component that varies at the specific bearing defect frequency. The presented dynamic electromagnetic dq-model of an induction motor is adjusted for diagnostic purpose and considers such torque variations. The bearing fault is detected as a phase modulation of the stator current sine wave at the expected bearing defect frequency.

  4. Transient effects in application of PWM inverters to induction motors

    SciTech Connect

    Persson, E. )

    1992-10-01

    Standard squirrel cage induction (SCI) motors are subjected to nonsinusoidal waveshapes when supplied form adjustable-frequency inverters. In addition to causing increased heating, these wave patterns can be destructive to the insulation. In particular, pulse width modulated (PWM) inverter output amplitudes and rise times are investigated. Motor insulation capabilities are discussed. In this paper, voltage reflections are simulated for various cable lengths and rise times and are presented graphically. Simulations confirm potential problems with long cables and short rise times.

  5. Induction motor inter turn fault detection using infrared thermographic analysis

    NASA Astrophysics Data System (ADS)

    Singh, Gurmeet; Anil Kumar, T. Ch.; Naikan, V. N. A.

    2016-07-01

    Induction motors are the most commonly used prime movers in industries. These are subjected to various environmental, thermal and load stresses that ultimately reduces the motor efficiency and later leads to failure. Inter turn fault is the second most commonly observed faults in the motors and is considered the most severe. It can lead to the failure of complete phase and can even cause accidents, if left undetected or untreated. This paper proposes an online and non invasive technique that uses infrared thermography, in order to detect the presence of inter turn fault in induction motor drive. Two methods have been proposed that detect the fault and estimate its severity. One method uses transient thermal monitoring during the start of motor and other applies pseudo coloring technique on infrared image of the motor, after it reaches a thermal steady state. The designed template for pseudo-coloring is in acquiescence with the InterNational Electrical Testing Association (NETA) thermographic standard. An index is proposed to assess the severity of the fault present in the motor.

  6. Field-Oriented Control Of Induction Motors

    NASA Technical Reports Server (NTRS)

    Burrows, Linda M.; Roth, Mary Ellen; Zinger, Don S.

    1993-01-01

    Field-oriented control system provides for feedback control of torque or speed or both. Developed for use with commercial three-phase, 400-Hz, 208-V, 5-hp motor. Systems include resonant power supply operating at 20 kHz. Pulse-population-modulation subsystem selects individual pulses of 20-kHz single-phase waveform as needed to synthesize three waveforms of appropriate lower frequency applied to three phase windings of motor. Electric actuation systems using technology currently being built to peak powers of 70 kW. Amplitude of voltage of effective machine-frequency waveform determined by momentary frequency of pulses, while machine frequency determined by rate of repetition of overall temporal pattern of pulses. System enables independent control of both voltage and frequency.

  7. Close up of backup exciter showing induction motor at left ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Close up of backup exciter showing induction motor at left and direct current generator at right. View to west - Mystic Lake Hydroelectric Facility, Powerhouse, Along West Rosebud Creek, 1 3/4 miles northeast of Mystic Lake Dam, Fishtail, Stillwater County, MT

  8. A novel induction motor starting method using superconduction

    NASA Astrophysics Data System (ADS)

    Silva, F. B. B.; Orlando, M. T. D.; Fardin, J. F.; Simonetti, D. S.; Baldan, C. A.

    2014-12-01

    In this paper, an alternative method for starting up induction motors is proposed, taking into account experimental measurements. The new starting current limitation method is based on using a high-temperature superconductor. A prototype of the superconducting starting current limiter was constructed with a commercially available second-generation high-temperature superconductor YBCO tape, and this was tested with a 55-kW industrial induction motor in a 440-V/60-Hz three-phase power grid. Performance evaluations of the superconducting limiter method (applied to startup of the induction motor) were performed and were compared with a direct-on-line starter and an electronic soft starter. In addition, a computational model was developed and used for electromagnetic torque analysis of the system. As significant characteristics, our method offers the ability to limit the starting current of the induction motor with greater electromagnetic torque, reduced current waveform distortion and therefore lower harmonic pollution during startup when compared to the soft starter method.

  9. Demonstration of Lenz's Law with an Induction Motor

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2005-01-01

    The interaction of a conductor with a time-dependent magnetic field is an important topic of electromagnetic theory. A computerized classroom demonstration shows how the eddy currents induced in the rotor of an induction motor cause its rotation or braking. Both phenomena are directly related to Lenz's law.

  10. Supply-pollution (SP) loss in induction motor

    SciTech Connect

    Hsu, J.S.

    1995-07-01

    Power supply in the field is often noticeably polluted with various degrees of harmonics content and unbalanced voltages. In order to assess the energy loss caused by the supply pollution in the widely used induction motors, a method based on the air-gap torque power is discussed.

  11. Constant slip control of induction motor at light load

    SciTech Connect

    Feng Xiaogang; Chen Boshi

    1996-12-31

    The most widely used AC motor drives adopt Rated Flux Control (RFC) method. However, at light load condition, RFC causes excessive iron loss, thus the conversion efficiency of the drive system impaired. This paper introduces a new control approach--Constant Slip Control (CSC), which minimize the stator current at light load, so that the iron loss and reactive power consumption of the motor are decreased. Simulation results compare the power consumption of CSC with that of RFC in order to validate the theoretical development. In the last part, realization of CSC is discussed.

  12. A simplified scheme for induction motor condition monitoring

    NASA Astrophysics Data System (ADS)

    Rodríguez, Pedro Vicente Jover; Negrea, Marian; Arkkio, Antero

    2008-07-01

    This work proposes a general scheme to detect induction motor fault by monitoring the motor current. The scheme is based on signal processing (predictive filters) and soft computing technique (fuzzy logic). The predictive filter is used in order to separate the fundamental component from the harmonic components. Fuzzy logic is used to identify the motor state. Finite element method (FEM) is utilised to generate virtual data that allows to test the proposed technique and foresee the change in the current under different motor conditions. A simple and reliable method for the detection of stator winding failures based on the phase current amplitudes is implemented and tested. The layout has been proved in MATLAB/SIMULINK, with both data from FEM motor simulation program and real measurements. The proposed method has the ability to work with variable speed drives and avoids the detailed spectral analysis of the motor current. This work shows the feasibility of spotting broken rotor bars, eccentricities and inter-turn short-circuit by monitoring the motor currents.

  13. Quantitative analysis of noninvasive diagnostic procedures for induction motor drives

    NASA Astrophysics Data System (ADS)

    Eltabach, Mario; Antoni, Jerome; Najjar, Micheline

    2007-10-01

    This paper reports quantitative analyses of spectral fault components in five noninvasive diagnostic procedures that use input electric signals to detect different types of abnormalities in induction motors. Besides the traditional one phase current spectrum analysis "SC", the diagnostic procedures based on spectrum analysis of the instantaneous partial powers " P ab", " P cb", total power " P abc", and the current space vector modulus " csvm" are considered. The aim of this comparison study is to improve the diagnosis tools for detection of electromechanical faults in electrical machines by using the best suitable diagnostic procedure knowing some motor and fault characteristics. Defining a severity factor as the increase in amplitude of the fault characteristic frequency, with respect to the healthy condition, enables us to study the sensitivity of the electrical diagnostic tools. As a result, it is shown that the relationship between the angular displacement of the current side-bands components at frequencies ( f± fosc) is directly related to the type of induction motor faults. It is also proved that the total instantaneous power diagnostic procedure was observed to exhibit the highest values of the detection criterion in case of mechanical faults while in case of electrical ones the most reliable diagnostic procedure is tightly related to the value of the motor power factor angle and the group motor-load inertia. Finally, simulation and experimental results show good agreement with the fault modeling theoretical results.

  14. Nonlinear servo control of an induction motor with saturation

    SciTech Connect

    Bodson, M.; Chiasson, J.; Novotnak, R.

    1994-12-31

    This work is an extension of the authors` previous work on high-performance induction motor control in which the magnetic model of the motor was assumed to be linear. Saturation of the iron in the main path of the induction machine is taken into account. The saturation is modeled in the dq coordinate frame and the model is then used to design an input-output linearization controller to provide independent (decoupled) control of the speed and flux. With this controller, the flux reference becomes an extra degree of freedom for the designer to help achieve performance objectives. Taking into account saturation, the flux reference is chosen to achieve the optimal torque (maximum for acceleration & minimum for deceleration) at any given speed. The input-output controller is used to provide tracking of a given position & speed trajectory while simultaneously tracking the optimal flux reference. Experimental results are given to validate the approach.

  15. Road load simulator tests of the Gould phase 1 functional model silicon controlled rectifier ac motor controller for electric vehicles

    NASA Technical Reports Server (NTRS)

    Gourash, F.

    1984-01-01

    The test results for a functional model ac motor controller for electric vehicles and a three-phase induction motor which were dynamically tested on the Lewis Research Center road load simulator are presented. Results show that the controller has the capability to meet the SAE-J227a D cycle test schedule and to accelerate a 1576-kg (3456-lb) simulated vehicle to a cruise speed of 88.5 km/hr (55 mph). Combined motor controller efficiency is 72 percent and the power inverter efficiency alone is 89 percent for the cruise region of the D cycle. Steady state test results for motoring, regeneration, and thermal data obtained by operating the simulator as a conventional dynamometer are in agreement with the contractor's previously reported data. The regeneration test results indicate that a reduction in energy requirements for urban driving cycles is attainable with regenerative braking. Test results and data in this report serve as a data base for further development of ac motor controllers and propulsion systems for electric vehicles. The controller uses state-of-the-art silicon controlled rectifier (SCR) power semiconductors and microprocessor-based logic and control circuitry. The controller was developed by Gould Laboratories under a Lewis contract for the Department of Energy's Electric and Hybrid Vehicle program.

  16. Road load simulator tests of the Gould phase 1 functional model silicon controlled rectifier ac motor controller for electric vehicles

    NASA Astrophysics Data System (ADS)

    Gourash, F.

    1984-02-01

    The test results for a functional model ac motor controller for electric vehicles and a three-phase induction motor which were dynamically tested on the Lewis Research Center road load simulator are presented. Results show that the controller has the capability to meet the SAE-J227a D cycle test schedule and to accelerate a 1576-kg (3456-lb) simulated vehicle to a cruise speed of 88.5 km/hr (55 mph). Combined motor controller efficiency is 72 percent and the power inverter efficiency alone is 89 percent for the cruise region of the D cycle. Steady state test results for motoring, regeneration, and thermal data obtained by operating the simulator as a conventional dynamometer are in agreement with the contractor's previously reported data. The regeneration test results indicate that a reduction in energy requirements for urban driving cycles is attainable with regenerative braking. Test results and data in this report serve as a data base for further development of ac motor controllers and propulsion systems for electric vehicles. The controller uses state-of-the-art silicon controlled rectifier (SCR) power semiconductors and microprocessor-based logic and control circuitry. The controller was developed by Gould Laboratories under a Lewis contract for the Department of Energy's Electric and Hybrid Vehicle program.

  17. Voltage oscillatory instability caused by induction motor loads

    SciTech Connect

    Mello, F.P. de; Feltes, J.W.

    1996-08-01

    Isolated power systems which fit the structure of a single equivalent generator supplying an equivalent composite load can experience a voltage oscillatory instability entirely traceable to effects of induction motor loads interacting with automatic voltage regulators. This scenario is one where an AVR properly tuned for open circuit conditions is not necessarily well tuned for the on load condition. The phenomenon is explained and a simple solution through AVR compensation is suggested.

  18. Lyapunov exponent for aging process in induction motor

    NASA Astrophysics Data System (ADS)

    Bayram, Duygu; Ünnü, Sezen Yıdırım; Şeker, Serhat

    2012-09-01

    Nonlinear systems like electrical circuits and systems, mechanics, optics and even incidents in nature may pass through various bifurcations and steady states like equilibrium point, periodic, quasi-periodic, chaotic states. Although chaotic phenomena are widely observed in physical systems, it can not be predicted because of the nature of the system. On the other hand, it is known that, chaos is strictly dependent on initial conditions of the system [1-3]. There are several methods in order to define the chaos. Phase portraits, Poincaré maps, Lyapunov Exponents are the most common techniques. Lyapunov Exponents are the theoretical indicator of the chaos, named after the Russian mathematician Aleksandr Lyapunov (1857-1918). Lyapunov Exponents stand for the average exponential divergence or convergence of nearby system states, meaning estimating the quantitive measure of the chaotic attractor. Negative numbers of the exponents stand for a stable system whereas zero stands for quasi-periodic systems. On the other hand, at least if one of the exponents is positive, this situation is an indicator of the chaos. For estimating the exponents, the system should be modeled by differential equation but even in that case mathematical calculation of Lyapunov Exponents are not very practical and evaluation of these values requires a long signal duration [4-7]. For experimental data sets, it is not always possible to acquire the differential equations. There are several different methods in literature for determining the Lyapunov Exponents of the system [4, 5]. Induction motors are the most important tools for many industrial processes because they are cheap, robust, efficient and reliable. In order to have healthy processes in industrial applications, the conditions of the machines should be monitored and the different working conditions should be addressed correctly. To the best of our knowledge, researches related to Lyapunov exponents and electrical motors are mostly

  19. Fuzzy Logic Based Rotor Health Index of Induction Motor

    NASA Astrophysics Data System (ADS)

    Misra, Rajul; Pahuja, G. L.

    2015-10-01

    This paper presents an experimental study on detection and diagnosis of broken rotor bars in Squirrel Cage Induction Motor (SQIM). The proposed scheme is based on Motor Current Signature Analysis (MCSA) which uses amplitude difference of supply frequency to upper and lower side bands. Initially traditional MCSA has been used for rotor fault detection. It provides rotor health index on full load conditions. However in real practice if a fault occurs motor can not run at full load. To overcome the issue of reduced load condition a Fuzzy Logic based MCSA has been designed, implemented, tested and compared with traditional MCSA. A simulation result shows that proposed scheme is not only capable of detecting the severity of rotor fault but also provides remarkable performance at reduced load conditions.

  20. Optimized performance of solar powered variable speed induction motor drive

    SciTech Connect

    Singh, B.N.; Singh, B.P.; Singh, B.; Chandra, A.; Al-Haddad, K.

    1995-12-31

    This paper deals with the design and development of a photo voltaic (PV) array fed cage induction motor for an isolated water pumping system. A drive system using a chopper circuit to track maximum power from the PV for different solar insolation and a current controlled voltage source inverter (CC-VSI) to optimally match the motor to PV characteristics is presented. The model equations governing interaction of torque and flux producing components of motor current with available solar power is developed for the operation of the system at optimum efficiency. Performance of the system is presented for different realistic operating conditions, which demonstrates its special features for applications such as solar water pumping system, solar vehicles and floor mills located in hilly and isolated areas.

  1. Electromechanical interaction in rotordynamics of cage induction motors

    NASA Astrophysics Data System (ADS)

    Holopainen, Timo P.; Tenhunen, Asmo; Arkkio, Antero

    2005-06-01

    Eccentric rotor motion induces an unbalanced magnetic pull between the rotor and stator of cage induction motors. Recently, a linear parametric model of this eccentricity force due to the arbitrary rotor motion was presented. The purpose of this study is to combine this electromagnetic force model with a simple mechanical rotor model, and further, to demonstrate the rotordynamic response induced by this electromechanical interaction. An electromechanical rotor model is derived on the basis of the Jeffcott rotor with two additional variables for the harmonic currents of the rotor cage. Applying this model, the rotordynamic effects of electromechanical interaction were studied. Three induction motors were used in the numerical examples. The electromechanical parameters of these motors were estimated from the numerical simulations carried out separately. The results obtained show that the electromechanical interaction may decrease the natural frequencies of the rotor, induce additional damping or cause rotordynamic instability. These interaction effects are most significant in motors operating at or near the first bending critical speed. Excluding the potential rotordynamic instability, the numerical results indicate that the electromechanical interaction reduces effectively the unbalance response close to the first bending critical speed.

  2. Proposal of Current Control Method for High-Speed AC Motor System

    NASA Astrophysics Data System (ADS)

    Furutani, Shinichi; Satake, Akira

    In this paper, current control method for High-Speed AC Motor System is proposed. In High-Speed driving operation, Current controller tends to lose stability because of dead time caused by computational delay and Electromagnetic coupling included AC Motor Model. The Main purpose of the proposed method is reduction of dead time on current controller. Proposed method based model predictive control and optimizing of start timing. The Effectiveness of proposed method is confirmed by simulation results.

  3. Evaluation of quasi-square wave inverter as a power source for induction motors

    NASA Technical Reports Server (NTRS)

    Guynes, B. V.; Haggard, R. L.; Lanier, J. R., Jr.

    1977-01-01

    The relative merits of quasi-square wave inverter-motor technology versus a sine wave inverter-motor system were investigated. The empirical results of several tests on various sizes of wye-wound induction motors are presented with mathematical analysis to support the conclusions of the study. It was concluded that, within the limitations presented, the quasi-square wave inverter-motor system is superior to the more complex sine wave system for most induction motor applications in space.

  4. Vectorial Command of Induction Motor Pumping System Supplied by a Photovoltaic Generator

    NASA Astrophysics Data System (ADS)

    Makhlouf, Messaoud; Messai, Feyrouz; Benalla, Hocine

    2011-01-01

    With the continuous decrease of the cost of solar cells, there is an increasing interest and needs in photovoltaic (PV) system applications following standard of living improvements. Water pumping system powered by solar-cell generators are one of the most important applications. The fluctuation of solar energy on one hand, and the necessity to optimise available solar energy on the other, it is useful to develop new efficient and flexible modes to control motors that entrain the pump. A vectorial control of an asynchronous motor fed by a photovoltaic system is proposed. This paper investigates a photovoltaic-electro mechanic chain, composed of a PV generator, DC-AC converter, a vector controlled induction motor and centrifugal pump. The PV generator is forced to operate at its maximum power point by using an appropriate search algorithm integrated in the vector control. The optimization is realized without need to adding a DC-DC converter to the chain. The motor supply is also ensured in all insolation conditions. Simulation results show the effectiveness and feasibility of such an approach.

  5. Electric motor model repair specifications

    SciTech Connect

    1995-08-01

    These model repair specifications list the minimum requirements for repair and overhaul of polyphase AC squireel cage induction motors. All power ranges, voltages, and speeds of squirrel cage motors are covered.

  6. Method and system for determining induction motor speed

    DOEpatents

    Parlos, Alexander G.; Bharadwaj, Raj M.

    2004-03-30

    A non-linear, semi-parametric neural network-based adaptive filter is utilized to determine the dynamic speed of a rotating rotor within an induction motor, without the explicit use of a speed sensor, such as a tachometer, is disclosed. The neural network-based filter is developed using actual motor current measurements, voltage measurements, and nameplate information. The neural network-based adaptive filter is trained using an estimated speed calculator derived from the actual current and voltage measurements. The neural network-based adaptive filter uses voltage and current measurements to determine the instantaneous speed of a rotating rotor. The neural network-based adaptive filter also includes an on-line adaptation scheme that permits the filter to be readily adapted for new operating conditions during operations.

  7. Demodulation circuit for AC motor current spectral analysis

    DOEpatents

    Hendrix, Donald E.; Smith, Stephen F.

    1990-12-18

    A motor current analysis method for the remote, noninvasive inspection of electric motor-operated systems. Synchronous amplitude demodulation and phase demodulation circuits are used singly and in combination along with a frequency analyzer to produce improved spectral analysis of load-induced frequencies present in the electric current flowing in a motor-driven system.

  8. Advanced AC permanent magnet axial flux disc motor for electric passenger vehicle

    NASA Technical Reports Server (NTRS)

    Kliman, G. B.

    1982-01-01

    An ac permanent magnet axial flux disc motor was developed to operate with a thyristor load commutated inverter as part of an electric vehicle drive system. The motor was required to deliver 29.8 kW (40 hp) peak and 10.4 kW (14 hp) average with a maximum speed of 11,000 rpm. It was also required to run at leading power factor to commutate the inverter. Three motors were built.

  9. Analytical calculation of the RFOC method in single-phase induction motor

    NASA Astrophysics Data System (ADS)

    Jannati, M.; Monadi, A.; Idris, N. R. N.; Faudzi, A. A. M.

    2016-05-01

    This study discusses the different techniques for speed control of single-phase induction motor with two asymmetrical main and auxiliary windings based on Rotor Field-Oriented Control (RFOC) method. In the presented methods, transformation matrices are introduced and applied to the equations of single-phase induction motor. It is shown by applying these rotational transformations to the unbalanced equations of single-phase induction motor, equations of single-phase induction motor are transformed into symmetrical equations. These rotational transformations are achieved based from the steady-state equivalent circuit of single-phase induction motor. Finally, a method for RFOC of single-phase induction motor is proposed. Results show the good performance of the proposed method.

  10. AC Servo Motor Based Position Sensorless Control System Making Use of Springs

    NASA Astrophysics Data System (ADS)

    Shimada, Akira; Kishiwada, Yu; Arimura, Michiyo

    This paper describes a position sensorless control technique on AC servo motor based position control systems. Shimada et al. had previously presented a paper on a DC servo motor based position sensorless control technique using mechanical springs. It was based on a point of view that mechanical springs form the key components for the observability. On the basis of the result obtained from the successful experiment, we assumed that the AC servo motor position sensorless control system would be identical. Using vector control, the controller needs the data of the magnetic pole position on the rotor of the AC servo motor. It is not perfect sensorless control, since it use a rotary encoder. However, we introduce it and demonstrate the expreimental results as an initial step in the new control technology.

  11. System and method for monitoring and controlling stator winding temperature in a de-energized AC motor

    DOEpatents

    Lu, Bin; Luebke, Charles John; Habetler, Thomas G.; Zhang, Pinjia; Becker, Scott K.

    2011-12-27

    A system and method for measuring and controlling stator winding temperature in an AC motor while idling is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of a multi-phase AC motor. The circuit further includes a plurality of switching devices to control current flow and terminal voltages in the multi-phase AC motor and a controller connected to the circuit. The controller is configured to activate the plurality of switching devices to create a DC signal in an output of the motor control device corresponding to an input to the multi-phase AC motor, determine or estimate a stator winding resistance of the multi-phase AC motor based on the DC signal, and estimate a stator temperature from the stator winding resistance. Temperature can then be controlled and regulated by DC injection into the stator windings.

  12. Augmenting Plasticity Induction in Human Motor Cortex by Disinhibition Stimulation.

    PubMed

    Cash, Robin F H; Murakami, Takenobu; Chen, Robert; Thickbroom, Gary W; Ziemann, Ulf

    2016-01-01

    Cellular studies showed that disinhibition, evoked pharmacologically or by a suitably timed priming stimulus, can augment long-term plasticity (LTP) induction. We demonstrated previously that transcranial magnetic stimulation evokes a period of presumably GABA(B)ergic late cortical disinhibition (LCD) in human primary motor cortex (M1). Here, we hypothesized that, in keeping with cellular studies, LCD can augment LTP-like plasticity in humans. In Experiment 1, patterned repetitive TMS was applied to left M1, consisting of 6 trains (intertrain interval, 8 s) of 4 doublets (interpulse interval equal to individual peak I-wave facilitation, 1.3-1.5 ms) spaced by the individual peak LCD (interdoublet interval (IDI), 200-250 ms). This intervention (total of 48 pulses applied over ∼45 s) increased motor-evoked potential amplitude, a marker of corticospinal excitability, in a right hand muscle by 147% ± 4%. Control experiments showed that IDIs shorter or longer than LCD did not result in LTP-like plasticity. Experiment 2 indicated topographic specificity to the M1 hand region stimulated by TMS and duration of the LTP-like plasticity of 60 min. In conclusion, GABA(B)ergic LCD offers a powerful new approach for augmenting LTP-like plasticity induction in human cortex. We refer to this protocol as disinhibition stimulation (DIS). PMID:25100853

  13. Motor technology for mining applications advances

    SciTech Connect

    Fiscor, S.

    2009-08-15

    AC motors are steadily replacing DC motors in mining and mineral processing equipment, requiring less maintenance. The permanent magnet rotor, or the synchronous motor, has enabled Blador to introduce a line of cooling tower motors. Synchronous motors are soon likely to take over from the induction motor. 1 photo.

  14. Diagnostics of DC and Induction Motors Based on the Analysis of Acoustic Signals

    NASA Astrophysics Data System (ADS)

    Glowacz, A.

    2014-10-01

    In this paper, a non-invasive method of early fault diagnostics of electric motors was proposed. This method uses acoustic signals generated by electric motors. Essential features were extracted from acoustic signals of motors. A plan of study of acoustic signals of electric motors was proposed. Researches were carried out for faultless induction motor, induction motor with one faulty rotor bar, induction motor with two faulty rotor bars and flawless Direct Current, and Direct Current motor with shorted rotor coils. Researches were carried out for methods of signal processing: log area ratio coefficients, Multiple signal classification, Nearest Neighbor classifier and the Bayes classifier. A pattern creation process was carried out using 40 samples of sound. In the identification process 130 five-second test samples were used. The proposed approach will also reduce the costs of maintenance and the number of faulty motors in the industry.

  15. Analysis of a three phase induction motor directly from Maxwell's equations

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Shayak

    2012-01-01

    The torque developed in a three phase AC squirrel cage motor is usually expressed in terms of resistances and reactances of the stator, the rotor, and the motor as a whole. We use Maxwell's equations to find the torque in terms of geometrical parameters. This formulation allows us to estimate the torque developed by a motor without knowing the details of its circuitry.

  16. Introducing AC Inductive Reactance with a Power Tool

    ERIC Educational Resources Information Center

    Bryant, Wesley; Baker, Blane

    2016-01-01

    The concept of reactance in AC electrical circuits is often non-intuitive and difficult for students to grasp. In order to address this lack of conceptual understanding, classroom exercises compare the predicted resistance of a power tool, based on electrical specifications, to measured resistance. Once students discover that measured resistance…

  17. Design of a novel phase-decoupling permanent magnet brushless ac motor

    NASA Astrophysics Data System (ADS)

    Cui, Wei; Chau, K. T.; Jiang, J. Z.; Fan, Ying

    2005-05-01

    This paper presents a phase-decoupling permanent magnet brushless ac motor which can offer better controllability, faster response, and smoother torque than its counterparts. The key is due to its different motor configuration and simple scalar control. The motor configuration is so unique that it inherently offers the features of phase decoupling, flux focusing, and flux shaping, hence achieving independent phase control, fast response, and smooth torque. The scalar control is fundamentally different from the complicated vector control. It can achieve direct torque control through independent control of the phase currents. The proposed motor is prototyped and experimentally verified.

  18. Vibration of Induction Motor Rotor in Rotating Magnetic Field

    NASA Astrophysics Data System (ADS)

    Iwata, Yoshio; Sato, Hidenori; Komatsuzaki, Toshihiko; Saito, Takuhiro

    The rotor vibration of two-pole induction motor with rotating magnetic field has been investigated. The vibration is measured at any relative location of the stator and the rotor with various power supply frequencies in the experiment and is analyzed in consideration of mechanical factors of the rotor. The following conclusion is obtained through the experiment and the analysis; (1) 2ω vibration of twice the power supply frequency ω is generated because of offset between the stator center and the gyrational center of the rotor. (2) Two vibrations of ω(1-s) and ω(1+s) where s is slip ratio are generated because of the rotor unbalance or the disagreement between the gyrational center and geometrical center of the rotor. (3) An unstable vibration is predicted in the analysis when the power supply frequency is equal to natural frequency of the rotor, however, the unstable vibration was not generated in the experiment because of the damping.

  19. Dynamic Performance of Subway Vehicle with Linear Induction Motor System

    NASA Astrophysics Data System (ADS)

    Wu, Pingbo; Luo, Ren; Hu, Yan; Zeng, Jing

    The light rail vehicle with Linear Induction Motor (LIM) bogie, which is a new type of urban rail traffic tool, has the advantages of low costs, wide applicability, low noise, simple maintenance and better dynamic behavior. This kind of vehicle, supported and guided by the wheel and rail, is not driven by the wheel/rail adhesion force, but driven by the electromagnetic force between LIM and reaction plate. In this paper, three different types of suspensions and their characteristic are discussed with considering the interactions both between wheel and rail and between LIM and reaction plate. A nonlinear mathematical model of the vehicle with LIM bogie is set up by using the software SIMPACK, and the electromechanical model is also set up on Simulink roof. Then the running behavior of the LIM vehicle is simulated, and the influence of suspension on the vehicle dynamic performance is investigated.

  20. Induction motor control system with voltage controlled oscillator circuit

    NASA Technical Reports Server (NTRS)

    Nola, F. J.; Currie, J. R.; Reid, H., Jr. (Inventor)

    1973-01-01

    A voltage controlled oscillator circuit is reported in which there are employed first and second differential amplifiers. The first differential amplifier, being employed as an integrator, develops equal and opposite slopes proportional to an input voltage, and the second differential amplifier functions as a comparator to detect equal amplitude positive and negative selected limits and provides switching signals which gate a transistor switch. The integrating differential amplifier is switched between charging and discharging modes to provide an output of the first differential amplifier which upon the application of wave shaping provides a substantially sinusoidal output signal. A two phased version with a second integrator provides a second 90 deg phase shifted output for induction motor control.

  1. Analytical analysis of single- and three-phase induction motors

    SciTech Connect

    Davey, K.R.

    1998-09-01

    The analysis of single and multiphase induction motors continues to represent a challenge to researchers in computational electromagnetics due to the presence of r{Omega} x B electric fields. This contribution cannot be inserted into the Green`s function for boundary element codes; finite difference and finite element approaches are forced to hard code these effects, compensating at high speeds with upwinding techniques. The direct computation of these affects using transfer relations in a linear environment offers an analytical backdrop both for benchmark testing numerical codes and for design assessment criteria. In addition to torque-speed predictions, the terminal relations and total power dissipation in the rotor are computed for an exposed winding three-phase and single-phase machine.

  2. Speed sensorless hybrid vector controlled induction motor drive

    SciTech Connect

    Bose, B.K.; Simoes, M.G.; Crecelius, D.R.; Rajashekara, K.; Martin, R.

    1995-12-31

    The paper describes a speed and flux sensorless vector-controlled induction motor drive primarily aimed for electric vehicle type applications. The stator flux oriented drive starts at zero speed in indirect vector control mode, transitions to direct vector control mode as the speed develops, and then transitions back to indirect vector control at zero speed. The vector control uses stator flux orientation in both indirect and direct vector control modes with the stator resistance variation compensated by measurement of stator temperature. The problem of integration at low stator frequency is solved by cascaded low pass filters with programmable time constants. The control strategy of the four-quadrant drive has been analyzed, validated by simulation study, and finally evaluated by experimental study on a laboratory 5 hp drive system.

  3. FUZZY-LOGIC-BASED CONTROLLERS FOR EFFICIENCY OPTIMIZATION OF INVERTER-FED INDUCTION MOTOR DRIVES

    EPA Science Inventory

    This paper describes a fuzzy-logic-based energy optimizing controller to improve the efficiency of induction motor/drives operating at various load (torque) and speed conditions. Improvement of induction motor efficiency is important not only from the considerations of energy sav...

  4. Construction of AC Motor Controllers for NOvA Experiment Upgrades

    SciTech Connect

    Cooley, Patrick; /Fermilab

    2011-08-04

    I have been constructing Alternating Current (AC) motor controllers for manipulation of particle beam detectors. The capability and reliability of these motor controllers are essential to the Laboratory's mission of accurate analysis of the particle beam's position. The device is moved in and out of the beam's path by the motor controller followed by the Neutrinos at the Main Injector Off-Axis {nu}{sub e} Appearance (NOvA) Experiment further down the beam pipe. In total, I built and tested ten ac motor controllers for new beam operations in the NOvA experiment. These units will prove to be durable and provide extremely accurate beam placement for NOvA Experiment far into the future.

  5. Effective method to measure back emfs and their harmonics of permanent magnet ac motors

    NASA Astrophysics Data System (ADS)

    Jiang, Q.; Bi, C.; Lin, S.

    2006-04-01

    As the HDD spindle motors become smaller and smaller, the back electromotive forces (emfs) measurement faces the new challenges due to their low inertias and small sizes. This article proposes a novel method to measure the back emfs and their harmonic components of PM ac motors only through a freewheeling procedure. To eliminate the influence of the freewheeling deceleration, the phase flux linkages are employed to obtain the back emf amplitudes and phases of the fundamental and harmonic components by using finite Fourier series analysis. The proposed method makes the freewheeling measurement of the back emfs and their harmonics accurate and fast. It is especially useful for the low inertia PM ac motors, such as spindle motors for small form factor HDDs.

  6. Sensorless Detection of Induction Motor Rotor Faults Using the Clarke Vector Approach

    NASA Astrophysics Data System (ADS)

    Vaimann, Toomas; Kallaste, Ants; Kilk, Aleksander

    2011-01-01

    Due to their rugged build, simplicity and cost effective performance, induction motors are used in a vast number of industries, where they play a significant role in responsible operations, where faults and downtimes are either not desirable or even unthinkable. As different faults can affect the performance of the induction motors, among them broken rotor bars, it is important to have a certain condition monitoring or diagnostic system that is guarding the state of the motor. This paper deals with induction motor broken rotor bars detection, using Clarke vector approach.

  7. Neural and Fuzzy Adaptive Control of Induction Motor Drives

    SciTech Connect

    Bensalem, Y.; Sbita, L.; Abdelkrim, M. N.

    2008-06-12

    This paper proposes an adaptive neural network speed control scheme for an induction motor (IM) drive. The proposed scheme consists of an adaptive neural network identifier (ANNI) and an adaptive neural network controller (ANNC). For learning the quoted neural networks, a back propagation algorithm was used to automatically adjust the weights of the ANNI and ANNC in order to minimize the performance functions. Here, the ANNI can quickly estimate the plant parameters and the ANNC is used to provide on-line identification of the command and to produce a control force, such that the motor speed can accurately track the reference command. By combining artificial neural network techniques with fuzzy logic concept, a neural and fuzzy adaptive control scheme is developed. Fuzzy logic was used for the adaptation of the neural controller to improve the robustness of the generated command. The developed method is robust to load torque disturbance and the speed target variations when it ensures precise trajectory tracking with the prescribed dynamics. The algorithm was verified by simulation and the results obtained demonstrate the effectiveness of the IM designed controller.

  8. Neural and Fuzzy Adaptive Control of Induction Motor Drives

    NASA Astrophysics Data System (ADS)

    Bensalem, Y.; Sbita, L.; Abdelkrim, M. N.

    2008-06-01

    This paper proposes an adaptive neural network speed control scheme for an induction motor (IM) drive. The proposed scheme consists of an adaptive neural network identifier (ANNI) and an adaptive neural network controller (ANNC). For learning the quoted neural networks, a back propagation algorithm was used to automatically adjust the weights of the ANNI and ANNC in order to minimize the performance functions. Here, the ANNI can quickly estimate the plant parameters and the ANNC is used to provide on-line identification of the command and to produce a control force, such that the motor speed can accurately track the reference command. By combining artificial neural network techniques with fuzzy logic concept, a neural and fuzzy adaptive control scheme is developed. Fuzzy logic was used for the adaptation of the neural controller to improve the robustness of the generated command. The developed method is robust to load torque disturbance and the speed target variations when it ensures precise trajectory tracking with the prescribed dynamics. The algorithm was verified by simulation and the results obtained demonstrate the effectiveness of the IM designed controller.

  9. Loss Calculation of Induction Motors Considering Harmonic Electromagnetic Fields in Stator and Rotor

    NASA Astrophysics Data System (ADS)

    Yamazaki, Katsumi

    A method of loss calculation for induction motors is proposed. The combined 3D-2D time stepping finite element analysis is carried out to obtain the copper loss and the time-variation of the magnetic field in the motor. The iron loss is calculated approximately considering the time-variation of the magnetic field direction and the minor hysteresis loops caused by the time-harmonic fields using practical computer resources. The proposed method is applied to 4 types of induction motors, which are the solid rotor induction motors with/without slot and the cage induction motors with/without skew. The measured and the calculated total losses and the iron losses agree well in all cases. The differences of the loss distributions of each motor are also compared and investigated.

  10. Field assessment of induction motor efficiency through air-gap torque

    SciTech Connect

    Hsu, J.S.; Sorenson, P.L.

    1995-11-01

    Induction motors are the most popular motors used in industry. This paper further suggests the use of air-gap torque method to evaluate their efficiency and load changes. The fundamental difference between Method E and the air-gap torque method is discussed. Efficiency assessments conducted on induction motors under various conditions show the accuracy and potential of the air-gap torque method.

  11. Method and apparatus for monitoring the rotating frequency of de-energized induction motors

    DOEpatents

    Mikesell, H.E.; Lucy, E.

    1998-02-03

    The rotational speed of a coasting induction motor is measured by sensing e residual electrical voltages at the power terminals of the motor, thus eliminating the need for conventional tachometer equipment, additional mechanical components or modifications to the induction motor itself. The power terminal voltage signal is detected and transformed into a DC voltage proportional to the frequency of the signal. This DC voltage can be input to the control system of a variable frequency motor controller to regulate the output characteristics thereof relative to the speed of the coasting motor. 6 figs.

  12. Method and apparatus for monitoring the rotating frequency of de-energized induction motors

    DOEpatents

    Mikesell, Harvey E.; Lucy, Eric

    1998-01-01

    The rotational speed of a coasting induction motor is measured by sensing e residual electrical voltages at the power terminals of the motor, thus eliminating the need for conventional tachometer equipment, additional mechanical components or modifications to the induction motor itself. The power terminal voltage signal is detected and transformed into a DC voltage proportional to the frequency of the signal. This DC voltage can be input to the control system of a variable frequency motor controller to regulate the output characteristics thereof relative to the speed of the coasting motor.

  13. Rotor resistance estimator design for indirect field-oriented induction motors

    NASA Astrophysics Data System (ADS)

    Zhao, Jianhui; Wu, Zhong

    2006-11-01

    Exact information of the rotor resistance is the key to realize high-performance indirect field-oriented control of the induction motors. However, rotor resistance is time-varying when the motor works. Therefore, a new estimator of the rotor resistance is designed for the indirect field-oriented induction motors to attenuate the effect of the rotor resistance uncertainty. This estimator is derived from the steady-state procedure of the rotor flux using Lyapunov stability theory. Furthermore, this estimator is shown to be able to minimize the steady-state error the rotor flux and improve the control performance of the induction motor drive effectively. Compared with the previous studies, this estimator has a simple form and is easy to implement. Simulation results of a certain IFOC induction motor indicate that the estimator presented above is feasible.

  14. Novel indices for broken rotor bars fault diagnosis in induction motors using wavelet transform

    NASA Astrophysics Data System (ADS)

    Ebrahimi, Bashir Mahdi; Faiz, Jawad; Lotfi-fard, S.; Pillay, P.

    2012-07-01

    This paper introduces novel indices for broken rotor bars diagnosis in three-phase induction motors based on wavelet coefficients of stator current in a specific frequency band. These indices enable to diagnose occurrence and determine number of broken bars in different loads precisely. Besides thanks to the suitability of wavelet transform in transient conditions, it is possible to detect the fault during the start-up of the motor. This is important in the case of start-up of large induction motors with long starting time and also motors with frequent start-up. Furthermore, broken rotor bars in induction motor are detected using spectra analysis of the stator current. It is also shown that rise of number of broken bars and load levels increases amplitude of the particular side-band components of the stator currents in the faulty case. An induction motor with 1, 2, 3 and 4 broken bars at the rated load and the motor with 4 broken bars at no-load, 33%, 66%, 100% and 133% rated load are investigated. Time stepping finite element method is used for modeling broken rotor bars faults in induction motors. In this modeling, effects of the stator winding distribution, stator and rotor slots, geometrical and physical characteristics of different parts of the motor and non-linearity of the core materials are taken into account. The simulation results are are verified by the experimental results.

  15. Integrated Cooling System for Induction Motor Traction Drives, CARAT Program Phase Two Final Report

    SciTech Connect

    Konrad, Charles E.

    2002-12-03

    This Program is directed toward improvements in electric vehicle/hybrid electric vehicle traction systems, and in particular, the development of a low cost, highly efficient, compact traction motor-controller system targeted for high volume automotive use. Because of the complex inter-relationships between the motor and the controller, the combination of motor and controller must be considered as a system in the design and evaluation of overall cost and performance. The induction motor is ideally suited for use as a traction motor because of its basic ruggedness, low cost, and high efficiency. As one can see in Figure 1.1, the induction motor traction drive has been continually evolving through a succession of programs spanning the past fifteen years. VPT marketed an induction motor-based traction drive system, the EV2000, which proved to be a reliable, high performance system that was used in a wide range of vehicles. The EV2000 drives evolved from the Modular Electric Vehicle Program (MEVP) and has been used in vehicles ranging in size from 3,000 lb. autos and utility vans, to 32,000 lb. city transit buses. Vehicles powered by the EV2000 induction motor powertrain have accumulated over 2 million miles of service. The EV2000 induction motor system represents 1993 state-of-the-art technology, and evolved from earlier induction motor programs that drove induction motor speeds up to 15,000 rpm to reduce the motor size and cost. It was recognized that the improvements in power density and motor cost sought in the PNGV program could only be achieved through increases in motor speed. Esson’s Rule for motor power clearly states that the power obtainable from a given motor design is the product of motor speed and volume. In order to meet the CARAT Program objectives, the maximum speed goal of the induction motor designed in this Program was increased from 15,000 rpm to 20,000 rpm while maintaining the efficiency and durability demonstrated by lower speed designs done in

  16. An Inverter-Driven Induction Motor System with a Deadlock Breaking Capability

    NASA Astrophysics Data System (ADS)

    Ichikawa, Takuto; Yoshida, Toshiya; Miyashita, Osamu

    Induction motors are very widely used in various industrial applications. In semiconductor manufacturing processes, deadlock failure of pumps may occur by the adhering of glass material contained in the gas to the rotor. This can lead to the shutdown of the manufacturing plant. Therefore, a countermeasure to prevent deadlocking of a motor is required. This paper proposes a method for generating an impulse torque in an induction motor fed by an inverter. The proposed inverter circuit is composed of a conventional inverter and a few additional relays. The on-and-off control of the relays supplies an appropriate magnetizing current and a large torque current from the dc-link capacitor. In experiment, a 1.5-kW cage-type induction motor generated a torque that was approximately seven times larger than the rated torque of the motor. This large impulse torque is useful for breaking the motor deadlock.

  17. Aerospace induction motor actuators driven from a 20-kHz power link

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1990-01-01

    Aerospace electromechanical actuators utilizing induction motors are under development in sizes up to 40 kW. While these actuators have immediate application to the Advanced Launch System (ALS) program, several potential applications are currently under study including the Advanced Aircraft Program. Several recent advances developed for the Space Station Freedom have allowed induction motors to be selected as a first choice for such applications. Among these technologies are bi-directional electronics and high frequency power distribution techniques. Each of these technologies are discussed with emphasis on their impact upon induction motor operation.

  18. Energy-saving technology of vector controlled induction motor based on the adaptive neuro-controller

    NASA Astrophysics Data System (ADS)

    Engel, E.; Kovalev, I. V.; Karandeev, D.

    2015-10-01

    The ongoing evolution of the power system towards a Smart Grid implies an important role of intelligent technologies, but poses strict requirements on their control schemes to preserve stability and controllability. This paper presents the adaptive neuro-controller for the vector control of induction motor within Smart Gird. The validity and effectiveness of the proposed energy-saving technology of vector controlled induction motor based on adaptive neuro-controller are verified by simulation results at different operating conditions over a wide speed range of induction motor.

  19. Superconducting AC motor for centrifugal liquid helium pump

    SciTech Connect

    Rivetti, A.; Goria, R.; Martini, G.

    1982-01-01

    The behavior of flowmeters in liquid and supercritical helium is studied. A description is given of the motor and experimental apparatus. The initial results (torque vs. efficiency and power vs. slip) are chartered. The results obtained with an external rotating shield (torque vs. efficiency and power vs. slip) are also charted. One rotor provided a higher power particularly at the highest frequencies, provided that the critical point is not exceeded. Another rotor gives a better efficiency, particularly at the lowest frequencies. Recommendations for adopting a rotor design are given.

  20. Efficacy of an AC sinusoidal electric field for apoptosis induction in lung carcinoma cells (A549)

    NASA Astrophysics Data System (ADS)

    Park, Hyoun-Hyang; Lee, Seung S.; Hoon Lee, Dae

    2012-08-01

    An AC sinusoidal electric field was applied to lung carcinoma cells for the induction of apoptosis. The occurrence of apoptosis was determined by analysis of Annexin V/PI and DNA fragmentation. Additional evidence of apoptosis was confirmed by caspase-3 cleavage and disruption of mitochondrial membrane potential. These results demonstrated that the expression of apoptosis can be controlled by varying the magnitude and the duration of the field, and that the application of an AC electric field can stimulate the apoptosis via mitochondria-mediated pathway.

  1. AC motor and generator requirements for isolated WECS

    NASA Technical Reports Server (NTRS)

    Park, G. L.; Mccleer, P. J.; Hanson, B.; Weinberg, B.; Krauss, O.

    1985-01-01

    After surveying electrically driven loads used on productive farms, the investigators chose three pumps for testing at voltages and frequencies far outside the normal operating range. These loads extract and circulate water and move heat via air, and all are critical to farm productivity. The object was to determine the envelope of supply voltage and frequency over which these loads would operate stably for time intervals under 1 hour. This information is among that needed to determine the feasibility of supplying critical loads, in case of a utility outage, from a wind driven alternator whose output voltage and frequency will vary dramatically in most continental wind regimes. Other related work is surveyed. The salient features and limitations of the test configurations used and the data reduction are described. The development of simulation models suitable for a small computer are outlined. The results are primarily displayed on the voltage frequency plane with the general conclusion that the particular pump models considered will operate over the range of 50 to 90 Hz and a voltage band which starts below rated, decreases as frequency decreases, and is limited on the high side by excessive motor heating. For example, centrifugal pump operating voltage ranges as extensive .4 to 1.4 appear possible. Particular problems with starting, stalling due to lack of motor torque, high speed cavitation, and likely overheating are addressed in a listing of required properties for wind driven alternators and their controllers needed for use in the isolated or stand alone configuration considered.

  2. AC motor and generator requirements for isolated WECS

    NASA Astrophysics Data System (ADS)

    Park, G. L.; McCleer, P. J.; Hanson, B.; Weinberg, B.; Krauss, O.

    1985-10-01

    After surveying electrically driven loads used on productive farms, the investigators chose three pumps for testing at voltages and frequencies far outside the normal operating range. These loads extract and circulate water and move heat via air, and all are critical to farm productivity. The object was to determine the envelope of supply voltage and frequency over which these loads would operate stably for time intervals under 1 hour. This information is among that needed to determine the feasibility of supplying critical loads, in case of a utility outage, from a wind driven alternator whose output voltage and frequency will vary dramatically in most continental wind regimes. Other related work is surveyed. The salient features and limitations of the test configurations used and the data reduction are described. The development of simulation models suitable for a small computer are outlined. The results are primarily displayed on the voltage frequency plane with the general conclusion that the particular pump models considered will operate over the range of 50 to 90 Hz and a voltage band which starts below rated, decreases as frequency decreases, and is limited on the high side by excessive motor heating. For example, centrifugal pump operating voltage ranges as extensive .4 to 1.4 appear possible. Particular problems with starting, stalling due to lack of motor torque, high speed cavitation, and likely overheating are addressed in a listing of required properties for wind driven alternators and their controllers needed for use in the isolated or stand alone configuration considered.

  3. Influence analysis of structural parameters on electromagnetic properties of HTS linear induction motor

    NASA Astrophysics Data System (ADS)

    Zhao, J.; Zheng, T. Q.; Zhang, W.; Fang, J.; Liu, Y. M.

    2011-11-01

    A new type high temperature superconductor linear induction motor is designed and analyzed as a prototype to ensure applicability aimed at industrial motors. Made of Bi-2223/Ag, primary windings are distributed with the double-layer concentrated structure. The motor is analyzed by 2D electromagnetic Finite Element Method to get magnetic field distribution, thrust force, vertical force and so on. The critical current of motor and the electromagnetic force are mostly decided by the leakage flux density of primary slot and by the main magnetic flux and eddy current respectively. The structural parameters of motor have a great influence on the distribution of magnetic field. Under constant currents, the properties of motor are analyzed with different slot widths, slot heights and winding turns. The properties of motor, such as the maximum slot leakage flux density, motor thrust and motor vertical force, are analyzed with different structural parameters.

  4. Modelling and simulation of voltage inverter fed induction motor with stator flux orientation

    SciTech Connect

    Rafajlovski, G.; Ratz, E.; Manov, D.; Mircevski, S.

    1995-12-31

    This paper deals with the application of a non-linear control technique in a three phase inverter-fed induction motor. Also mathematical model for dynamic analysis of an induction motor and voltage controlled inverter in stator coordinate system is described. Digital simulation has been utilized to prove the performance and simplicity of the induction motor mathematical formulation. These models can be easily transformed for freely chosen rotating frame of reference. In this control system of stator flux controlled induction motor the instantaneous values of the flux and torque are calculated from only the primary current variables. By using instantaneous voltage space vectors with selection of optimum inverter switching modes employing vector modulation technique, the direct control of torque and stator flux is achieved.

  5. Optimal efficiency vector control of induction motor drive system for drum washing machine

    NASA Astrophysics Data System (ADS)

    Lee, Won Cheol; Yu, Jae Sung; Jang, Bong An; Won, Chung Yuen

    2005-12-01

    In home appliances, electric energy is optimally controlled by using power electronics technology, creating a comfortable environment in terms of energy saving, low sound generation, and reduced time consumption. Usually simplicity and robustness make the three phase induction motor attractive for use in domestic appliance, including washing machines. Two main types of domestic washing machine have evolved. We focus on efficiency of the front loading machine favored in Europe, which has a horizontal drum axis. This paper presents the control algorithm for optimal efficiency drives of an induction motor for drum washing machine. This system uses a simple model of the induction motor that include equations of the iron losses. The proposed optimal efficiency control algorithm calculates commands of the reference torque and flux currents for the flux oriented control of the induction motor. The proposed algorithm is verified through digital simulation.

  6. Propulsive characteristics of a novel linear hybrid motor with both induction and synchronous operations

    SciTech Connect

    Jeon, W.J.; Katoh, S.; Iwamoto, T.; Kamiya, Y.; Onuki, T.

    1999-09-01

    This paper treats a novel linear hybrid motor (LHM) by both induction and synchronous operations. The proposed motor consists of one pair of linear synchronous motors (LSMs) and a linear induction motor (LIM). The primary-cores of both LSM and LIM have a common ring winding, and the secondary solid-conductor is arranged in both LIM and the interpole space of LSM. The feature of the motor is that the undesirable vertical force in LSM is offset by the symmetrical double-sided construction and the secondary is capable of self-starting by induction operation. From the investigation by the three-dimensional finite element analysis and experiment, the authors derive an optimal exciting condition for starting, and then verify that the proposed LHM is effective for practical use.

  7. Use of fuzzy inference system for condition monitoring of induction motor

    NASA Astrophysics Data System (ADS)

    Janier, Josefina B.; Zaim Zaharia, M. F.; Karim, Samsul Ariffin Abd.

    2012-09-01

    Three phase induction motors are commonly used in industry due to its robustness, simplicity of its construction and high reliability. The tasks performed by these motors grow increasingly complex because of modern industries hence there is a need to determine the faults. Early detection of faults will reduce an unscheduled machine downtime that can upset production deadlines and may cause heavy financial losses. This paper is focused in developing a computer based system using Fuzzy Inference system's membership function. An unusual increase in vibration of the motor could be an indicator of faulty condition hence the vibration of the motor of an induction motor was used as an input, whereas the output is the motor condition. An inference system of the Fuzzy Logic was created to classify the vibration characteristics of the motor which is called vibration analysis. The system classified the motor of the gas distribution pump condition as from 'acceptable' to 'monitor closely'. The early detection of unusual increase in vibration of the induction motor is an important part of a predictive maintenance for motor driven machinery.

  8. Adaptive speed/position control of induction motor based on SPR approach

    NASA Astrophysics Data System (ADS)

    Lee, Hou-Tsan

    2014-11-01

    A sensorless speed/position tracking control scheme for induction motors is proposed subject to unknown load torque via adaptive strictly positive real (SPR) approach design. A special nonlinear coordinate transform is first provided to reform the dynamical model of the induction motor. The information on rotor fluxes can thus be derived from the dynamical model to decide on the proportion of input voltage in the d-q frame under the constraint of the maximum power transfer property of induction motors. Based on the SPR approach, the speed and position control objectives can be achieved. The proposed control scheme is to provide the speed/position control of induction motors while lacking the knowledge of some mechanical system parameters, such as the motor inertia, motor damping coefficient, and the unknown payload. The adaptive control technique is thus involved in the field oriented control scheme to deal with the unknown parameters. The thorough proof is derived to guarantee the stability of the speed and position of control systems of induction motors. Besides, numerical simulation and experimental results are also provided to validate the effectiveness of the proposed control scheme.

  9. Sound based induction motor fault diagnosis using Kohonen self-organizing map

    NASA Astrophysics Data System (ADS)

    Germen, Emin; Başaran, Murat; Fidan, Mehmet

    2014-05-01

    The induction motors, which have simple structures and design, are the essential elements of the industry. Their long-lasting utilization in critical processes possibly causes unavoidable mechanical and electrical defects that can deteriorate the production. The early diagnosis of the defects in induction motors is crucial in order to avoid interruption of manufacturing. In this work, the mechanical and the electrical faults which can be observed frequently on the induction motors are classified by means of analysis of the acoustic data of squirrel cage induction motors recorded by using several microphones simultaneously since the true nature of propagation of sound around the running motor provides specific clues about the types of the faults. In order to reveal the traces of the faults, multiple microphones are placed in a hemispherical shape around the motor. Correlation and wavelet-based analyses are applied for extracting necessary features from the recorded data. The features obtained from same types of motors with different kind of faults are used for the classification using the Self-Organizing Maps method. As it is described in this paper, highly motivating results are obtained both on the separation of healthy motor and faulty one and on the classification of fault types.

  10. Three-phase induction motor integrated with a magnetic frequency changer

    NASA Astrophysics Data System (ADS)

    Goleman, Ryszard

    2003-01-01

    The new solution of the high-speed induction motor model is presented. The basic structural part of the motor is magnetic circuit with non-linear elements in which the third harmonic of the flux is generated. The finite element method is used to solve the coupled equations for the magnetic field, the stator windings and conductors of the rotor.

  11. Fine-tuning motor torque

    SciTech Connect

    O`Connor, L.

    1996-01-01

    Direct-torque control, a new method of regulating the output of ac induction motors, provides a swift response to input commands. A new variable-speed ac motor drive system that responds to torque input commands 10 times faster than current state-of-the-art drives has been developed by ABB Industrial Systems Inc. in New Berlin, Wis. The new control system, called the ACS 600, provides an alternative to drive systems that use sophisticated flux vector control or more routine pulse width modulation--the primary methods of regulating the output of ac induction motors. The ACS 600 is suitable for use in single motor applications that require a standard level of performance, such as conveyors, fans, and pumps. But it will likely be more valuable in applications that require the linking of multiple motors, such as textile production, and in applications that require tight control over torque, such as cranes, elevators, and centrifuges.

  12. Thermal and vibration dynamic analysis of an induction motor using optical fiber Bragg gratings

    NASA Astrophysics Data System (ADS)

    Sousa, Kleiton d. M.; Dreyer, Uilian J.; Martelli, Cicero; Cardozo da Silva, Jean Carlos

    2015-09-01

    In this paper it is presented the results of temperature and vibration measurements in a Three-phase Induction Motor (TIM) running at no-load condition. Vibration and temperature analysis are the most successful techniques used for condition monitoring of induction motors. The vibration is measured using two FBGs installed inside of the motor between two subsequent stator teeth. The motor spectrum of vibration when power is at 60 Hz presents the frequencies 60 Hz, 120 Hz, 180 Hz, and 240 Hz as theoretically expected. For the temperature measurement two FBGs are encapsulated in an alumina tube fixed along the stator. The results show 0.9°C difference between the two FBG caused by the motor ventilation nearer of one FBG. These measurements can be used to determine TIM parameters and still be predictive maintenance tool.

  13. Reluctance network analysis of an orthogonal-core type parametric induction motor

    SciTech Connect

    Tajima, Katsubumi; Sato, Kohei; Komukai, Toshihiko; Ichinokura, Osamu

    1999-09-01

    In this paper, an analytical method of an orthogonal-core type parametric induction motor is proposed, based on a reluctance network model of the stator. The model is derived by a similar technique applied to an orthogonal-core transformer. Using this model the parametric oscillation characteristic of the motor, without a rotor, is computed. The simulation results agree well with the experiments. It is obvious that the analytical model of the stator presented here is proper for analysis of the motor and that, by use of this model and suitable analytical model of the rotor, the motor characteristics can be analyzed.

  14. Dynamic model tracking design for low inertia, high speed permanent magnet ac motors.

    PubMed

    Stewart, P; Kadirkamanathan, V

    2004-01-01

    Permanent magnet ac (PMAC) motors have existed in various configurations for many years. The advent of rare-earth magnets and their associated highly elevated levels of magnetic flux makes the permanent magnet motor attractive for many high performance applications from computer disk drives to all electric racing cars. The use of batteries as a prime storage element carries a cost penalty in terms of the unladen weight of the vehicle. Minimizing this cost function requires the minimum electric motor size and weight to be specified, while still retaining acceptable levels of output torque. This tradeoff can be achieved by applying a technique known as flux weakening which will be investigated in this paper. The technique allows the speed range of a PMAC motor to be greatly increased, giving a constant power range of more than 4:1. A dynamic model reference controller is presented which has advantages in ease of implementation, and is particularly suited to dynamic low inertia applications such as clutchless gear changing in high performance electric vehicles. The benefits of this approach are to maximize the torque speed envelope of the motor, particularly advantageous when considering low inertia operation. The controller is examined experimentally, confirming the predicted performance. PMID:15000141

  15. Steady-state, lumped-parameter model for capacitor-run, single-phase induction motors

    SciTech Connect

    Umans, S.D.

    1996-01-01

    This paper documents a technique for deriving a steady-state, lumped-parameter model for capacitor-run, single-phase induction motors. The objective of this model is to predict motor performance parameters such as torque, loss distribution, and efficiency as a function of applied voltage and motor speed as well as the temperatures of the stator windings and of the rotor. The model includes representations of both the main and auxiliary windings (including arbitrary external impedances) and also the effects of core and rotational losses. The technique can be easily implemented and the resultant model can be used in a wide variety of analyses to investigate motor performance as a function of load, speed, and winding and rotor temperatures. The technique is based upon a coupled-circuit representation of the induction motor. A notable feature of the model is the technique used for representing core loss. In equivalent-circuit representations of transformers and induction motors, core loss is typically represented by a core-loss resistance in shunt with the magnetizing inductance. In order to maintain the coupled-circuit viewpoint adopted in this paper, this technique was modified slightly; core loss is represented by a set of core-loss resistances connected to the ``secondaries`` of a set of windings which perfectly couple to the air-gap flux of the motor. An example of the technique is presented based upon a 3.5 kW, single-phase, capacitor-run motor and the validity of the technique is demonstrated by comparing predicted and measured motor performance.

  16. Calculation and Measurement of Coil Inductance Profile in Tubular Linear Reluctance Motor and its Validation by Three Dimensional FEM

    NASA Astrophysics Data System (ADS)

    Mosallanejad, Ali; Shoulaie, Abbas

    2011-07-01

    This paper reports a study of coil inductance profile in all positions of plunger in tubular linear reluctance motors (TLRMs) with open type magnetic circuits. In this paper, maximum inductance calculation methods in winding of tubular linear reluctance motors are described based on energy method. Furthermore, in order to calculate the maximum inductance, equivalent permeability is measured. Electromagnetic finite-element analysis for simulation and calculation of coil inductance in this motor is used. Simulation results of coil inductance calculation using 3-D FEM with coil current excitation is compared to theoretical and experimental results. The comparison yields a good agreement.

  17. A thermal network model for induction motors of hermetic reciprocating compressors

    NASA Astrophysics Data System (ADS)

    Dutra, T.; Deschamps, C. J.

    2015-08-01

    This paper describes a simulation model for small reciprocating compressors with emphasis on the electrical motor modelling. Heat transfer is solved through algebraic equations derived from lumped thermal energy balances applied to the compressor components. Thermal conductances between the motor components are characterized via a thermal network model. The single-phase induction motor is modelled via an equivalent circuit, allowing predictions for the motor performance and distributed losses. The predicted temperature distribution is used to evaluate the stator and rotor windings resistances. The thermal and electric models are solved in a coupled manner with a model for the compression cycle. Predictions of temperature distribution, motor efficiency, as well as isentropic and volumetric efficiencies, are compared with experimental data at different operating conditions. The model is then applied to analyse the motor temperature as a function of input voltage and stator wire diameter.

  18. Implementation of DSP Based Cost Effective Inverter Fed Induction Motor Drive with VisSim

    NASA Astrophysics Data System (ADS)

    Mohanty, Nalin K.; Muthu, Ranganath

    2012-03-01

    The implementation of a Digital Signal Processor (DSP) based high-performance cost effective fed Induction Motor drive with VisSim/Embedded Controls Developer (ECD) is presented in this paper. In the experimental work VisSim/ECD software automatically converts the in built block diagram to C code and compiles, links, and downloads the code to DSP processor TMS320F2812. The DSP processor generates the required PWM to a cost effective ie four switch 3-phase (FSTPI) inverter. The power circuit of FSTPI fed drive system consists of an IGBT based FSTPI bridge inverter module feeding to a 5 hp three-phase squirrel cage induction motor. In this work the speed of induction motor output is shown by the GUI of VisSim/ECD and SPWM pulses, line voltages and line current output curves are shown using digital storage oscilloscope to demonstrate the feasibility of the system.

  19. Identifying three-phase induction motor faults using artificial neural networks

    PubMed

    Kolla; Varatharasa

    2000-01-01

    This paper presents an artificial neural network (ANN) based technique to identify faults in a three-phase induction motor. The main types of faults considered are overload, single phasing, unbalanced supply voltage, locked rotor, ground fault, over-voltage and under-voltage. Three-phase currents and voltages from the induction motor are used in the proposed approach. A feedforward layered neural network structure is used. The network is trained using the backpropagation algorithm. The trained network is tested with simulated fault current and voltage data. Fault detection is attempted in the no fault to fault transition period. Off-line testing results on a 3 HP induction motor model show that the proposed ANN based method is effective in identifying various types of faults. PMID:11106295

  20. Research on Direct Torque Control of Induction Motor Based on TMS320LF2407A

    NASA Astrophysics Data System (ADS)

    Lufei, Xu; Guangqun, Nan

    The direct torque control of Induction Motor is one of the high performance control system, which was proposed after the vector control scheme. During the recent 20 years, It has been developed rapidly for its concise system scheme, excellent dynamic and static performances. DTC system directly controls the electromagnetic torque and stator flux, using the analyzing method of space vector and stator flux orientation. This paper establishes the mathematical model of direct torque control (DTC) system of induction motor, and direct torque control (DTC) scheme of induction motor based on TMS320LF2407A is introduced. The control scheme gets the switch control signal of inverter with the space voltage vector modulation technology. Finally the approach has been implemented on DSP in a 1.1 kW drive. The results show that the DTC with SVPWM has many merits such as simple realization, good running performance and high voltage utilization ratio.

  1. Simple and Robust Indirect Thrust Control for Positioning of Linear Induction Motors

    NASA Astrophysics Data System (ADS)

    Martínez-Iturralde, Miguel; Martínez, Gonzalo; Castelli, Marcelo; Rico, Andrés García; Flórez, Julián

    Dealing with position control of Linear Induction Motors (LIM), most strategies in bibliography are based on Secondary Flux Oriented Control (SFOC) and Direct Thrust Control (DTC). However, SFOC of linear induction motors needs complex identification methods to compensate parameter variation during operation, mainly due to local heating and end-effects. On the other hand, DTC based methods for LIMs present thrust ripple and have problems at low and zero speeds. In this paper, a new Indirect Thrust Control (ITC) based strategy for position control of linear induction motors that makes up for these drawbacks is presented. The position control loop design methodology and the method for automatic adjustment of compensators are described. Experimental results are presented to evaluate the performance and sensitivity of the control strategy. Finally, some conclusions are drawn about the applicability of the new algorithm that demonstrate the main advantages versus SFOC and DTC.

  2. Theoretical analysis of a YBCO squirrel-cage type induction motor based on an equivalent circuit

    NASA Astrophysics Data System (ADS)

    Morita, G.; Nakamura, T.; Muta, I.

    2006-06-01

    A HTS induction motor, with a HTS squirrel-cage rotor, is analysed using an electrical equivalent circuit. The squirrel-cage winding in the rotor consists of rotor bars and end rings, and both are considered to be made of YBCO film conductors. A wide range of electric field versus current density in YBCO film is formulated based on the Weibull function, and analysed as a non-linear resistance in the equivalent circuit. It is shown that starting and accelerating torques of the HTS induction motor are improved drastically compared to those of a conventional induction motor. Furthermore, large synchronous torque can also be realized by trapping the magnetic flux in the rotor circuit because of the persistent current mode.

  3. Diagnosis of Stator-Winding-Turn Faults of Induction Motor by Direct Detection of Negative-Sequence Currents

    NASA Astrophysics Data System (ADS)

    Kato, Toshiji; Inoue, Kaoru; Yoshida, Keisuke

    In an AC motor, the quick detection of an initially small fault is important for preventing any consequent large fault. Various detection approaches have been proposed in previous papers, for example, by the Park vector (PV), AI techniques, wavelet analysis, and negative-sequence analysis. This paper proposes a method for diagnosing the stator-winding faults of an induction motor by the direct detection of its negative-sequence current. Before starting the diagnosis, the asymmetry admittances for the considered fault cases are obtained by analysis or simulation. The amplitude and phase of the positive-sequence voltage, Vp, and of the positive-sequence current, Ip, are extracted from the voltage PV and current PV, respectively. The amplitude and phase of the negative-sequence, In, are extracted from the residue. The asymmetry admittance, Ya, is calculated from In and Vp. When the positive-sequence admittance is known, Ya can also be calculated from Yp, Ip, and In. These steps are repeated for each sample time and the motor condition is diagnosed according to the variations in the Ya values. The simulation and experimental results are also shown and the proposed method is investigated and validated.

  4. Evaluation of half wave induction motor drive for use in passenger vehicles

    NASA Technical Reports Server (NTRS)

    Hoft, R. G.; Kawamura, A.; Goodarzi, A.; Yang, G. Q.; Erickson, C. L.

    1985-01-01

    Research performed at the University of Missouri-Columbia to devise and design a lower cost inverter induction motor drive for electrical propulsion of passenger vehicles is described. A two phase inverter motor system is recommended. The new design is predicted to provide comparable vehicle performance, improved reliability and a cost advantage for a high production vehicle, decreased total rating of the power semiconductor switches, and a somewhat simpler control hardware compared to the conventional three phase bridge inverter motor drive system. The major disadvantages of the two phase inverter motor drive are that it is larger and more expensive than a three phase machine, the design of snubbers for the power leakage inductances produce higher transient voltages, and the torque pulsations are relatively large because of the necessity to limit the inverter switching frequency to achieve high efficiency.

  5. Heat transfer enhancement in the unfinned frame of an externally cooled induction motor

    SciTech Connect

    Jeon, C.S.; Yoon, M.K.; Kauh, S.K.

    2000-02-01

    This article describes an experimental investigation to study the effect of guide vanes on the heat transfer coefficient over the unfinned frame of an externally cooled induction motor. Guide vanes with various heights and spacings have been tested. In general, the guide vanes modify the air flow over the frame, hence increasing the heat transfer coefficient. An optimum heat transfer case is found, for which the average heat transfer coefficient is 70% higher than for the case without guide vanes. The velocity distributions of the air flow are measured for comparison with the heat transfer coefficient fields. The location of the terminal box is optimized, resulting in a 1 C drop in the average temperature rise of the coil motor. Finally, the results of this research are applied to a real induction motor and its average coil temperature becomes 9 C lower than that of a commercial motor.

  6. Continuous Path Tracking Control by Considering Voltage Saturation and Current Saturation for AC Servo Motor

    NASA Astrophysics Data System (ADS)

    Sazawa, Masaki; Ohishi, Kiyoshi; Katsura, Seiichiro

    Continuous path tracking control is an important technology for the position control system such as factory automation field. Particulaly, large torque is required for continuous path tracking control at its start position and its goal position. Each AC servo motor of continuous path tracking control have limitation of current and voltage. Therefore, in controlling a multi-degree-of-freedom continuous path tracking control system, even if only the motor torque of one axis has the current limitation, the actual position response is not often equal to the desired trajectory reference. In order to overcome these problems, this paper proposes a new continuous path tracking control algorithm by considering both the saturation of voltage and current. The proposed method assures the coordinated motion by considering the saturation of voltage and current. The effectiveness of the proposed method is confirmed by the experimental results in this paper.

  7. Variable speed induction motor operation from a 20-kHz power bus

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1989-01-01

    Induction motors are recognized for their simple rugged construction to date, however, their application to variable speed or servo drives has been hampered by limitations on their control. Induction motor drives tend to be complex and to display troublesome low speed characteristics due in part to nonsinusoidal driving voltages. A technique was developed which involves direct synthesis of sinusoidal driving voltages from a high frequency power bus and independent control of frequency and voltages. Separation offrequency and voltage allows independent control of rotor and stator flux, full four-quadrant operation, and instantaneous torque control. Recent test results, current status of the technology, and proposed aerospace applications will be discussed.

  8. FPGA-based entropy neural processor for online detection of multiple combined faults on induction motors

    NASA Astrophysics Data System (ADS)

    Cabal-Yepez, E.; Valtierra-Rodriguez, M.; Romero-Troncoso, R. J.; Garcia-Perez, A.; Osornio-Rios, R. A.; Miranda-Vidales, H.; Alvarez-Salas, R.

    2012-07-01

    For industry, a faulty induction motor signifies production reduction and cost increase. Real-world induction motors can have one or more faults present at the same time that can mislead to a wrong decision about its operational condition. The detection of multiple combined faults is a demanding task, difficult to accomplish even with computing intensive techniques. This work introduces information entropy and artificial neural networks for detecting multiple combined faults by analyzing the 3-axis startup vibration signals of the rotating machine. A field programmable gate array implementation is developed for automatic online detection of single and combined faults in real time.

  9. Variable speed induction motor operation from a 20-kHz power bus

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.

    1989-01-01

    Induction motors are recognized for their simple rugged construction. To date, however, their application to variable speed or servo drives was hampered by limitations on their control. Induction motor drives tend to be complex and to display troublesome low speed characteristics due in part to nonsinusoidal driving voltages. A technique was developed which involves direct synthesis of sinusoidal driving voltages from a high frequency power bus and independent control of frequency and voltages. Separation of frequency and voltage allows independent control of rotor and stator flux, full four quadrant operation, and instantaneous torque control. Recent test results, current status of the technology, and proposed aerospace applications will be discussed.

  10. A high-speed induction motor making use of the third harmonic of the magnetic flux

    NASA Astrophysics Data System (ADS)

    Goleman, Ryszard

    1994-05-01

    This paper indicates some possibilities of construction of high-speed induction motors taking advantage of the magnetic flux third harmonic due to a process of magnetization of nonlinear magnetic circuits. Configurations of magnetic frequency triplers, which can be used as basic stator structures and generate a distorted flux, are presented. The paper also describes an experimental high-speed induction motor supplied from a single-phase source via a magnetic frequency tripler that make possible to obtain a rotating field having a synchronous speed equal to 9000 rpm at a supply voltage angular frequency of 314 rd.

  11. An Experimental Research on Vector Control of Induction Motor Based on Simple Model

    NASA Astrophysics Data System (ADS)

    Zhang, Yinhai; Ge, Jinfa; Liu, Weixia; Wang, Qin

    Given the heavy computation, easy saturation and cumulate errors of conventional direct vector control, the vector control of induction motor based on simple model is studied and the detailed scheme is described on the basis of the decomposing and approximating the rotor flux. Because of the direct closed-loop control of the magnetizing current and the torque current and the complex current regulator is completed by PI regulator, so the direct vector control of induction motor is simplified. The experimental results show that the proposed method is effective in decreasing the dynamic disturbance and has the advantages of the simplicity of the code program, rare saturation and shocks.

  12. Fault diagnosis in induction motors using radial magnetic field measurement with an antenna

    NASA Astrophysics Data System (ADS)

    Belkhayat, D.; Romary, R.; El Adnani, M.; Corton, R.; Brudny, J. F.

    2003-09-01

    In this paper the emf induced in a search coil is measured in order to detect faults in an induction motor. Anomalous operations caused by a broken rotor bar or a faulty stator cutting phase are analysed. Starting from a theoretical analysis of the radial field spectrum associated with these faults, the measurement of the corresponding emf in the search antenna is examined. The saturation and harmonic components of the permeance produced by the slotting effect are taken into account. Their interactions are analysed, allowing the identification of the frequencies which are of interest for the detection of stator cutting phase faults in a working induction motor.

  13. Variable-Speed Induction Motor Drives for Aircraft Environmental Control Compressors

    NASA Technical Reports Server (NTRS)

    Mildice, J. W.; Hansen, I. G.; Schreiner, K. E.; Roth, M. E.

    1996-01-01

    New, more-efficient designs for aircraft jet engines are not capable of supplying the large quantities of bleed air necessary to provide pressurization and air conditioning for the environmental control systems (ECS) of the next generation of large passenger aircraft. System analysis and engineering have determined that electrically-driven ECS can help to maintain the improved fuel efficiencies; and electronic controllers and induction motors are now being developed in a NASA/NPD SBIR Program to drive both types of ECS compressors. Previous variable-speed induction motor/controller system developments and publications have primarily focused on field-oriented control, with large transient reserve power, for maximum acceleration and optimum response in actuator and robotics systems. The application area addressed herein is characterized by slowly-changing inputs and outputs, small reserve power capability for acceleration, and optimization for maximum efficiency. This paper therefore focuses on the differences between this case and the optimum response case, and shows the development of this new motor/controller approach. It starts with the creation of a new set of controller requirements. In response to those requirements, new control algorithms are being developed and implemented in an embedded computer, which is integrated into the motor controller closed loop. Buffered logic outputs are used to drive the power switches in a resonant-technology, power processor/motor-controller, at switching/resonant frequencies high enough to support efficient high-frequency induction motor operation at speeds up to 50,000-RPA

  14. Dual-circuit segmented rail phased induction motor

    DOEpatents

    Marder, Barry M.; Cowan, Jr., Maynard

    2002-01-01

    An improved linear motor utilizes two circuits, rather that one circuit and an opposed plate, to gain efficiency. The powered circuit is a flat conductive coil. The opposed segmented rail circuit is either a plurality of similar conductive coils that are shorted, or a plurality of ladders formed of opposed conductive bars connected by a plurality of spaced conductors. In each embodiment, the conductors are preferably cables formed from a plurality of intertwined insulated wires to carry current evenly.

  15. Smart Sensor for Online Detection of Multiple-Combined Faults in VSD-Fed Induction Motors

    PubMed Central

    Garcia-Ramirez, Armando G.; Osornio-Rios, Roque A.; Granados-Lieberman, David; Garcia-Perez, Arturo; Romero-Troncoso, Rene J.

    2012-01-01

    Induction motors fed through variable speed drives (VSD) are widely used in different industrial processes. Nowadays, the industry demands the integration of smart sensors to improve the fault detection in order to reduce cost, maintenance and power consumption. Induction motors can develop one or more faults at the same time that can be produce severe damages. The combined fault identification in induction motors is a demanding task, but it has been rarely considered in spite of being a common situation, because it is difficult to identify two or more faults simultaneously. This work presents a smart sensor for online detection of simple and multiple-combined faults in induction motors fed through a VSD in a wide frequency range covering low frequencies from 3 Hz and high frequencies up to 60 Hz based on a primary sensor being a commercially available current clamp or a hall-effect sensor. The proposed smart sensor implements a methodology based on the fast Fourier transform (FFT), RMS calculation and artificial neural networks (ANN), which are processed online using digital hardware signal processing based on field programmable gate array (FPGA).

  16. Singular value decomposition based feature extraction approaches for classifying faults of induction motors

    NASA Astrophysics Data System (ADS)

    Kang, Myeongsu; Kim, Jong-Myon

    2013-12-01

    This paper proposes singular value decomposition (SVD)-based feature extraction methods for fault classification of an induction motor: a short-time energy (STE) plus SVD technique in the time-domain analysis, and a discrete cosine transform (DCT) plus SVD technique in the frequency-domain analysis. To early identify induction motor faults, the extracted features are utilized as the inputs of multi-layer support vector machines (MLSVMs). Since SVMs perform well with the radial basis function (RBF) kernel for appropriately categorizing the faults of the induction motor, it is important to explore the impact of the σ values for the RBF kernel, which affects the classification accuracy. Likewise, this paper quantitatively evaluates the classification accuracy with different numbers of features, because the number of features affects the classification accuracy. According to the experimental results, although SVD-based features are effective for a noiseless environment, the STE plus SVD feature extraction approach is more effective with and without sensor noise in terms of the classification accuracy than the DCT plus SVD feature extraction approach. To demonstrate the improved classification of the proposed approach for identifying faults of the induction motor, the proposed SVD based feature extraction approach is compared with other state-of-the art methods and yields higher classification accuracies for both noiseless and noisy environments than conventional approaches.

  17. Concept for sleeve induction motor with 1-msec mechanical time constant

    NASA Technical Reports Server (NTRS)

    Wiegand, D. E.

    1968-01-01

    Conductive sleeve induction motor having a 1-msec mechanical time constant is used with solid-state devices to control all-electric servo power systems. The servomotor rotor inertia is small compared to the maximum force rating of the servo motion, permitting high no-load acceleration.

  18. A Comparison of Different Techniques for Induction Motor Rotor Fault Diagnosis

    NASA Astrophysics Data System (ADS)

    Alwodai, A.; Gu, F.; Ball, A. D.

    2012-05-01

    The problem of failures in induction motors is a large concern due to its significant influence over industrial production. Therefore a large number of detection techniques were presented to avoid this problem. This paper presents the comparison results of induction motor rotor fault detection using three methods: motor current signature analysis (MCSA), surface vibration (SV), and instantaneous angular speed (IAS). These three measurements were performed under different loads with three rotor conditions: baseline, one rotor bar broken and two rotor bar broken. The faults can be detected and diagnosed based on the amplitude difference of the characteristic frequency components of power spectrum. However IAS may be the best technique because it gives the clearest spectrum representation in which the largest amplitude change is observed due to the faults.

  19. Modeling and Simulating of Single Side Short Stator Linear Induction Motor with the End Effect

    NASA Astrophysics Data System (ADS)

    Hamzehbahmani, Hamed

    2011-09-01

    Linear induction motors are under development for a variety of demanding applications including high speed ground transportation and specific industrial applications. These applications require machines that can produce large forces, operate at high speeds, and can be controlled precisely to meet performance requirements. The design and implementation of these systems require fast and accurate techniques for performing system simulation and control system design. In this paper, a mathematical model for a single side short stator linear induction motor with a consideration of the end effects is presented; and to study the dynamic performance of this linear motor, MATLAB/SIMULINK based simulations are carried out, and finally, the experimental results are compared to simulation results.

  20. An innovative direct self-control scheme for induction motor drives

    SciTech Connect

    Bonanno, F.; Consoli, A.; Raciti, A.; Testa, A.

    1997-09-01

    The paper presents a new direct self-control (DSC) scheme for induction motor drives using the stator voltage third harmonic component in order to estimate the air-gap flux and the torque as well as to synchronize the supply voltage vector. Compared to previous DSC schemes the new one is independent from any motor parameter variation, specifically on stator resistance thus showing better performances at low speeds. The paper starts with a quick review on standard DSC main features pointing out the influence of stator resistance variations on the flux and torque control. The new DSC scheme is then introduced and evaluated by simulations and experimental tests on a 1.5-kW induction motor drive.

  1. A Fast Induction Motor Speed Estimation based on Hybrid Particle Swarm Optimization (HPSO)

    NASA Astrophysics Data System (ADS)

    Aryza, Solly; Abdallah, Ahmed N.; Khalidin, Zulkeflee bin; Lubis, Zulkarnain; Jie, Ma

    Intelligent control and estimation of power electronic systems by fuzzy logic and neural network techniques with fast torque and flux show tremendous promise in future. This paper proposed the application of Hybrid Particle Swarm Optimization (HPSO) for losses and operating cost minimization control in the induction motor drives. The main advantages of the proposed technique are; its simple structure and its straightforward maximization of induction motor efficiency and its operating cost for a given load torque. As will be demonstrated, Hybrid Particle Swarm Optimization (HPSO) is so efficient in finding the optimum operating machine's flux level. The results demonstrate the good quality and robustness in the system dynamic response and reduction in the steady-state and transient motor ripple torque.

  2. Speed and efficiency control of an induction motor with input-output linearization

    SciTech Connect

    Wang, W.J.; Wang, C.C.

    1999-09-01

    A combination of a composite adaptive speed controller and an explicit efficiency control algorithm is proposed to control the speed and power efficiency of the induction motor in this paper. First, the input-output linearization method is used to dynamically decouple the motor speed and rotor flux. Then, a composite adaptive control algorithm is designed to control the speed of the induction motor. At steady-state light-load conditions, the magnetizing current command is adjusted on the basis of the product of magnetizing current command and torque current command such that the steady-state power loss is minimum. A PC-based experimental drive system has been implemented, and some experimental results are provided to demonstrate the effectiveness of the presented approach.

  3. A current monitoring system for diagnosing electrical failures in induction motors

    NASA Astrophysics Data System (ADS)

    Acosta, G. G.; Verucchi, C. J.; Gelso, E. R.

    2006-05-01

    Induction motors are critical components in industrial processes. A motor failure may yield an unexpected interruption at the industrial plant, with consequences in costs, product quality, and safety. Many of these faulty situations in three phase induction motors have an electrical reason. Among different detection approaches proposed in the literature, those based on stator current monitoring are advantageous due to its non-invasive properties. One of these techniques resorts to spectrum analysis of machine line current. Another non-invasive technique is the Extended Park's Vector Approach, which allows the detection of inter-turn short circuits in the stator winding. This article presents the development of an on-line current monitoring system that uses both techniques for fault detection and diagnosis in the stator and in the rotor. Based on experimental observations and on the knowledge of the electrical machine, a knowledge-based system was constructed in order to carry out the diagnosis task from these estimated data.

  4. A novel indicator of stator winding inter-turn fault in induction motor using infrared thermal imaging

    NASA Astrophysics Data System (ADS)

    Eftekhari, M.; Moallem, M.; Sadri, S.; Hsieh, Min-Fu

    2013-11-01

    In this paper, a novel online and non-destructive algorithm is proposed to detect inter-turn short circuit faults in the stator windings of an induction motor. This fault detection algorithm is based on the features extracted from infrared images taken from the hottest region of the motor surface. Feature extraction method from infrared thermal images has been developed based on histogram of temperature profile, correlation between fault severity and the hottest region on the motor body, and comparison with healthy motor features. Experiments are conducted to demonstrate the effectiveness of the proposed method using a 2-hp induction motor.

  5. Flux-Based Deadbeat Control of Induction-Motor Torque

    NASA Technical Reports Server (NTRS)

    Kenny, Barbara H.; Lorenz, Robert D.

    2003-01-01

    An improved method and prior methods of deadbeat direct torque control involve the use of pulse-width modulation (PWM) of applied voltages. The prior methods are based on the use of stator flux and stator current as state variables, leading to mathematical solutions of control equations in forms that do not lend themselves to clear visualization of solution spaces. In contrast, the use of rotor and stator fluxes as the state variables in the present improved method lends itself to graphical representations that aid in understanding possible solutions under various operating conditions. In addition, the present improved method incorporates the superposition of high-frequency carrier signals for use in a motor-self-sensing technique for estimating the rotor shaft angle at any speed (including low or even zero speed) without need for additional shaft-angle-measuring sensors.

  6. A current-source inverter fed induction motor drive system with reduced losses

    SciTech Connect

    Espinoza, J.R.; Joos, G.

    1995-12-31

    Standard low and medium induction power motor drives are based on the PWM voltage source inverter (VSI) fed from a diode rectifier. The dual topology, based on the current source inverter/rectifier structure is used in medium and high power applications. This paper addresses some of the drawbacks of this approach compared to the voltage source approach. The proposed drive features: (a) an on-line operated PWM inverter, using instantaneous output capacitor voltage control based on space vector modulation; (b) a line-synchronized PWM rectifier, with dc bus current control; (c) an additional inverter modulation index control loop, ensuring a constant inverter modulation index. The resulting advantages include: (a) ruggedness and inherent continuous regeneration capability; (b) near unity global input power factor; (c) reduced motor voltage distortion; (d) reduced dc bus inductor and switch conduction losses; (e) fast motor dynamic response; (f) elimination of motor circuit resonances. Simulated and experimental results based on a DSP implementation are given.

  7. Disk-shaped superconducting rotor for an axial flux induction motor

    NASA Astrophysics Data System (ADS)

    Álvarez, A.; Suárez, P.; Cáceres, D.; Granados, X.; Pérez, B.; Ceballos, J. M.

    2003-11-01

    Most work on bulk-based superconducting electrical motors has been done with superconducting materials in the rotor only, due to the difficulty in machining the material into the conventional coil shape. As part of the design of a superconducting induction motor with superconductors in both rotor and stator, we made a disk-shaped rotor from the same YBCO bulks that we use to fabricate ceramic coils in constructing a modular stator for a biphasic axial flux motor, and studied this rotor’s working behaviour. To this end we constructed a system to simulate the working environment of a YBCO disk within the motor, and measured the magnetic field in the disk and the speed-torque characteristic.

  8. Induction Motor Drive System Based on Linear Active Disturbance Rejection Controller

    NASA Astrophysics Data System (ADS)

    Liu, Liying; Zhang, Yongli; Yao, Qingmei

    It is difficult to establish an exact mathematical model for the induction motor and the robustness is poor of the vector control system using PI regulator. This paper adopts the linear active disturbance rejection controller (LADRC) to control inductor motor. LADRC doesn't need the exact mathematical model of motor and it can not only estimate but also compensate the general disturbance that includes the coupling items in model of motor and parameters perturbations by linear extended state observer (LESO), so the rotor flux and torque fully decouple. As a result, the performance is improved. To prove the above control scheme, the proposed control system has been simulated in MATLAB/SIMULINK, and the comparison was made with PID. Simulation results show that LADRC' has better performance and robustness than PID.

  9. Inductance Calculation and New Modeling of a Synchronous Reluctance Motor Using Flux Linkages

    NASA Astrophysics Data System (ADS)

    Nashiki, Masayuki; Inoue, Yoshimitu; Kawai, Youichi; Okuma, Shigeru

    New modeling of a synchronous reluctance motor SynRM which has non-linear magnetic characteristics is proposed. And a control method of the SynRM using the new model is developed. The new model is based on the inductance data table or the flux linkage data table which is calculated with the flux linkages of the SynRM at each current (id, iq). Detailed calculation method of the inductances is described. The calculated torque TA with the inductance data table is compared with the torque Tfem which is calculated by FEM and the difference is less than 5% at the rated torque. Therefore the accuracy of the new model is certified. And the same method is applicable to an interior permanent magnet synchronous motor IPMSM. The high performance motor control is realized. The exact current commands (id, iq), the exact voltage feed-forward commands (FFd, FFq) and the adaptive current loop gain (Gd, Gq) are obtained using the FEM data of the motor.

  10. Electric vehicle motors and controllers

    NASA Technical Reports Server (NTRS)

    Secunde, R. R.

    1981-01-01

    Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

  11. Fault analysis for condition monitoring of induction motors

    NASA Astrophysics Data System (ADS)

    Nandi, Subhasis

    Recently, research has picked up a fervent pace in the area of fault diagnosis of electrical machines. Like adjustable speed drives, fault prognosis has become almost indispensable. The manufacturers of these drives are now keen to include diagnostic features in the software to decrease machine down time and improve salability. Prodigious improvement in signal processing hardware and software has made this possible. Primarily, these techniques depend upon locating specific harmonic components in the line current, also known as motor current signature analysis (MCSA). These harmonic components are usually different for different types of faults. However, with multiple faults or different varieties of drive schemes, MCSA can become an onerous task as different types of faults and time harmonics may end up generating similar signatures. Thus, other signals such as speed, torque, noise, vibration, etc., are also explored for their frequency contents. Sometimes, altogether different techniques such as thermal measurements, chemical analysis, etc., are also employed to find out the nature and the degree of the fault. It is indeed evident that this area is vast in scope. Going by the present trend, human involvement in the actual fault detection decision making is slowly being replaced by automated tools such as expert systems, neural networks, fuzzy logic based systems; to name a few. However, this cannot be achieved without detailed fault analysis and subsequent recognition of the fault pattern. Keeping this in mind, simulation studies of the broken bar and eccentricity related faults using MCSA have been taken up. Also, a common theoretical basis for the different types (static, dynamic and mixed) of eccentricity related faults which give different signatures for different pole and rotor bar combinations has been developed. This will be of great importance both from fault diagnosis as well as sensorless drive applications' viewpoint. Finally, the insight gained from

  12. Speed Sensorless Induction Motor Drives for Electrical Actuators: Schemes, Trends and Tradeoffs

    NASA Technical Reports Server (NTRS)

    Elbuluk, Malik E.; Kankam, M. David

    1997-01-01

    For a decade, induction motor drive-based electrical actuators have been under investigation as potential replacement for the conventional hydraulic and pneumatic actuators in aircraft. Advantages of electric actuator include lower weight and size, reduced maintenance and operating costs, improved safety due to the elimination of hazardous fluids and high pressure hydraulic and pneumatic actuators, and increased efficiency. Recently, the emphasis of research on induction motor drives has been on sensorless vector control which eliminates flux and speed sensors mounted on the motor. Also, the development of effective speed and flux estimators has allowed good rotor flux-oriented (RFO) performance at all speeds except those close to zero. Sensorless control has improved the motor performance, compared to the Volts/Hertz (or constant flux) controls. This report evaluates documented schemes for speed sensorless drives, and discusses the trends and tradeoffs involved in selecting a particular scheme. These schemes combine the attributes of the direct and indirect field-oriented control (FOC) or use model adaptive reference systems (MRAS) with a speed-dependent current model for flux estimation which tracks the voltage model-based flux estimator. Many factors are important in comparing the effectiveness of a speed sensorless scheme. Among them are the wide speed range capability, motor parameter insensitivity and noise reduction. Although a number of schemes have been proposed for solving the speed estimation, zero-speed FOC with robustness against parameter variations still remains an area of research for speed sensorless control.

  13. Modeling and damping of high-frequency leakage currents in PWM inverter-fed AC motor drive systems

    SciTech Connect

    Ogasawara, Satoshi; Akagi, Hirofumi

    1995-12-31

    This paper presents an equivalent circuit for high-frequency leakage currents in PWM inverter-fed ac motors, which forms a series resonant circuit. The analysis based on the equivalent circuit leads to such a conclusion that the connection of a conventional common-mode choke or reactor in series between the ac terminals of a PWM inverter and those of an ac motor is not effective to reduce the rms and average values of the leakage current, but effective to reduce the peak value. Furthermore, this paper proposes a common-mode transformer which is different in damping principle from the conventional common-mode choke. It is shown theoretically and experimentally that the common-mode transformer is able to reduce the rms value of the leakage current to 25%, where the core used in the common-mode transformer is smaller than that of the conventional common-mode choke.

  14. Evaluation of induction motor performance using an electronic power factor controller

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The concept of reducing the losses in an induction motor by electronically controlling the time interval between the zero crossing of the applied voltage and the zero crossing of the armature current was evaluated. The effect on power losses and power factor of reducing the applied sinusoidal voltages below the rated value was investigated experimentally. The reduction in power losses was measured using an electronic controller designed and built at MSFC. Modifications to the MSFC controller are described as well as a manually controlled electronic device which does not require that the motor be wye connected and the neutral available. Possible energy savings are examined.

  15. Flywheel induction motor-generator for magnet power supply in small fusion device.

    PubMed

    Hatakeyma, S; Yoshino, F; Tsutsui, H; Tsuji-Iio, S

    2016-04-01

    A flywheel motor-generator (MG) for the toroidal field (TF) coils of a small fusion device was developed which utilizes a commercially available squirrel-cage induction motor. Advantages of the MG are comparably-long duration, quick power response, and easy implementation of power control compared with conventional capacitor-type power supply. A 55-kW MG was fabricated, and TF coils of a small fusion device were energized. The duration of the current flat-top was extended to 1 s which is much longer than those of conventional small devices (around 10-100 ms). PMID:27131676

  16. Flywheel induction motor-generator for magnet power supply in small fusion device

    NASA Astrophysics Data System (ADS)

    Hatakeyma, S.; Yoshino, F.; Tsutsui, H.; Tsuji-Iio, S.

    2016-04-01

    A flywheel motor-generator (MG) for the toroidal field (TF) coils of a small fusion device was developed which utilizes a commercially available squirrel-cage induction motor. Advantages of the MG are comparably-long duration, quick power response, and easy implementation of power control compared with conventional capacitor-type power supply. A 55-kW MG was fabricated, and TF coils of a small fusion device were energized. The duration of the current flat-top was extended to 1 s which is much longer than those of conventional small devices (around 10-100 ms).

  17. Linearization Method for Starting Control of Speed-Sensorless Vector-Controlled Induction Motors

    NASA Astrophysics Data System (ADS)

    Fujinami, Kazuki; Kondo, Keiichiro

    A linearization method is proposed for controlling the start-up operation of a rotating induction motor. The dynamics of this motor are deteriorated when the starting operation is carried out at high frequencies. In this method, the characteristics of the method are analyzed to reveal that the aforementioned problem is caused by the low equivalent gain of the induced voltage during the rotor flux establishment. A method to compensate for the angle of the rotor-flux-induced voltage vector is proposed to overcome this problem. The proposed method is experimentally verified by a test set, and the influence of changes in the rotor resistance is analyzed.

  18. Design single-motor AC drive for energy savings in centrifugal applications

    SciTech Connect

    Not Available

    1982-06-01

    This article is an evaluation of a single- motor with AC drive that saves energy with increased efficiency and reliability in a wide variety of pump, fan, compressor, and other centrifugal applications. Drives deliver adjustable speed for adjustable flow and will satisfy a number of particular objectives. A principal benefit of the drive is its efficiency. The drives also offer regenerative capability without modification, built-in memory for first-fault indication, and easy troubleshooting with comprehensive self-diagnostics. The drive controls flow in centrifugal applications by adjusting the pumps or fan speed. This provides energy savings over conventional flow control systems. Slip devices, also used to produce variable speed in centrifugal equipment, vary the ''slip'' between the constant-speed motor shaft and the pump or fan shaft. The speed which is not transmitted is dissipated as heat within the slip device itself. The drives are available from stock (100-250 hp) for immediate energy savings on both new and retrofit spplications, with a number of standard features: a remote operator control station provides start-stop and speed selection; acceleration/deceleration are separately adjustable over a range of 2.5 to 35 seconds with 5- to 70-second range available using simple jumper selection; and a coast-to-rest is also available using simple jumper selection. The drive can be operated automatically from an ungrounded 4-20 mA process control signal.

  19. Development of Voltage Sag Compensator and UPS using a Flywheel Induction Motor and an Engine Generator

    NASA Astrophysics Data System (ADS)

    Kato, Shuhei; Takaku, Taku; Sumitani, Hideo; Shimada, Ryuichi

    Flywheel energy storage systems are focused as uninterruptible power supplies (UPS) from the viewpoint of environmental friendliness and high durability performance. Using a low-speed and heavy flywheel, and a low-cost squirrel-cage induction motor/generator, two applications are proposed; 1) 11kW voltage sag compensator using a capacitor self-excited induction generator without semiconductor converters; 2) UPS composed of the flywheel system and an engine generator. From some experimental results, an ideal voltage sag compensator and UPS are realized by the low-technology flywheel system.

  20. Steady-state analysis of a faulted three-phase four-wire system supplying induction motors with neutrals connected and other single-phase line-to-neutral loads

    NASA Technical Reports Server (NTRS)

    Wood, M. E.

    1980-01-01

    Four wire Wye connected ac power systems exhibit peculiar steady state fault characteristics when the fourth wire of three phase induction motors is connected. The loss of one phase of power source due to a series or shunt fault results in currents higher than anticipated on the remaining two phases. A theoretical approach to compute the fault currents and voltages is developed. A FORTRAN program is included in the appendix.

  1. Prediction of induction motor line current spectra from design data

    NASA Astrophysics Data System (ADS)

    Guldemir, Hanifi

    The thesis concentrates on the estimation of the magnitude and frequency of the spectral components of line current that may be used for sensorless speed detection. The prediction method uses a mixture of permeance-mmf, finite element and reluctance mesh techniques to establish the air gap magnetic field. This traditional type of approach is chosen to maintain a visible link between cause and effect so enhancing understanding. The approach is enhanced by the use of slot permanence effects calculated by finite element techniques where saturation due to the current carrying conductors in the slots is incorporated. This is essential for closed slots. Further enhancements include examining slot permeance effects over one or more poles so that the influence of the spatial distribution of slot currents, and slot top saturation can be incorporated. The harmonic chain equivalent circuit is extensively modified to provide a vehicle for predicting the correct saturation conditions in a skewed machine and the correct winding currents for the field solutions. Rotor pole aliasing is introduced to explain the large number of independent speed harmonic terms found experimentally. Special equivalent circuits are introduced to enable these current harmonic to be predicted. A thorough experimental validation is then conducted of the model using a 30 kW experimental machine with adjustable eccentricity with rotors of different slotting form, slot number and skew to determine their effect on the speed dependent harmonic components. Very good agreement is demonstrated. Finally, the improved prediction model is used to provide information on the significance of saturation, skew, slot number and rotor eccentricity on the level of speed dependent harmonic signals. All of this information helps formulate important rules to assist in the choice of motors for satisfactory operation with sensorless speed control of drives using RSH. This in itself is an important extension to the knowledge

  2. A novel sliding-mode control of induction motor using space vector modulation technique.

    PubMed

    Fu, Tian-Jun; Xie, Wen-Fang

    2005-10-01

    This paper presents a novel sliding-mode control method for torque control of induction motors. The control principle is based on sliding-mode control combined with space vector modulation technique. The sliding-mode control contributes to the robustness of induction motor drives, and the space vector modulation improves the torque, flux, and current steady-state performance by reducing the ripple. The Lyapunov direct method is used to ensure the reaching and sustaining of sliding mode and stability of the control system. The performance of the proposed system is compared with those of conventional sliding-mode controller and classical PI controller. Finally, computer simulation results show that the proposed control scheme provides robust dynamic characteristics with low torque ripple. PMID:16294775

  3. Stability synthesis of control system in current fed inverter driven induction motor

    SciTech Connect

    Veda, R.; Irisa, T.; Ito, T.; Mochizuki, T.; Sonoda, T.

    1983-01-01

    This paper presents a new method of synthesizing a stabilizing control system in current fed inverter driven induction motor (CFIDIM). The method is focused on rotor dynamics and a concept of ''damping torque coefficient (DTC)'' is introduced concerning the electrical torque. At first the control system is synthesized on the assumption that an induction motor is driven by an ideally controllable current source. Then perturbed linearized technique indicates that the system can be stabilized if the stator current or frequency is controlled so as to make the DTC positive by feeding back a signal composed of rotor speed. Next, based on this fact, an approach of synthesizing the converter output voltage is presented under a fixed stator frequency. This result clarifies that the stable operation can be achieved by controlling the voltage in proportion to the acceleration of rotor speed or the deviation of electrical torque. These analytical results are verified with laboratory field tests.

  4. Tuning the stator resistance of induction motors using artificial neural network

    SciTech Connect

    Cabrera, L.A.; Elbuluk, M.E.; Husain, I.

    1997-09-01

    Tuning the stator resistance of induction motors is very important, especially when it is used to implement direct torque control (DTC) in which the stator resistance is a main parameter. In this paper, an artificial network (ANN) is used to accomplish tuning of the stator resistance of an induction motor. The parallel recursive prediction error and backpropagation training algorithms were used in training the neural network for the simulation and experimental results, respectively. The neural network used to tune the stator resistance was trained on-line, making the DTC strategy more robust and accurate. Simulation results are presented for three different neural-network configurations showing the efficiency of the tuning process. Experimental results were obtained for the one of the three neural-network configuration. Both simulation and experimental results showed that the ANN have tuned the stator resistance in the controller to track actual resistance of the machine.

  5. Adaptative Variable Structure Control for an Online Tuning Direct Vector Controlled Induction Motor Drives

    NASA Astrophysics Data System (ADS)

    Lasaad, Sbita; Dalila, Zaltni; Naceurq, Abdelkrim Mohamed

    This study demonstrates that high performance speed control can be obtained by using an adaptative sliding mode control method for a direct vector controlled Squirrel Cage Induction Motor (SCIM). In this study a new method of designing a simple and effective adaptative sliding mode rotational speed control law is developed. The design includes an accurate sliding mode flux observation from the measured stator terminals and rotor speed. The performance of the Direct Field-Orientation Control (DFOC) is ensured by online tuning based on a Model Reference Adaptative System (MRAS) rotor time constant estimator. The control strategy is derived in the sense of Lyapunov stability theory so that the stable tracking performance can be guaranteed under the occurrence of system uncertainties and external disturbances. The proposed scheme is a solution for a robust and high performance induction motor servo drives. Simulation results are provided to validate the effectiveness and robustness of the developed methodology.

  6. Induction motor fault diagnosis based on the k-NN and optimal feature selection

    NASA Astrophysics Data System (ADS)

    Nguyen, Ngoc-Tu; Lee, Hong-Hee

    2010-09-01

    The k-nearest neighbour (k-NN) rule is applied to diagnose the conditions of induction motors. The features are extracted from the time vibration signals while the optimal features are selected by a genetic algorithm based on a distance criterion. A weight value is assigned to each feature to help select the best quality features. To improve the classification performance of the k-NN rule, each of the k neighbours are evaluated by a weight factor based on the distance to the test pattern. The proposed k-NN is compared to the conventional k-NN and support vector machine classification to verify the performance of an induction motor fault diagnosis.

  7. Diagnostics of an induction-motor rotor by the spectral analysis of stator currents

    NASA Astrophysics Data System (ADS)

    Weinreb, K.

    2013-12-01

    A method for achieving more efficient revealing and more unambiguous evaluation of various kinds of defects in the induction-motor (IM) rotor, which is based on changes occurring in the characteristic signs of the spectrum of the stator current, is presented. The results and analysis of measurements performed for artificially specified cases of faults in the rotor of a small-capacity IM are presented.

  8. Performance of station service induction motors following full load rejection of a nuclear generating unit

    SciTech Connect

    Rogers, G.J.; Beaulieu, R.E.; Hajagos, L.M.

    1995-08-01

    In this paper the authors describe simulations, using EPRI`s Extended Transient Midterm Stability Program (ETMSP), which were performed to understand the nature of a failed load rejection test on a nuclear unit. The failure was a result of large induction motors stalling, causing protective relays to operate. Potential remedial measures were simulated and a final solution, using a temporary voltage boost on the AVR, adopted and implemented to prevent further failures.

  9. MRAS state estimator for speed sensorless ISFOC induction motor drives with Luenberger load torque estimation.

    PubMed

    Zorgani, Youssef Agrebi; Koubaa, Yassine; Boussak, Mohamed

    2016-03-01

    This paper presents a novel method for estimating the load torque of a sensorless indirect stator flux oriented controlled (ISFOC) induction motor drive based on the model reference adaptive system (MRAS) scheme. As a matter of fact, this method is meant to inter-connect a speed estimator with the load torque observer. For this purpose, a MRAS has been applied to estimate the rotor speed with tuned load torque in order to obtain a high performance ISFOC induction motor drive. The reference and adjustable models, developed in the stationary stator reference frame, are used in the MRAS scheme in an attempt to estimate the speed of the measured terminal voltages and currents. The load torque is estimated by means of a Luenberger observer defined throughout the mechanical equation. Every observer state matrix depends on the mechanical characteristics of the machine taking into account the vicious friction coefficient and inertia moment. Accordingly, some simulation results are presented to validate the proposed method and to highlight the influence of the variation of the inertia moment and the friction coefficient on the speed and the estimated load torque. The experimental results, concerning to the sensorless speed with a load torque estimation, are elaborated in order to validate the effectiveness of the proposed method. The complete sensorless ISFOC with load torque estimation is successfully implemented in real time using a digital signal processor board DSpace DS1104 for a laboratory 3 kW induction motor. PMID:26775088

  10. Magnetic rotor flux observer of induction motors with fast convergence and less transient oscillation

    NASA Astrophysics Data System (ADS)

    Park, Chang-Woo; Hwang, Jung-Hoon

    2013-03-01

    This paper presents an observer design for the estimation of magnetic rotor flux of induction motors. We characterize the class of MIMO induction motor systems that consists of the linear observable and the nonlinear part with a block triangular structure. The similarity transformation that plays an important role in proving the convergence of the proposed observer is generalized to the systems. Since the gain of the proposed observer minimizes a nonlinear part of the system to suppress for the stability of the error dynamics, it improves the transient performance of the high gain observer. Moreover, by using the generalized similarity transformation, it is shown that under some observability and boundedness conditions, the proposed observer guarantees the global exponential convergence to zero of the estimation error. Since the proposed scheme minimizes the nonlinearity of an induction motor system, it improves the transient performance of the observer and guarantees the global exponential convergence to zero of the estimation error. The estimation results of magnetic rotor fluxes through experiments are shown and it is presented that the proposed magnetic flux observer exhibits less transient oscillation and faster convergence time than the general observer.

  11. Sensorless Control of Synchronous Reluctance Motors based on an Extended Electromotive Force Model and Inductance Measurement in the Model

    NASA Astrophysics Data System (ADS)

    Ichikawa, Shinji; Tomita, Mutuwo; Doki, Shinji; Okuma, Shigeru

    In this paper, sensorless control for synchronous reluctance motors (SynRMs) without signal injection and an inductance measurement for position estimation are proposed. In the case of SynRMs, accuracy of inductances is the most important thing to realize precise position estimation because inductances are largely varied by a magnetic saturation phenomenon. Therefore, the inductance measurement method, which can measure appropriate inductances for position estimation, is important as well as a sensorless control method. The inductance measurement based on the observer is discussed, and the measurement method and the parameter adjustment method for improvement in stability of the closed loop are proposed. The proposed method can measure inductances easily and be applied for permanent magnet synchronous motors, too. Finally, the proposed sensorless control method is verified by experiments.

  12. AC electrokinetic drug delivery in dentistry using an interdigitated electrode assembly powered by inductive coupling.

    PubMed

    Ivanoff, Chris S; Wu, Jie Jayne; Mirzajani, Hadi; Cheng, Cheng; Yuan, Quan; Kevorkyan, Stepan; Gaydarova, Radostina; Tomlekova, Desislava

    2016-10-01

    AC electrokinetics (ACEK) has been shown to deliver certain drugs into human teeth more effectively than diffusion. However, using electrical wires to power intraoral ACEK devices poses risks to patients. The study demonstrates a novel interdigitated electrode arrays (IDE) assembly powered by inductive coupling to induce ACEK effects at appropriate frequencies to motivate drugs wirelessly. A signal generator produces the modulating signal, which multiplies with the carrier signal to produce the amplitude modulated (AM) signal. The AM signal goes through the inductive link to appear on the secondary coil, then rectified and filtered to dispose of its carrier signal, and the positive half of the modulating signal appears on the load. After characterizing the device, the device is validated under light microscopy by motivating carboxylate-modified microspheres, tetracycline, acetaminophen, benzocaine, lidocaine and carbamide peroxide particles with induced ACEK effects. The assembly is finally tested in a common dental bleaching application. After applying 35 % carbamide peroxide to human teeth topically or with the IDE at 1200 Hz, 5 Vpp for 20 min, spectrophotometric analysis showed that compared to diffusion, the IDE enhanced whitening in specular optic and specular optic excluded modes by 215 % and 194 % respectively. Carbamide peroxide absorbance by the ACEK group was two times greater than diffusion as measured by colorimetric oxidation-reduction and UV-Vis spectroscopy at 550 nm. The device motivates drugs of variable molecular weight and structure wirelessly. Wireless transport of drugs to intraoral targets under ACEK effects may potentially improve the efficacy and safety of drug delivery in dentistry. PMID:27565821

  13. RBFN Based Efficiency Optimization Method of Induction Motor Utilized in Electrically Driven Marine Propellers

    NASA Astrophysics Data System (ADS)

    Supari; Syafaruddin; Negara, I. Made Yulistya; Ashari, Mochamad; Hiyama, Takashi

    Thruster controllers of electric propulsion system with fixed pitch propellers are conventionally aimed to control only the shaft speed without utilizing the capabilities of the controllers to apply any other control strategies. In fact, the dynamic operating conditions lead to the fluctuation of motor load. For this reason, utilizing conventional controllers is hard enough due to the critical constraints and limitation of the ship power source. The paper presents study and analysis of efficiency optimization strategy in thruster shaft speed controllers driven by induction motor. The control strategy based on intelligent method called radial basis function neural network (RBFN) is implemented. A set of training data derived from a loss model controller of the induction motor working under indirect field-oriented-control (IFOC) drives is used for training process of RBFN. The loss model controller utilizes schematically the flux generating current as controlling variable. Estimation of the flux generating current through the RBFN process shows significant improvement in motor efficiency especially for low speed and ship transit system.

  14. Smart Technique for Induction Motors Diagnosis by Monitoring the Power Factor Using Only the Measured Current

    NASA Astrophysics Data System (ADS)

    Shnibha, R. A.; Albarabar, A. S.

    2012-05-01

    This paper is concerned with accurate, early and reliable induction motor IM fault detection and diagnosis using an enhanced power parameter measurement technique. IM protection devices typically monitor the motor current and/or voltage to provide the motor protection from e.g. current overload, over/under voltage, etc. One of the interesting parameters to monitor is the operating power factor (PF) of the IM which provides better under-load protection compared to the motor current based approaches. The PF of the motor is determined by the level of the current and voltage that are drawn, and offers non-intrusive monitoring. Traditionally, PF estimation would require both voltage and the current measurements to apply the displacement method. This paper will use a method of determining the operating PF of the IM using only the measured current and the manufacturer data that are typically available from the nameplate and/or datasheet for IM monitoring. The novelty of this work lies in detecting very low phase imbalance related faults and misalignment. Much of the previous work has dealt with detecting phase imbalance faults at higher degrees of severity, i.e. voltage drops of 10% or more. The technique was tested by empirical measurements on test rig comprised a 1.1 kW variable speed three phase induction motor with varying output load (No load, 25%, 50%, 75% and 100% load). One common faults was introduced; imbalance in one phase as the electrical fault The experimental results demonstrate that the PF can be successfully applied for IM fault diagnosis and the present study shows that severity fault detection using PF is promising. The proposed method offers a potentially reliable, non-intrusive, and inexpensive CM tool which can be implemented with real-time monitoring systems

  15. Application to induction motor faults diagnosis of the amplitude recovery method combined with FFT

    NASA Astrophysics Data System (ADS)

    Liu, Yukun; Guo, Liwei; Wang, Qixiang; An, Guoqing; Guo, Ming; Lian, Hao

    2010-11-01

    This paper presents a signal processing method - amplitude recovery method (abbreviated to ARM) - that can be used as the signal pre-processing for fast Fourier transform (FFT) in order to analyze the spectrum of the other-order harmonics rather than the fundamental frequency in stator currents and diagnose subtle faults in induction motors. In this situation, the ARM functions as a filter that can filter out the component of the fundamental frequency from three phases of stator currents of the induction motor. The filtering result of the ARM can be provided to FFT to do further spectrum analysis. In this way, the amplitudes of other-order frequencies can be extracted and analyzed independently. If the FFT is used without the ARM pre-processing and the components of other-order frequencies, compared to the fundamental frequency, are fainter, the amplitudes of other-order frequencies are not able easily to extract out from stator currents. The reason is when the FFT is used direct to analyze the original signal, all the frequencies in the spectrum analysis of original stator current signal have the same weight. The ARM is capable of separating the other-order part in stator currents from the fundamental-order part. Compared to the existent digital filters, the ARM has the benefits, including its stop-band narrow enough just to stop the fundamental frequency, its simple operations of algebra and trigonometry without any integration, and its deduction direct from mathematics equations without any artificial adjustment. The ARM can be also used by itself as a coarse-grained diagnosis of faults in induction motors when they are working. These features can be applied to monitor and diagnose the subtle faults in induction motors to guard them from some damages when they are in operation. The diagnosis application of ARM combined with FFT is also displayed in this paper with the experimented induction motor. The test results verify the rationality and feasibility of the

  16. Universal Parameter Measurement and Sensorless Vector Control of Induction and Permanent Magnet Synchronous Motors

    NASA Astrophysics Data System (ADS)

    Yamamoto, Shu; Ara, Takahiro

    Recently, induction motors (IMs) and permanent-magnet synchronous motors (PMSMs) have been used in various industrial drive systems. The features of the hardware device used for controlling the adjustable-speed drive in these motors are almost identical. Despite this, different techniques are generally used for parameter measurement and speed-sensorless control of these motors. If the same technique can be used for parameter measurement and sensorless control, a highly versatile adjustable-speed-drive system can be realized. In this paper, the authors describe a new universal sensorless control technique for both IMs and PMSMs (including salient pole and nonsalient pole machines). A mathematical model applicable for IMs and PMSMs is discussed. Using this model, the authors derive the proposed universal sensorless vector control algorithm on the basis of estimation of the stator flux linkage vector. All the electrical motor parameters are determined by a unified test procedure. The proposed method is implemented on three test machines. The actual driving test results demonstrate the validity of the proposed method.

  17. Sensor-less pseudo-sinusoidal drive for a permanent-magnet brushless ac motor

    NASA Astrophysics Data System (ADS)

    Liu, Li-Hsiang; Chern, Tzuen-Lih; Pan, Ping-Lung; Huang, Tsung-Mou; Tsay, Der-Min; Kuang, Jao-Hwa

    2012-04-01

    The precise rotor-position information is required for a permanent-magnet brushless ac motor (BLACM) drive. In the conventional sinusoidal drive method, either an encoder or a resolver is usually employed. For position sensor-less vector control schemes, the rotor flux estimation and torque components are obtained by complicated coordinate transformations. These computational intensive methods are susceptible to current distortions and parameter variations. To simplify the method complexity, this work presents a sensor-less pseudo-sinusoidal drive scheme with speed control for a three-phase BLACM. Based on the sinusoidal drive scheme, a floating period of each phase current is inserted for back electromotive force detection. The zero-crossing point is determined directly by the proposed scheme, and the rotor magnetic position and rotor speed can be estimated simultaneously. Several experiments for various active angle periods are undertaken. Furthermore, a current feedback control is included to minimize and compensate the torque fluctuation. The experimental results show that the proposed method has a competitive performance compared with the conventional drive manners for BLACM. The proposed scheme is straightforward, bringing the benefits of sensor-less drive and negating the need for coordinate transformations in the operating process.

  18. The pulsed linear induction motor concept for high-speed trains

    SciTech Connect

    Turman, B.N.; Marder, B.M.; Rohwein, G.J.; Aeschliman, D.P.; Kelley, J.B.; Cowan, M.; Zimmerman, R.M.

    1995-06-01

    The SERAPBIM (SEgmented RAil PHased Induction Motor) concept is a linear induction motor concept which uses rapidly-pulsed magnetic fields and a segmented reaction rail, as opposed to low-frequency fields and continuous reaction rails found in conventional linear induction motors. These improvements give a high-traction, compact, and efficient linear motor that has potential for advanced high speed rail propulsion. In the SERAPBIM concept, coils on the vehicle push against a segmented aluminum rail, which is mounted on the road bed. Current is pulsed as the coils cross an edge of the segmented rail, inducing surface currents which repel the coil. The coils must be pulsed in synchronization with the movement by reaction rail segments. This is provided by a sense-and-fire circuit that controls the pulsing of the power modulators. Experiments were conducted to demonstrate the feasibility of the pulsed induction motor and to collect data that could be used for scaling calculations. A 14.4 kg aluminum plate was accelerated down a 4 m track to speeds of over 15 m/sec with peak thrust up to 18 kN per coilset. For a trainset capable of 200 mph speed, the SERAPHIM concept design is based on coils which are each capable of producing up to 3.5 kN thrust, and 30 coil pairs are mounted on each power car. Two power cars, one at each end of the train, provide 6 MW from two gas turbine prime power units. The thrust is about 210.000 N and is essentially constant up to 200 km/hr since wheel slippage does not limit thrust as with conventional wheeled propulsion. A key component of the SERAPHIM concept is the use of passive wheel-on-rah support for the high speed vehicle. Standard steel wheels are capable of handling over 200 mph. The SERAPHIM cost is comparable to that for steel-wheel high-speed rail, and about 10% to 25% of the projected costs for a comparable Maglev system.

  19. High-power CSI-fed induction motor drive with optimal power distribution based control

    NASA Astrophysics Data System (ADS)

    Kwak, S.-S.

    2011-11-01

    In this article, a current source inverter (CSI) fed induction motor drive with an optimal power distribution control is proposed for high-power applications. The CSI-fed drive is configured with a six-step CSI along with a pulsewidth modulated voltage source inverter (PWM-VSI) and capacitors. Due to the PWM-VSI and the capacitor, sinusoidal motor currents and voltages with high quality as well as natural commutation of the six-step CSI can be obtained. Since this CSI-fed drive can deliver required output power through both the six-step CSI and PWM-VSI, this article shows that the kVA ratings of both the inverters can be reduced by proper real power distribution. The optimal power distribution under load requirements, based on power flow modelling of the CSI-fed drive, is proposed to not only minimise the PWM-VSI rating but also reduce the six-step CSI rating. The dc-link current control of the six-step CSI is developed to realise the optimal power distribution. Furthermore, a vector controlled drive for high-power induction motors is proposed based on the optimal power distribution. Experimental results verify the high-power CSI-fed drive with the optimal power distribution control.

  20. A new diagnosis of broken rotor bar fault extent in three phase squirrel cage induction motor

    NASA Astrophysics Data System (ADS)

    Shi, Pu; Chen, Zheng; Vagapov, Yuriy; Zouaoui, Zoubir

    2014-01-01

    This paper proposes a new induction motor broken bar fault extent diagnostic approach under varying load conditions based on wavelet coefficients of stator current in a specific frequency band. In this paper, winding function approach (WFA) is used to develop a mathematical model to provide indication references for parameters under different load levels and different fault cases. It is shown that rise of number of broken bars and load levels increases amplitude of the particular side band components of the stator currents in faulty case. Stator current, rotor speed and torque are used to demonstrate the relationship between these parameters and broken rotor bar severity. An induction motor with 1, 2 and 3 broken bars and the motor with 3 broken bars in experiment at no-load, 50% and 100% load are investigated. A novel criterion is then developed to assess rotor fault severity based on the stator current and the rotor speed. Simulations and experimental results confirm the validity of the proposed approach.

  1. Comparison of Alternative Equivalent Circuits of Induction Motor with Real Machine Data

    NASA Astrophysics Data System (ADS)

    Bradna, J.; Bauer, J.; Fligl, S.; Hlinovsky, V.

    The algorithms based on separated control of the motor flux and torque is used in order to gain the maximum performance from the induction machine. To push the efficiency and dynamics limits of the IM to its limits mostly FOC or DTC control strategies are used. Both are based on the knowledge of the hardly measurable variable-machine flux. To obtain the information about inner machine flux models based on the machine equivalent circuit are mostly used. Therefore the accuracy of the equivalent circuits has direct influence on the accuracy of the machine control. To reduce the complexity of the mathematical model the resistances and inductances are concentrated to one component and three phase winding is assumed to be symmetrical. In order to design control strategy for the induction motor, system equations and equivalent circuit must be established at first. This paper examines and compares some of the issues of adequate machine modeling and attempts to provide a firmer basis for selection of an appropriate model and to confirm or disprove the equivalence of different approaches. The results of the IM model run up are then compared to the results obtained from the measurements on the real machine and the equivalency is discussed.

  2. A new direct torque control scheme for induction motors using linear state feedback

    SciTech Connect

    Kandianis, A.; Manias, S.N.; Griva, G.; Profumo, F.

    1995-12-31

    In this paper a new Direct Torque Control (DTC) scheme for induction motor drives is described, based on the linear state feedback method with dynamic output feedback. The DTC has been shown to be a good solution in torque controlled drives applications when the speed control is not required (e.g. traction drives for electric vehicles). In such cases, the torque command comes directly from the user input. By considering the torque and flux as the outputs of the linearized motor model, it is possible to design an optimum controller with constant gain state feedback and dynamic output feedback through an integral term. The design procedure of the proposed control scheme is described and the simulation results are presented to show the overall performance of the system.

  3. Two simple and novel SISO controllers for induction motors based on adaptive passivity.

    PubMed

    Travieso-Torres, Juan C; Duarte-Mermoud, Manuel A

    2008-01-01

    The design of two single-input single-output (SISO) controllers for induction motors based on adaptive passivity is presented in this paper. The two controllers work together with a field orientation block. Because of the adaptive nature of the proposed controllers, the knowledge of the set motor-load parameters is not needed and robustness under variations of such parameters is guaranteed. Simple proportional controllers for the torque, rotor flux and stator current control loops are used, due to the control simplification given by the use of feedback passive equivalence. A new principle called the "Torque-Flux Control Principle" is also stated in this article, which considerably simplifies the controller design, diminishing the control efforts and avoiding also rotor flux estimation. PMID:17714715

  4. High Ripples Reduction in DTC of Induction Motor by Using a New Reduced Switching Table

    NASA Astrophysics Data System (ADS)

    Mokhtari, Bachir; Benkhoris, Mohamed F.

    2016-05-01

    The direct torque and flux control (DTC) of electrical motors is characterized by ripples of torque and flux. Among the many solutions proposed to reduce them is to use modified switching tables which is very advantageous; because its implementation is easy and requires no additional cost compared to other solutions. This paper proposes a new reduced switching table (RST) to improve the DTC by reducing harmful ripples of torque and flux. This new switching table is smaller than the conventional one (CST) and depends principally at the flux error. This solution is studied by simulation under Matlab/Simulink and experimentally validated on a testbed with DSPACE1103. The results obtained of a DTC with RST applied to a three-phase induction motor (IM) show a good improvement and an effectiveness of proposed solution, the torque ripple decreases about 47% and 3% for the stator flux compared with a basic DTC.

  5. An analysis and an operating method of switched reluctance motors based on a simple inductance representation

    SciTech Connect

    Chiba, Akira; Fukao, Tadashi

    1995-12-31

    In this paper, a mathematical analysis based on a simple model is carried out. The operating characteristics of switched reluctance motors fed by square waveform voltage are analyzed. Inductance variations with respect to the rotor rotational position is approximated with only a sinusoidal function and a constant. Square waveform voltage is approximated by a fundamental component only. Based on this simple representation, it is possible to analyze operating characteristics mathematically in normalized planes and to derive a general control method. It is found that there exists a particular voltage phase angle which realizes the maximum output per current. It was also found that the maximum output per voltage can be achieved at the another particular voltage phase angle. These characteristics are found to be very similar to those of synchronous reluctance motors. As a result of the analysis, an efficient operating method is proposed. These results are confirmed by a 6,000 r/min., 2kW prototype machine.

  6. Analysis of induction motors based on the numerical solution of the magnetic field and circuit equations

    NASA Astrophysics Data System (ADS)

    Arkkio, Antero

    1987-12-01

    A method for the analysis of induction motors based on the combined solution of the magnetic field equations and the circuit equations of the windings is presented. The equations are discretized by the finite element method. The magnetic field is assumed to be two-dimensional. The three-dimensional features, i.e., the skew of the rotor slots and the end-region fields, are taken into account within the two-dimensional formulation. The general time-dependence of the field and the motion of the rotor are modelled correctly in a step-by-step solution. The amount of computation is reduced significantly if the time-dependence is assumed to be sinusoidal and phasor quantities are used in the solution. The method is applied to the calculation of a cage rotor motor and of a solid rotor motor. The sinusoidal approximation gives good results in the computation of steady-state locked-rotor quantities, but it does not model the motion of the rotor properly. The step-by-step method is used for computing machine quantities in steady and transient states. The operation of the solid rotor motor supplied by a static frequency converter is simulated. The results obtained by the method agree well with the measured ones.

  7. Torque Ripple Reduction in Direct Torque Control Based Induction Motor using Intelligent Controllers

    NASA Astrophysics Data System (ADS)

    Sudhakar, Ambarapu; Vijaya Kumar, M.

    2015-09-01

    This paper presents intelligent control scheme together with conventional control scheme to overcome the problems with uncertainties in the structure encountered with classical model based design of induction motor drive based on direct torque control (DTC). It allows high dynamic performance to be obtained with very simple hysteresis control scheme. Direct control of the torque and flux is achieved by proper selection of inverter voltage space vector through a lookup table. This paper also presents the application of intelligent controllers like neural network and fuzzy logic controllers to control induction machines with DTC. Intelligent controllers are used to emulate the state selector of the DTC. With implementation of intelligent controllers the system is also verified and proved to be operated stably with reduced torque ripple. The proposed method validity and effectiveness has been verified by computer simulations using Matlab/Simulink®. These results are compared with the ones obtained with a classical DTC using proportional integral speed controller.

  8. Internal Model Controller of an ANN Speed Sensorless Controlled Induction Motor Drives

    NASA Astrophysics Data System (ADS)

    Hamed Mouna, Ben; Lassaad, Sbita

    This study deals with the performance analysis and implementation of a robust sensorless speed controller. The robustness is guaranteed by the use of the Internal Model Controller (IMC). An intelligent algorithm is evolved to eliminate the mechanical speed. It is based on the Artificial Neural Network (ANN) principle. Verification of the proposed robust sensorless controller is provided by experimental realistic tests on a scalar controlled induction motor drive. Sensorless robust speed control at low speeds and in field weakening region (high speeds) is studied in order to show the robustness of the speed controller under a wide range of load.

  9. Influence of the inverter characteristics on the iron losses in PWM inverter fed induction motors

    SciTech Connect

    Boglietti, A.; Ferraris, P.; Lazzari, M.; Pastorelli, M.

    1995-12-31

    In this paper the authors deal with the effects of the inverter characteristics on the iron losses increment in induction motors fed by PWM controlled converters. Laboratory tests based on no-load input power measurement were carried out and in order to avoid the influence of mechanical losses and rotor copper losses, difficult to be measured or computed, a special test bench with an unconventional test device was employed. In particular the influence of the following inverter parameters are considered: modulation index; modulation waveform; switching frequency. Complete experimental results are presented and discussed.

  10. Identification of significant intrinsic mode functions for the diagnosis of induction motor fault.

    PubMed

    Cho, Sangjin; Shahriar, Md Rifat; Chong, Uipil

    2014-08-01

    For the analysis of non-stationary signals generated by a non-linear process like fault of an induction motor, empirical mode decomposition (EMD) is the best choice as it decomposes the signal into its natural oscillatory modes known as intrinsic mode functions (IMFs). However, some of these oscillatory modes obtained from a fault signal are not significant as they do not bear any fault signature and can cause misclassification of the fault instance. To solve this issue, a novel IMF selection algorithm is proposed in this work. PMID:25096149

  11. Emotional Learning Based Intelligent Controllers for Rotor Flux Oriented Control of Induction Motor

    NASA Astrophysics Data System (ADS)

    Abdollahi, Rohollah; Farhangi, Reza; Yarahmadi, Ali

    2014-08-01

    This paper presents design and evaluation of a novel approach based on emotional learning to improve the speed control system of rotor flux oriented control of induction motor. The controller includes a neuro-fuzzy system with speed error and its derivative as inputs. A fuzzy critic evaluates the present situation, and provides the emotional signal (stress). The controller modifies its characteristics so that the critics stress is reduced. The comparative simulation results show that the proposed controller is more robust and hence found to be a suitable replacement of the conventional PI controller for the high performance industrial drive applications.

  12. Rotor Speed Detection Method for Vector Control of Induction Motor without Speed Sensor Utilizing Slot Harmonics

    NASA Astrophysics Data System (ADS)

    Kiyotake, Hirofumi; Shinohara, Katsuji; Yamamoto, Kichiro

    Speed sensorless vector controlled induction motor drives are the standard choice in many industrial applications, but this can hardly control torque and rotor speed at low speed. Recently, a method based on the high-frequency signal injection has been studied. This paper presents a method for suppressing the effects of the saturation saliency by using high pass filter, and a new approach to estimate the rotor speed. The effectiveness of these methods are demonstrated through experimental results showing both good suppression of saturation harmonics and good sensorless speed control at low speed.

  13. Analysis of axially non-uniform loss distribution in 3-phase induction motor considering skew effect

    SciTech Connect

    Kown, B.I.; Kim, B.T.; Jun, C.S.; Park, S.C. )

    1999-05-01

    This paper discusses the phenomena of the axially non-uniform distribution of magnetic flux densities and losses in a 3-phase squirrel cage induction motor of which the rotor bars are skewed. A 2-dimensional complex finite element method taking account of the effects of the skewed rotor bars is utilized for the analysis of characteristics such as copper and iron losses and the loss distributions are examined. The summing up values of non-uniform losses resulted from the finite element analysis are compared with measurement values.

  14. Finite element analysis of direct thrust-controlled linear induction motor

    SciTech Connect

    Kwon, B.I.; Woo, K.I.; Kim, S. . Dept. of Electrical Engineering)

    1999-05-01

    This paper describes the finite element analysis of a direct thrust-controlled linear induction motor (LIM). The time-stepping finite element method and the moving mesh technique are used to calculate the dynamic characteristics of LIM during the direct thrust control. Because LIM has the end effect, thrust correction coefficient is introduced to predict an actual thrust in control. The simulation results, the thrust and the stator flux linkage are shown below and the stator current is compared with an experimental one.

  15. Distribution of local magnetic properties in three-phase induction motor model core

    SciTech Connect

    Enokizono, M.; Morikawa, M.; Fujiyama, S.; Sievert, J.; Serikawa, I.

    1999-09-01

    Efficiency improvement of electrical machines, is a very important problem. However the local magnetic properties in core materials have not yet understood fully. On the other hand, the concept of the two-dimensional magnetic property has been reported. It means the relationship between the magnetic field strength vector H and the flux density vector B. They are not usually parallel but have a phase angle in space. This paper presents the measured local vector-magnetic properties in a three-phase induction motor model core.

  16. Finite element analysis of induction motors based on computing detailed equivalent circuit parameters

    SciTech Connect

    Zhou, P.; Gilmore, J.; Badics, Z.; Cendes, Z.J.

    1998-09-01

    A method for accurately predicting the steady-state performance of squirrel cage induction motors is presented. The approach is based on the use of complex two-dimensional finite element solutions to deduce per-phase equivalent circuit parameters for any operating condition. Core saturation and skin effect are directly considered in the field calculation. Corrections can be introduced to include three-dimensional effects such as end-winding and rotor skew. An application example is provided to demonstrate the effectiveness of the proposed approach.

  17. DWT analysis of numerical and experimental data for the diagnosis of dynamic eccentricities in induction motors

    NASA Astrophysics Data System (ADS)

    Antonino-Daviu, J.; Jover, P.; Riera, M.; Arkkio, A.; Roger-Folch, J.

    2007-08-01

    The behaviour of an induction machine during a startup transient can provide useful information for the diagnosis of electromechanical faults. During this process, the machine works under high stresses and the effects of the faults may also be larger than those in steady-state. These facts may help to amplify the magnitude of the indicators of some incipient faults. In addition, fault components with frequencies dependant on the slip evolve in a particular way during that transient, a fact that allows the diagnosis of the corresponding fault and the discrimination between different faults. The discrete wavelet transform (DWT) is an ideal tool for analysing signals with frequency spectrum variable in time. Some research works have applied with success the DWT to the stator startup current in order to diagnose the presence of broken rotor bars in induction machines. However, few works have used this technique for the study of other common faults, such as eccentricities. In this work, time-frequency analysis of the stator startup current is carried out in order to detect the presence of dynamic eccentricities in an induction motor. For this purpose, the DWT is applied and wavelet signals at different levels are studied. Data are obtained from simulations, using a finite element (FE) model of an induction motor, which allows forcing several kinds of faults in the machine, and also from experimental tests. The results show the validity of the approach for detecting the fault and discriminating with respect to other failures, presenting for certain applications (or working conditions) some advantages over the traditional stationary analysis.

  18. Reduction of Common-Mode Conducted Noise Emissions in PWM Inverter-fed AC Motor Drive Systems using Optimized Passive EMI Filter

    NASA Astrophysics Data System (ADS)

    Jettanasen, C.; Ngaopitakkul, A.

    2010-10-01

    Conducted electromagnetic interference (EMI) generated by PWM inverter-fed induction motor drive systems, which are currently widely used in many industrial and/or avionic applications, causes severe parasitic current problems, especially at high frequencies (HF). These restrict power electronic drive's evolution. In order to reduce or minimize these EMI problems, several techniques can be applied. In this paper, insertion of an optimized passive EMI filter is proposed. This filter is optimized by taking into account real impedances of each part of a considered AC motor drive system contrarily to commercial EMI filters designed by considering internal impedance of disturbance source and load, equal to 50Ω. Employing the latter EMI filter would make EMI minimization less effective. The proposed EMI filter optimization is mainly dedicated to minimize common mode (CM) currents due to its most dominant effects in this kind of system. The efficiency of the proposed optimization method using two-port network approach is deduced by comparing the minimized CM current spectra to an applied normative level (ex. DO-160D in aeronautics).

  19. Estimation of the running speed and bearing defect frequencies of an induction motor from vibration data

    NASA Astrophysics Data System (ADS)

    Ocak, Hasan; Loparo, Kenneth A.

    2004-05-01

    This paper presents two separate algorithms for estimating the running speed and the bearing key frequencies of an induction motor using vibration data. Bearing key frequencies are frequencies at which roller elements pass over a defect point. Most frequency domain-based bearing fault detection and diagnosis techniques (e.g. envelope analysis) rely on vibration measurements and the bearing key frequencies. Thus, estimation of the running speed and the bearing key frequencies are required for failure detection and diagnosis. The paper also incorporates the estimation algorithms with the most commonly used bearing fault detection technique, high-frequency demodulation, to detect bearing faults. Experimental data were used to verify the validity of the algorithms. Data were collected through an accelerometer measuring the vibration from the drive-end ball bearing of an induction motor (Reliance Electric 2HP IQPreAlert)-driven mechanical system. Both inner and outer race defects were artificially introduced to the bearing using electrical discharge machining. A linear vibration model was also developed for generating simulated vibration data. The simulated data were also used to validate the performance of the algorithms. The test results proved the algorithms to be very reliable.

  20. Powerline Coupler for Windmill Motor/Generators

    NASA Technical Reports Server (NTRS)

    Nola, F.

    1985-01-01

    Efficiency at low windspeed increased by firing-angle control. Power coupled from wind-driven induction motor/generator to ac powerline with help from circuit. Circuit reduces power consumed by field windings thereby improving efficiency at low windspeeds. Circuit includes zerocrossing detector, ramp generator and comparator similar to those used to set firing angles for thyristors in power factor motor controllers.

  1. The Experimental Study of Rayleigh-Taylor Instability using a Linear Induction Motor Accelerator

    NASA Astrophysics Data System (ADS)

    Yamashita, Nicholas; Jacobs, Jeffrey

    2009-11-01

    The experiments to be presented utilize an incompressible system of two stratified miscible liquids of different densities that are accelerated in order to produce the Rayleigh-Taylor instability. Three liquid combinations are used: isopropyl alcohol with water, a calcium nitrate solution or a lithium polytungstate solution, giving Atwood numbers of 0.11, 0.22 and 0.57, respectively. The acceleration required to drive the instability is produced by two high-speed linear induction motors mounted to an 8 m tall drop tower. The motors are mounted in parallel and have an effective acceleration length of 1.7 m and are each capable of producing 15 kN of thrust. The liquid system is contained within a square acrylic tank with inside dimensions 76 x76x184 mm. The tank is mounted to an aluminum plate, which is driven by the motors to create constant accelerations in the range of 1-20 g's, though the potential exists for higher accelerations. Also attached to the plate are a high-speed camera and an LED backlight to provide continuous video of the instability. In addition, an accelerometer is used to provide acceleration measurements during each experiment. Experimental image sequences will be presented which show the development of a random three-dimensional instability from an unforced initial perturbation. Measurements of the mixing zone width will be compared with traditional growth models.

  2. Adaptive control schemes for improving dynamic performance of efficiency-optimized induction motor drives.

    PubMed

    Kumar, Navneet; Raj Chelliah, Thanga; Srivastava, S P

    2015-07-01

    Model Based Control (MBC) is one of the energy optimal controllers used in vector-controlled Induction Motor (IM) for controlling the excitation of motor in accordance with torque and speed. MBC offers energy conservation especially at part-load operation, but it creates ripples in torque and speed during load transition, leading to poor dynamic performance of the drive. This study investigates the opportunity for improving dynamic performance of a three-phase IM operating with MBC and proposes three control schemes: (i) MBC with a low pass filter (ii) torque producing current (iqs) injection in the output of speed controller (iii) Variable Structure Speed Controller (VSSC). The pre and post operation of MBC during load transition is also analyzed. The dynamic performance of a 1-hp, three-phase squirrel-cage IM with mine-hoist load diagram is tested. Test results are provided for the conventional field-oriented (constant flux) control and MBC (adjustable excitation) with proposed schemes. The effectiveness of proposed schemes is also illustrated for parametric variations. The test results and subsequent analysis confer that the motor dynamics improves significantly with all three proposed schemes in terms of overshoot/undershoot peak amplitude of torque and DC link power in addition to energy saving during load transitions. PMID:25820090

  3. Immediate Effects of Kinesiology Taping of Quadriceps on Motor Performance after Muscle Fatigued Induction

    PubMed Central

    Ahn, Ick Keun; Kim, You Lim; Bae, Young-Hyeon; Lee, Suk Min

    2015-01-01

    Objectives. The purpose of this cross-sectional single-blind study was to investigate the immediate effects of Kinesiology taping of quadriceps on motor performance after muscle fatigued induction. Design. Randomized controlled cross-sectional design. Subjects. Forty-five subjects participated in this study. Participants were divided into three groups: Kinesiology taping group, placebo taping group, and nontaping group. Methods. Subjects performed short-term exercise for muscle fatigued induction, followed by the application of each intervention. Peak torque test, one-leg single hop test, active joint position sense test, and one-leg static balance test were carried out before and after the intervention. Results. Peak torque and single-leg hopping distance were significantly increased when Kinesiology taping was applied (p < 0.05). But there were no significant effects on active joint position sense and single-leg static balance. Conclusions. We proved that Kinesiology taping is effective in restoring muscle power reduced after muscle fatigued induction. Therefore, we suggest that Kinesiology taping is beneficial for fatigued muscles. PMID:26246835

  4. High-response flux control of direct-field-oriented induction motor with high efficiency taking core loss into account

    SciTech Connect

    Matsuse, Kouki; Yoshizumi, Tatsuya; Katsuta, Seiji; Taniguchi, Shotaro

    1999-01-01

    Stator core loss has significant adverse effects when an induction motor is controlled by the conventional field-oriented method. Therefore, taking core loss into account should make it possible to control the torque very precisely. In this paper, a direct-field-oriented induction motor with a deadbeat rotor flux controller was developed. The method ensures maximum efficiency in the steady state without degradation of the dynamic response. Simulation and experimental results have demonstrated that this method has higher efficiency and good speed response without any degradation in the transient characteristics.

  5. Beta Band Transcranial Alternating (tACS) and Direct Current Stimulation (tDCS) Applied After Initial Learning Facilitate Retrieval of a Motor Sequence

    PubMed Central

    Krause, Vanessa; Meier, Anna; Dinkelbach, Lars; Pollok, Bettina

    2016-01-01

    The primary motor cortex (M1) contributes to the acquisition and early consolidation of a motor sequence. Although the relevance of M1 excitability for motor learning has been supported, the significance of M1 oscillations remains an open issue. This study aims at investigating to what extent retrieval of a newly learned motor sequence can be differentially affected by motor-cortical transcranial alternating (tACS) and direct current stimulation (tDCS). Alpha (10 Hz), beta (20 Hz) or sham tACS was applied in 36 right-handers. Anodal or cathodal tDCS was applied in 30 right-handers. Participants learned an eight-digit serial reaction time task (SRTT; sequential vs. random) with the right hand. Stimulation was applied to the left M1 after SRTT acquisition at rest for 10 min. Reaction times were analyzed at baseline, end of acquisition, retrieval immediately after stimulation and reacquisition after eight further sequence repetitions. Reaction times during retrieval were significantly faster following 20 Hz tACS as compared to 10 Hz and sham tACS indicating a facilitation of early consolidation. tDCS yielded faster reaction times, too, independent of polarity. No significant differences between 20 Hz tACS and tDCS effects on retrieval were found suggesting that 20 Hz effects might be associated with altered motor-cortical excitability. Based on the behavioral modulation yielded by tACS and tDCS one might speculate that altered motor-cortical beta oscillations support early motor consolidation possibly associated with neuroplastic reorganization. PMID:26834593

  6. An Approach to Suppressing Both Shaft Voltage and Leakage Current in an AC Motor Driven by a Voltage-Source PWM Inverter

    NASA Astrophysics Data System (ADS)

    Doumoto, Takafumi; Akagi, Hirofumi

    This paper proposes a practical approach to suppressing both shaft voltage and leakage current in an ac motor driven by a voltage-source PWM inverter. This approach is characterized by using a neutral line of the ac motor. A common-mode inductor is connected between the inverter and the motor. Moreover, a resistor and a capacitor are connected in series between the motor neutral point and the inverter negative dc bus. This unique circuit configuration makes the common-mode inductor effective in reducing the common-mode voltage appearing at the motor terminals. As a result, both shaft voltage and ground current are significantly suppressed with low cost. Over-voltages at the end of a cable can be suppressed by a normal-mode inductor and a resistor which are connected in parallel. The validity and effectiveness of the new approach are verified by experimental results from a 5-kVA laboratory system.

  7. Analytical investigation of torque and flux ripple in induction motor control scheme using wavelet network

    NASA Astrophysics Data System (ADS)

    Liu, Hua; Zhang, Hong; Qin, Aili

    2008-10-01

    An effective scheme of parameter identification based on wavelet neural network is presented for improving dynamic performance of direct torque control system. The wavelet transform is localized in time-frequency domains, yielding wavelet coefficients at different scales. This gives the wavelet transform much greater compact support for analysis of signals with localized transient components. The input nodes of wavelet neural network are current error and change in the current error and the output node is the stator resistance error. To fulfill the network structure parameter, the improved least squares algorithm is used for initialization. The stator flux vector and electromagnetic torque are acquired accurately by the parameter estimator once the instants are detected. This function can make induction motor operate well in low region and can optimize the inverter control strategy. The simulation results show that the proposed method can efficiently reduce the torque ripple and current ripple.

  8. The effects of various magnetic materials on lamination design for stator-rotor diecasting of induction motors for electric vehicle applications

    SciTech Connect

    Elkasabgy, N.M.; Di Pietro, C.

    1994-05-15

    In this paper the authors describe a novel technique to model induction motors with a diecast stator and rotor and to examine the effects of various magnetic materials on the electrical performance of the motor. For electric vehicle applications, a high volume production operation of the electric motor requires the motor to be small and inexpensive. The expensive labor and material used to manufacture the motor encouraged the researchers to find new methods and techniques to reduce the cost and improve the performance. Diecast rotor and stator windings reduce motor cost and size. For diecasting induction motors, the motor laminations should be designed to optimize the electromagnetic field distribution over the cross section and along the axial direction. The magnetic material used for the laminations should also reduce losses and improve the overall efficiency. A 100 hp four-pole induction motor was modeled with finite elements, and the field distribution, the magnetic flux density, and the mechanical performance of the motor were computed using nonlinear magnetostatic and complex steady-state eddy current techniques. The difference in the electrical and mechanical performance of the motor were evaluated for copper and aluminum diecasting. The results show that copper diecasting of the rotor and the stator of the induction motor with magnetic material properties and identified slotting shape is the way to achieve better motor performance and low cost operation. 5 refs.

  9. Empirical mode decomposition and neural networks on FPGA for fault diagnosis in induction motors.

    PubMed

    Camarena-Martinez, David; Valtierra-Rodriguez, Martin; Garcia-Perez, Arturo; Osornio-Rios, Roque Alfredo; Romero-Troncoso, Rene de Jesus

    2014-01-01

    Nowadays, many industrial applications require online systems that combine several processing techniques in order to offer solutions to complex problems as the case of detection and classification of multiple faults in induction motors. In this work, a novel digital structure to implement the empirical mode decomposition (EMD) for processing nonstationary and nonlinear signals using the full spline-cubic function is presented; besides, it is combined with an adaptive linear network (ADALINE)-based frequency estimator and a feed forward neural network (FFNN)-based classifier to provide an intelligent methodology for the automatic diagnosis during the startup transient of motor faults such as: one and two broken rotor bars, bearing defects, and unbalance. Moreover, the overall methodology implementation into a field-programmable gate array (FPGA) allows an online and real-time operation, thanks to its parallelism and high-performance capabilities as a system-on-a-chip (SoC) solution. The detection and classification results show the effectiveness of the proposed fused techniques; besides, the high precision and minimum resource usage of the developed digital structures make them a suitable and low-cost solution for this and many other industrial applications. PMID:24678281

  10. Empirical Mode Decomposition and Neural Networks on FPGA for Fault Diagnosis in Induction Motors

    PubMed Central

    Garcia-Perez, Arturo; Osornio-Rios, Roque Alfredo; Romero-Troncoso, Rene de Jesus

    2014-01-01

    Nowadays, many industrial applications require online systems that combine several processing techniques in order to offer solutions to complex problems as the case of detection and classification of multiple faults in induction motors. In this work, a novel digital structure to implement the empirical mode decomposition (EMD) for processing nonstationary and nonlinear signals using the full spline-cubic function is presented; besides, it is combined with an adaptive linear network (ADALINE)-based frequency estimator and a feed forward neural network (FFNN)-based classifier to provide an intelligent methodology for the automatic diagnosis during the startup transient of motor faults such as: one and two broken rotor bars, bearing defects, and unbalance. Moreover, the overall methodology implementation into a field-programmable gate array (FPGA) allows an online and real-time operation, thanks to its parallelism and high-performance capabilities as a system-on-a-chip (SoC) solution. The detection and classification results show the effectiveness of the proposed fused techniques; besides, the high precision and minimum resource usage of the developed digital structures make them a suitable and low-cost solution for this and many other industrial applications. PMID:24678281

  11. Temperature and Light Control of Three phase Induction Motor Speed Drive by PIC

    NASA Astrophysics Data System (ADS)

    Barsoum, Nader

    2010-06-01

    PIC is a family of Harvard architecture microcontrollers made by Microchip Technology, derived from the PIC1640 originally developed by General Instrument's Microelectronics Division. The name PIC initially referred to "Peripheral Interface Controller". PICs are popular with the developers and the hobbyists due to their low cost, wide availability, large user base, extensive collection of application notes, free development tools, and serial programming (and re-programming with flash memory) capability. In modern days, PIC microcontrollers are used in the industrial world to control many types of equipment, ranging from consumer to specialized devices. They have replaced older types of controllers, including microprocessors. Also, there is a growing need for off-line support of a computer's main processor. The demand is going to grow with more equipment uses more intelligence. In the engineering field for instance, PIC has brought a very positive impact in designing an automation control system and controlling industrial machineries. Accordingly, this paper shows the change in the motor speed by the use of PIC in accordance to the light and level of temperature. The project focuses on programming the PIC by embedded software that detects the temperature and light signals and send it to 3 phase induction motor of 240 volt. A theoretical analysis and the practical approach in achieving this work goal have proved that PIC plays an important role in the field of electronics control.

  12. Feature Extraction using Wavelet Transform for Multi-class Fault Detection of Induction Motor

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, P.; Konar, P.

    2014-01-01

    In this paper the theoretical aspects and feature extraction capabilities of continuous wavelet transform (CWT) and discrete wavelet transform (DWT) are experimentally verified from the point of view of fault diagnosis of induction motors. Vertical frame vibration signal is analyzed to develop a wavelet based multi-class fault detection scheme. The redundant and high dimensionality information of CWT makes it computationally in-efficient. Using greedy-search feature selection technique (Greedy-CWT) the redundancy is eliminated to a great extent and found much superior to the widely used DWT technique, even in presence of high level of noise. The results are verified using MLP, SVM, RBF classifiers. The feature selection technique has enabled determination of the most relevant CWT scales and corresponding coefficients. Thus, the inherent limitations of CWT like proper selection of scales and redundant information are eliminated. In the present investigation `db8' is found as the best mother wavelet, due to its long period and higher number of vanishing moments, for detection of motor faults.

  13. An improved fault-tolerant control scheme for PWM inverter-fed induction motor-based EVs.

    PubMed

    Tabbache, Bekheïra; Benbouzid, Mohamed; Kheloui, Abdelaziz; Bourgeot, Jean-Matthieu; Mamoune, Abdeslam

    2013-11-01

    This paper proposes an improved fault-tolerant control scheme for PWM inverter-fed induction motor-based electric vehicles. The proposed strategy deals with power switch (IGBTs) failures mitigation within a reconfigurable induction motor control. To increase the vehicle powertrain reliability regarding IGBT open-circuit failures, 4-wire and 4-leg PWM inverter topologies are investigated and their performances discussed in a vehicle context. The proposed fault-tolerant topologies require only minimum hardware modifications to the conventional off-the-shelf six-switch three-phase drive, mitigating the IGBTs failures by specific inverter control. Indeed, the two topologies exploit the induction motor neutral accessibility for fault-tolerant purposes. The 4-wire topology uses then classical hysteresis controllers to account for the IGBT failures. The 4-leg topology, meanwhile, uses a specific 3D space vector PWM to handle vehicle requirements in terms of size (DC bus capacitors) and cost (IGBTs number). Experiments on an induction motor drive and simulations on an electric vehicle are carried-out using a European urban driving cycle to show that the proposed fault-tolerant control approach is effective and provides a simple configuration with high performance in terms of speed and torque responses. PMID:23916869

  14. Fast rotor flux control of direct-field-oriented induction motor operating at maximum efficiency using adaptive rotor flux observer

    SciTech Connect

    Matsuse, Kouki; Katsuta, Seiji; Tsukakoshi, Masahiko; Ohta, Masaru; Huang, L.

    1995-12-31

    A method of using an adaptive rotor flux observer to rapidly control the rotor flux of direct-field-oriented induction motors driven by a deadbeat rotor flux controller has been developed. The method ensures maximum efficiency in the steady state without degradation of the dynamic response. Furthermore, to solve the problem of flux current variations that arise from small errors in the measurement of the stator voltage and current, a flux current reference is calculated from the appropriate rotor flux in the steady state. Simulation and experimental results for an induction motor have demonstrated that this method yields the maximum efficiency and good speed response to changes in both torque and motor speed without any degradation in the transient characteristics.

  15. Cortico-muscular coupling and motor performance are modulated by 20 Hz transcranial alternating current stimulation (tACS) in Parkinson’s disease

    PubMed Central

    Krause, Vanessa; Wach, Claudia; Südmeyer, Martin; Ferrea, Stefano; Schnitzler, Alfons; Pollok, Bettina

    2014-01-01

    Parkinson’s disease (PD) is associated with pathologically altered oscillatory activity. While synchronized oscillations between 13 and 30 Hz are increased within a cortico-subcortical network, cortico-muscular coupling (CMC) is decreased. The present study aims at investigating the effect of non-invasive transcranial alternating current stimulation (tACS) of the primary motor cortex (M1) on motor symptoms and motor-cortical oscillations in PD. In 10 PD patients and 10 healthy control subjects, static isometric contraction, dynamic fast finger tapping, and diadochokinesia of the more severely affected hand were investigated prior to and shortly after tACS of the contralateral M1 at 10 Hz vs. 20 Hz vs. sham. During isometric contraction, neuromagnetic activity was recorded using magnetoencephalography. 20 Hz tACS attenuated beta band CMC during isometric contraction and amplitude variability during finger tapping in PD patients but not in healthy control subjects. 10 Hz tACS yielded no significant after-effects. The present data suggest that PD is associated with pathophysiological alterations which abet a higher responsiveness toward frequency-specific tACS – possibly due to pathologically altered motor-cortical oscillatory synchronization at frequencies between 13 and 30 Hz. PMID:24474912

  16. Sensorless FOC Performance Improved with On-Line Speed and Rotor Resistance Estimator Based on an Artificial Neural Network for an Induction Motor Drive.

    PubMed

    Gutierrez-Villalobos, Jose M; Rodriguez-Resendiz, Juvenal; Rivas-Araiza, Edgar A; Martínez-Hernández, Moisés A

    2015-01-01

    Three-phase induction motor drive requires high accuracy in high performance processes in industrial applications. Field oriented control, which is one of the most employed control schemes for induction motors, bases its function on the electrical parameter estimation coming from the motor. These parameters make an electrical machine driver work improperly, since these electrical parameter values change at low speeds, temperature changes, and especially with load and duty changes. The focus of this paper is the real-time and on-line electrical parameters with a CMAC-ADALINE block added in the standard FOC scheme to improve the IM driver performance and endure the driver and the induction motor lifetime. Two kinds of neural network structures are used; one to estimate rotor speed and the other one to estimate rotor resistance of an induction motor. PMID:26131677

  17. Sensorless FOC Performance Improved with On-Line Speed and Rotor Resistance Estimator Based on an Artificial Neural Network for an Induction Motor Drive

    PubMed Central

    Gutierrez-Villalobos, Jose M.; Rodriguez-Resendiz, Juvenal; Rivas-Araiza, Edgar A.; Martínez-Hernández, Moisés A.

    2015-01-01

    Three-phase induction motor drive requires high accuracy in high performance processes in industrial applications. Field oriented control, which is one of the most employed control schemes for induction motors, bases its function on the electrical parameter estimation coming from the motor. These parameters make an electrical machine driver work improperly, since these electrical parameter values change at low speeds, temperature changes, and especially with load and duty changes. The focus of this paper is the real-time and on-line electrical parameters with a CMAC-ADALINE block added in the standard FOC scheme to improve the IM driver performance and endure the driver and the induction motor lifetime. Two kinds of neural network structures are used; one to estimate rotor speed and the other one to estimate rotor resistance of an induction motor. PMID:26131677

  18. Inductive heat property of Fe3O4/polymer composite nanoparticles in an ac magnetic field for localized hyperthermia.

    PubMed

    Zhao, Dong-Lin; Zhang, Hai-Long; Zeng, Xian-Wei; Xia, Qi-Sheng; Tang, Jin-Tian

    2006-12-01

    The magnetite (Fe(3)O(4)) nanoparticles were prepared by coprecipitation of Fe(3+) and Fe(2+) with an aqueous NaOH solution. The Fe(3)O(4)/polyaniline (PANI) magnetic composite nanoparticles with a core-shell structure with a diameter of 30-50 nm were prepared via an in situ polymerization of aniline in an aqueous solution containing the Fe(3)O(4) magnetic fluid. The inductive heat property of Fe(3)O(4)/PANI composite nanoparticles in an alternating current (ac) magnetic field was investigated. The potential of Fe(3)O(4)/PANI nanoparticles was evaluated for localized hyperthermia treatment of cancers. The saturation magnetization, M(s), and coercivity, H(c), are 50.05 emu g(-1) and 137 Oe for Fe(3)O(4) nanoparticles and 26.34 emu g(-1) and 0 Oe for Fe(3)O(4)/PANI composite nanoparticles, respectively. Exposed in the ac magnetic field for 29 min, the temperatures of physiological saline suspensions containing Fe(3)O(4) nanoparticles or Fe(3)O(4)/PANI composite nanoparticles are 63.6 degrees C and 52.4 degrees C, respectively. The Fe(3)O(4)/PANI composite nanoparticles would be useful as good thermoseeds for localized hyperthermia treatment of cancers. PMID:18458406

  19. Optical fiber method for detection of single-phasing faults in three-phase induction motors used in underground mines

    NASA Astrophysics Data System (ADS)

    Kumar, Virendra; Chandra, Dinesh

    1998-09-01

    In this paper, a brief description of fiber optic based system for detection of single-phasing faults in 3-phase induction motors used in underground coal mines has been given. The system has an alarm facility which start sounding in absence of power. It also consists of three light emitting diodes of different colors to show the absence of power in a particular phase along with the alarm. Optical fiber, being a dielectric, non-metallic, and non-sparking is an intrinsically safe media and is ideally suited for single phasing faults detection of 3-phase motors used in underground mines or in any other hazardous environment.

  20. Gravitational search algorithm based tuning of a PI speed controller for an induction motor drive

    NASA Astrophysics Data System (ADS)

    Abd Ali, Jamal; Hannan, M. A.; Mohamed, Azah

    2016-03-01

    Proportional-integral (PI)-controller is very useful for controlling speed and mechanical load variables for the three-phase induction motor (TIM) operation. However, the conventional PI-controller has a very exhaustive trial and error procedure for obtaining it is parameters. In this paper, PI speed controller has been improved in it is design technique to suite TIM by utilizing a gravitational search algorithm (GSA) optimization technique. The mean absolute error (MAE) of the speed response has been used as an objective function. An optimal GSA based PI speed controller (GSA-PI) objective function is also employed to tune and minimize the MAE for developing the performance of the TIM in terms of changes speed and mechanical load. This experiment use space vector pulse width modulation (SVPWM) technique to create pulse width modulation for switching devices for three phase bridge inverter. Results obtained from the GSA-PI speed controller are compared with those obtained through particle swarm optimization (PSO) to validate the developed controller. Then it has been proved that the robustness of the GSA-PI speed controller is far better than that of the1 PSO controller in all tested cases in terms of damping capability and transient response under different mechanical loads and speeds.

  1. Measurement of position deviation and eccentricity for μ-disc-type inductive micro-motor

    NASA Astrophysics Data System (ADS)

    Lin, Chih-Che; Tsai, Nan-Chyuan

    2015-12-01

    An innovative capacitive gap-sensing readout circuit to replace traditional gap sensor is designed to measure the motion of the levitated micro-disc embedded in an inductive micro-motor. Twelve equivalent capacitor pairs are constructed to detect the position deviation of the disc. As the position deviation of disc occurs, the capacitances of the corresponding capacitor pairs are altered. In addition, by applying the effects of inertial force and centrifugal force, an innovative non-contact measurement method to quantify the unbalance degree of the micro-disc, i.e., eccentricity, is also proposed. By commercial computer simulations and realistic experiments undertaken, the performance of the proposed capacitive gap-sensing readout circuit has been successfully verified. The mean of output voltage of gap-sensing readout circuit is about 327 mV under the position deviation of the disc being 8 μm. Moreover, the unbalance degree of the disc is approximately proportional to the square of the position deviation of the disc.

  2. Fuzzy virtual reference model sensorless tracking control for linear induction motors.

    PubMed

    Hung, Cheng-Yao; Liu, Peter; Lian, Kuang-Yow

    2013-06-01

    This paper introduces a fuzzy virtual reference model (FVRM) synthesis method for linear induction motor (LIM) speed sensorless tracking control. First, we represent the LIM as a Takagi-Sugeno fuzzy model. Second, we estimate the immeasurable mover speed and secondary flux by a fuzzy observer. Third, to convert the speed tracking control into a stabilization problem, we define the internal desired states for state tracking via an FVRM. Finally, by solving a set of linear matrix inequalities (LMIs), we obtain the observer gains and the control gains where exponential convergence is guaranteed. The contributions of the approach in this paper are threefold: 1) simplified approach--speed tracking problem converted into stabilization problem; 2) omit need of actual reference model--FVRM generates internal desired states; and 3) unification of controller and observer design--control objectives are formulated into an LMI problem where powerful numerical toolboxes solve controller and observer gains. Finally, experiments are carried out to verify the theoretical results and show satisfactory performance both in transient response and robustness. PMID:23076069

  3. Superconductor-Mediated Modification of Gravity? AC Motor Experiments with Bulk YBCO Disks in Rotating Magnetic Fields

    NASA Technical Reports Server (NTRS)

    Noever, David A.; Koczor, Ronald J.; Roberson, Rick

    1998-01-01

    We have previously reported results using a high precision gravimeter to probe local gravity changes in the neighborhood of large bulk-processed high-temperature superconductors. Podkietnov, et al (Podkietnov, E. and Nieminen, R. (1992) A Possibility of Gravitational Force Shielding by Bulk YBa2 Cu3 O7-x Superconductor, Physica C, C203:441-444.) have indicated that rotating AC fields play an essential role in their observed distortion of combined gravity and barometric pressure readings. We report experiments on large (15 cm diameter) bulk YBCO ceramic superconductors placed in the core of a three-phase, AC motor stator. The applied rotating field produces up to a 12,000 revolutions per minute magnetic field. The field intensity decays rapidly from the maximum at the outer diameter of the superconducting disk (less than 60 Gauss) to the center (less than 10 Gauss). This configuration was applied with and without a permanent DC magnetic field levitating the superconducting disk, with corresponding gravity readings indicating an apparent increase in observed gravity of less than 1 x 10(exp -6)/sq cm, measured above the superconductor. No effect of the rotating magnetic field or thermal environment on the gravimeter readings or on rotating the superconducting disk was noted within the high precision of the observation. Implications for propulsion initiatives and power storage flywheel technologies for high temperature superconductors will be discussed for various spacecraft and satellite applications.

  4. Analysis of field-oriented controlled induction motor drives under sensor faults and an overview of sensorless schemes.

    PubMed

    Arun Dominic, D; Chelliah, Thanga Raj

    2014-09-01

    To obtain high dynamic performance on induction motor drives (IMD), variable voltage and variable frequency operation has to be performed by measuring speed of rotation and stator currents through sensors and fed back them to the controllers. When the sensors are undergone a fault, the stability of control system, may be designed for an industrial process, is disturbed. This paper studies the negative effects on a 12.5 hp induction motor drives when the field oriented control system is subjected to sensor faults. To illustrate the importance of this study mine hoist load diagram is considered as shaft load of the tested machine. The methods to recover the system from sensor faults are discussed. In addition, the various speed sensorless schemes are reviewed comprehensively. PMID:24981890

  5. A new viewpoint of end effect of linear induction motor from secondary side in ladder type model

    SciTech Connect

    Fujii, N.; Harada, T.

    1999-09-01

    In Japan, the subway trains driven by linear induction motors (LIMs) have been used in metropolitans of Tokyo and Osaka. As a new viewpoint, the physical phenomenon of end effect in ladder type linear induction motor (LIM) is observed from secondary side by making use of the structural feature. The phenomena in the ladder type and the sheet type LIM are the same fundamentally. The analytical method for the study is the special two-dimensional electromagnetic analysis, in which the current in each conducting bar is determined considering with time harmonics of secondary current. A new factor t{sub p}/t{sub s} is proposed to present the degree of end effect, in where t{sub p} is the passing duration of primary core at a secondary point and t{sub s} the half-period of slip frequency. The factor will be useful for the design grasping the essential of end effect of LIM.

  6. Experimental Study on a Voltage Source Inverter-fed Induction Motor Traction System Connected to Fuel Cell

    NASA Astrophysics Data System (ADS)

    Furuya, Takemasa; Kondo, Keiichiro; Yamamoto, Takamitsu

    This paper describes the experimental results of a test to drive two induction motors through a VVVF inverter by 25kW class proton membrane type fuel cells (PEMFCs). The experiments are aimed at verifying the compatibility between the drive system for the railway vehicle traction and FCs. This paper describes test results of powering, powering-off procedure, and simulated slip-readhesion control test, respectively. Through the experiments, we obtained useful knowledge required in designing the fuel cell drive system.

  7. ac propulsion system for an electric vehicle

    NASA Technical Reports Server (NTRS)

    Geppert, S.

    1980-01-01

    It is pointed out that dc drives will be the logical choice for current production electric vehicles (EV). However, by the mid-80's, there is a good chance that the price and reliability of suitable high-power semiconductors will allow for a competitive ac system. The driving force behind the ac approach is the induction motor, which has specific advantages relative to a dc shunt or series traction motor. These advantages would be an important factor in the case of a vehicle for which low maintenance characteristics are of primary importance. A description of an EV ac propulsion system is provided, taking into account the logic controller, the inverter, the motor, and a two-speed transmission-differential-axle assembly. The main barrier to the employment of the considered propulsion system in EV is not any technical problem, but inverter transistor cost.

  8. Comparison of experimental and theoretical reaction rail currents, rail voltages, and airgap fields for the linear induction motor research vehicle

    NASA Technical Reports Server (NTRS)

    Elliott, D. G.

    1977-01-01

    Measurements of reaction rail currents, reaction rail voltages, and airgap magnetic fields in tests of the Linear Induction Motor Research Vehicle (LIMRV) were compared with theoretical calculations from the mesh/matrix theory. It was found that the rail currents and magnetic fields predicted by the theory are within 20 percent of the measured currents and fields at most motor locations in most of the runs, but differ by as much as a factor of two in some cases. The most consistent difference is a higher experimental than theoretical magnetic field near the entrance of the motor and a lower experimental than theoretical magnetic field near the exit. The observed differences between the theoretical and experimental magnetic fields and currents do not account for the differences of as much as 26 percent between the theoretical and experimental thrusts.

  9. A Servo System of AC Motor Based on Voltage Modulation Fitting for FPGA and Consideration of Voltage Saturation

    NASA Astrophysics Data System (ADS)

    Takahashi, Kenji; Kanmachi, Tosiyuki; Ohishi, Kiyoshi

    This paper proposes a space voltage vector modulation (SVM) method for a speed servo system to obtain a quick current response. The proposed SVM method shortens the control lag time of the conventional SVM inverter. In addition, this proposed method is easily implemented of the hardware using a FPGA (Field Programmable Gate Array) because the proposed SVM equations is transformed into the expressions that hardly needs multiplication. By using the proposed SVM method, the servo system realizes a quick and stable current control with wide bandwidth. Moreover, by using PI controllers considering the voltage saturation and the torque limiter to the speed servo system, the servo system carries out a stable speed control on voltage saturation. Both the proposed SVM method and the PI controllers considering the voltage saturation are applied to a speed servo system of a vector controlled induction motor. The effectiveness of both the proposed SVM method and the PI controllers considering voltage saturation is verified by the experimental results.

  10. Advanced single permanent magnet axipolar ironless stator ac motor for electric passenger vehicles

    NASA Technical Reports Server (NTRS)

    Beauchamp, E. D.; Hadfield, J. R.; Wuertz, K. L.

    1983-01-01

    A program was conducted to design and develop an advanced-concept motor specifically created for propulsion of electric vehicles with increased range, reduced energy consumption, and reduced life-cycle costs in comparison with conventional systems. The motor developed is a brushless, dc, rare-earth cobalt, permanent magnet, axial air gap inductor machine that uses an ironless stator. Air cooling is inherent provided by the centrifugal-fan action of the rotor poles. An extensive design phase was conducted, which included analysis of the system performance versus the SAE J227a(D) driving cycle. A proof-of-principle model was developed and tested, and a functional model was developed and tested. Full generator-level testing was conducted on the functional model, recording electromagnetic, thermal, aerodynamic, and acoustic noise data. The machine demonstrated 20.3 kW output at 1466 rad/s and 160 dc. The novel ironless stator demonstated the capability to continuously operate at peak current. The projected system performance based on the use of a transistor inverter is 23.6 kW output power at 1466 rad/s and 83.3 percent efficiency. Design areas of concern regarding electric vehicle applications include the inherently high windage loss and rotor inertia.

  11. A survey on time and frequency characteristics of induction motors with broken rotor bars in line-start and inverter-fed modes

    NASA Astrophysics Data System (ADS)

    Ghorbanian, Vahid; Faiz, Jawad

    2015-03-01

    This paper deals with the comprehensive detailed concepts of the rotor broken bars fault in industrial induction motors. It reviews the most important and applicable techniques for fault detection, and addresses fault diagnosing procedures at different supply modes including line-start and inverter-fed modes. Moreover, new analytical and experimental aspects of fault are proposed using the time and frequency domain variations of the motor variables such as current, voltage, electromagnetic torque and speed. Since the faulty motor behavior cannot be correctly identified without considering the motor operating condition, and the capability of the previous fault indicators are studied deeply in order to investigate their applicability at different conditions. These conditions include various faults, load and reference speed levels and also fault location. All in all, a precise condition assessment of the rotor broken bar induction motors, suitable for industrial purposes, is presented considering motor supply and conditions changes.

  12. New Energy-Saving Technologies Use Induction Generators

    NASA Technical Reports Server (NTRS)

    Nola, F.

    1982-01-01

    Two energy-saving technologies tested recently at Marshall Space Flight Center use an induction motor operated in reverse (as an induction generator). In the first, energy ordinarily dissipated during load testing of machinery is recovered and returned to powerline. In the second, efficiency of wind-driven induction generator is improved, and useful range of windspeed is broadened. Both technologies take advantage of ac voltage developed across terminals of an induction motor when rotated at higher than-synchronous speed in the direction it normally turns when power is appled.

  13. Mixed eccentricity diagnosis in Inverter-Fed Induction Motors via the Adaptive Slope Transform of transient stator currents

    NASA Astrophysics Data System (ADS)

    Pons-Llinares, J.; Antonino-Daviu, J.; Roger-Folch, J.; Moríñigo-Sotelo, D.; Duque-Pérez, O.

    2014-10-01

    This paper researches the detection of mixed eccentricity in Inverter-Fed Induction Motors. The classic FFT method cannot be applied when the stator current captured is not in steady state, which is very common in these motors. Therefore, a transform able to detect the time-frequency evolutions of the components present in the transient signal captured must be applied. In order to optimize the result, a method to calculate the theoretical time-frequency evolution of the stator current components is presented, using only the captured current. This previously obtained information enables the use of the proposed transform: the Adaptive Slope Transform, based on appropriately choosing the atom slope in each point analyzed. Thanks to its adaptive characteristics, the time-frequency evolution of the main components in a stator transient current is traced precisely and with high detail in the 2D time-frequency plot obtained. As a consequence, the time-frequency plane characteristic patterns produced by the Eccentricity Related Harmonics are easily and clearly identified enabling a reliable diagnosis. Moreover, the problem of quantifying the presence of the fault is solved presenting a simple and easy to apply method. The transform capabilities have been shown successfully diagnosing an Inverter-Fed Induction Motor with mixed eccentricity during a startup, a decrease in the assigned frequency, and a load variation with and without slip compensation.

  14. Automatic fault feature extraction of mechanical anomaly on induction motor bearing using ensemble super-wavelet transform

    NASA Astrophysics Data System (ADS)

    He, Wangpeng; Zi, Yanyang; Chen, Binqiang; Wu, Feng; He, Zhengjia

    2015-03-01

    Mechanical anomaly is a major failure type of induction motor. It is of great value to detect the resulting fault feature automatically. In this paper, an ensemble super-wavelet transform (ESW) is proposed for investigating vibration features of motor bearing faults. The ESW is put forward based on the combination of tunable Q-factor wavelet transform (TQWT) and Hilbert transform such that fault feature adaptability is enabled. Within ESW, a parametric optimization is performed on the measured signal to obtain a quality TQWT basis that best demonstrate the hidden fault feature. TQWT is introduced as it provides a vast wavelet dictionary with time-frequency localization ability. The parametric optimization is guided according to the maximization of fault feature ratio, which is a new quantitative measure of periodic fault signatures. The fault feature ratio is derived from the digital Hilbert demodulation analysis with an insightful quantitative interpretation. The output of ESW on the measured signal is a selected wavelet scale with indicated fault features. It is verified via numerical simulations that ESW can match the oscillatory behavior of signals without artificially specified. The proposed method is applied to two engineering cases, signals of which were collected from wind turbine and steel temper mill, to verify its effectiveness. The processed results demonstrate that the proposed method is more effective in extracting weak fault features of induction motor bearings compared with Fourier transform, direct Hilbert envelope spectrum, different wavelet transforms and spectral kurtosis.

  15. Direct Torque Control with Full Order Stator Flux Observer for Dual-Three Phase Induction Motor Drives

    NASA Astrophysics Data System (ADS)

    Farina, Francesco; Bojoi, Radu; Tenconi, Alberto; Profumo, Francesco

    A Direct Torque Control (DTC) strategy for dual-three phase induction motor drives is discussed in this paper. The induction machine has two sets of stator three-phase windings spatially shifted by 30 electrical degrees with isolated neutral points. The proposed control strategy is based on Proportional Integral (PI) regulators implemented in the stator flux synchronous reference frame. To improve the flux estimation, an Adaptive Stator Flux Observer (ASFO) has been used. Doing so, besides a better flux estimation in contrast to open-loop flux estimators, it is possible to use the observed currents to compensate the inverter non-linear behavior (such as dead-time effects), improving the drive performance at low speed. This is particularly important for low voltage/high current applications, as the drive considered in this paper. The advantages of the discussed control strategy are: constant inverter switching frequency, good transient and steady-state performance and less distorted machine currents in contrast to DTC schemes with variable switching frequency. Experimental results are presented for a 10kW dual three-phase induction motor drive prototype.

  16. The Design and its Verification of the Double Rotor Double Cage Induction Motor

    NASA Astrophysics Data System (ADS)

    Sinha, Sumita; Deb, Nirmal K.; Biswas, Sujit K.

    2016-06-01

    The concept of a double rotor motor presented earlier and its equivalent circuit has been developed, showing a non-linear parameter content. The two rotors (which are recommended to be double cage type for development of high starting torque) can run with equal or unequal speed independently, depending on their individual loading. This paper presents the elaborate design procedure, step-by-step, for the double rotor double cage motor and verifies the designed data with that obtained from three separate tests (compared to two for conventional motor) on a prototype, such that optimum performance can be obtained from the motor.

  17. Performance Evaluation and Slip Regulation Control of an Asymmetrical Parameter Type Two-Phase Induction Motor Drive Using a Three-Leg Voltage Source Inverter

    NASA Astrophysics Data System (ADS)

    Piyarat, Wekin; Kinnares, Vijit

    This paper presents a performance evaluation and a simple speed control method of an asymmetrical parameter type two-phase induction motor drive using a three-leg VSI (Voltage Source Inverter). The two-phase induction motor is adapted from an existing single-phase induction motor resulting in impedance unbalance between main and auxiliary windings. The unbalanced two-phase inverter outputs with orthogonal displacement based on a SPWM (Sinusoidal Pulse Width Modulation) method are controlled with appropriate amplitudes for improving the motor performance. Dynamic simulation of the proposed drive system is given. A simple speed controller based on a slip regulation method is designed. The overall system is implemented on a DSP (Digital Signal Processor) board. The validity of the proposed system is verified by simulation and experimental results.

  18. Proposal of new structure of MgB 2 wires with low AC loss for stator windings of fully superconducting motors located in iron core slots

    NASA Astrophysics Data System (ADS)

    Kajikawa, K.; Osaka, R.; Kuga, H.; Nakamura, T.; Wakuda, T.

    2011-11-01

    The new structure of MgB 2 monofilamentary wires for stator windings of fully superconducting motors is proposed to reduce their AC losses in iron core slots for the application of an alternating transport current. In order to validate the proposed structure of wire for loss reduction, numerical calculations are carried out by means of a finite element method using edge elements formulated with a self-field due to currents induced in an analysis region. It is assumed that the voltage-current characteristics of the MgB 2 superconductor are given by Bean’s critical state model, in which the critical current density is independent of the local magnetic field. The influences of wire structures on the AC losses are discussed quantitatively toward the optimum design of stator windings in fully superconducting motors with the MgB 2 wires.

  19. Phase-sensitive inductive detection of ac currents due to spin-pumping/inverse spin Hall effect in unpatterned Permalloy/Pt bilayers

    NASA Astrophysics Data System (ADS)

    Silva, Thomas; Nembach, Hans; Shaw, Justin; Karenowska, Alexy; Weiler, Mathias

    We present a new method to measure the ac inverse spin Hall effect at GHz frequencies. Unlike previous methods, our does not rely on any patterning or electrical contacts. We utilize phase-sensitive, broad-band, perpendicular-field ferromagnetic resonance to detect the ac current by the inverse spin Hall effect (iSHE) in Py/Pt bilayers. The iSHE component of the signal is non-linear in the excitation frequency; while the inductive FMR response scales linearly with frequency, the iSHE signal scales quadratically because the iSHE current itself is proportional to dm/dt. This differential gain affords us detection of previously unreported higher order contributions to the iSHE signal. We compare FMR measurements with a control samples that do not include the high spin-orbit layer, e.g. Pt. Data sets with and without Pt are normalized by the complex Polder susceptibility, which nullifies any effects due to differences in line-width and anisotropy. The complex ratio of the normalized inductive amplitudes is analyzed with a simple model that considers how the ac currents generated by the iSHE couple inductively back into the excitations waveguide. The linear iSHE signal agrees with previous reported values. The nonlinear iSHE signal is 3-4 orders of magnitude weaker, but is easily detected over the frequency range of 5-45 GHz

  20. Application of power spectrum, cepstrum, higher order spectrum and neural network analyses for induction motor fault diagnosis

    NASA Astrophysics Data System (ADS)

    Liang, B.; Iwnicki, S. D.; Zhao, Y.

    2013-08-01

    The power spectrum is defined as the square of the magnitude of the Fourier transform (FT) of a signal. The advantage of FT analysis is that it allows the decomposition of a signal into individual periodic frequency components and establishes the relative intensity of each component. It is the most commonly used signal processing technique today. If the same principle is applied for the detection of periodicity components in a Fourier spectrum, the process is called the cepstrum analysis. Cepstrum analysis is a very useful tool for detection families of harmonics with uniform spacing or the families of sidebands commonly found in gearbox, bearing and engine vibration fault spectra. Higher order spectra (HOS) (also known as polyspectra) consist of higher order moment of spectra which are able to detect non-linear interactions between frequency components. For HOS, the most commonly used is the bispectrum. The bispectrum is the third-order frequency domain measure, which contains information that standard power spectral analysis techniques cannot provide. It is well known that neural networks can represent complex non-linear relationships, and therefore they are extremely useful for fault identification and classification. This paper presents an application of power spectrum, cepstrum, bispectrum and neural network for fault pattern extraction of induction motors. The potential for using the power spectrum, cepstrum, bispectrum and neural network as a means for differentiating between healthy and faulty induction motor operation is examined. A series of experiments is done and the advantages and disadvantages between them are discussed. It has been found that a combination of power spectrum, cepstrum and bispectrum plus neural network analyses could be a very useful tool for condition monitoring and fault diagnosis of induction motors.

  1. Sliding-mode control of a six-phase series/parallel connected two induction motors drive.

    PubMed

    Abjadi, Navid R

    2014-11-01

    In this paper, a parallel configuration is proposed for two quasi six-phase induction motors (QIMs) to feed them from a single six-phase voltage source inverter (VSI). A direct torque control (DTC) based on input-output feedback linearization (IOFL) combined with sliding mode (SM) control is used for each QIM in stationary reference frame. In addition, an adaptive scheme is employed to solve the motor resistances mismatching problem. The effectiveness and capability of the proposed method are shown by practical results obtained for two QIMs in series/parallel connections supplied from a single VSI. The decoupling control of QIMs and the feasibility of their torque and flux control are investigated. Moreover, a complete comparison between series and parallel connections of two QIMs is given. PMID:25264286

  2. The impact of different stator and rotor slot number combinations on iron losses of a three-phase induction motor at no-load

    NASA Astrophysics Data System (ADS)

    Marčič, T.; Štumberger, B.; Štumberger, G.; Hadžiselimović, M.; Zagradišnik, I.

    The electromechanical characteristics of induction motors depend on the used stator and rotor slot combination. The correlation between the usage of different stator and rotor slot number combinations, magnetic flux density distributions, no-load iron losses and rated load winding over-temperatures for a specific induction motor is presented. The motor's magnetic field was analyzed by traces of the magnetic flux density vector, obtained by FEM. Post-processing of FE magnetic field solution was used for posterior iron loss calculation of the motor iron loss at no-load. The examined motor stator lamination had 36 semi-closed slots and the rotor laminations had 28, 33, 34, 44 and 46 semi-closed slots.

  3. A fuzzy-based approach for open-transistor fault diagnosis in voltage-source inverter induction motor drives

    NASA Astrophysics Data System (ADS)

    Zhang, Jianghan; Luo, Hui; Zhao, Jin; Wu, Feng

    2015-02-01

    This paper develops a novel method for the detection and isolation of open-transistor faults in voltage-source inverters feeding induction motors. Based on analyzing the load currents trajectories after Concordia transformation, six diagnostic signals each of which indicates a certain switch are extracted and a fuzzy rule base is designed to perform fuzzy reasoning in order to detect and isolate 21 fault modes including single- and double-transistor faults. In addition, the fuzzy rules are rearranged and each of them is set to a reasonable value representing the fault modes. The simulation and experiment are carried out to demonstrate the effectiveness of the proposed fuzzy approach.

  4. An investigation on the characteristics of a single-sided linear induction motor at standstill for maglev vehicles

    SciTech Connect

    Cho, Y.; Lee, J.

    1997-03-01

    This paper presents the single-sided linear induction motor (SLIM) developed as electrical drives for magnetic levitation vehicle with a cruising speed 40--100Km/h for EXPO`93 in Taejon, Korea. The SLIM is designed to produce a 2,440 Newtons thrust from an active area of 2,836mm long by 235 mm wide at the airgap of 14 mm. In order to investigate its performance characteristics both experimentally and theoretically, the static test facilities was designed and equipped. At standstill, the experimental results are compared with the analytical ones.

  5. Q-Axis Flux-Based Sensorless Vector Control of Induction Motor Taking into Account Iron Loss

    NASA Astrophysics Data System (ADS)

    Tsuji, Mineo; Chen, Shuo; Kai, Toshihiro; Hamasaki, Shin-Ichi

    This paper presents a sensorless vector control system for induction motors by taking into account iron loss, in which a flux-observer-based method is applied. Since the flux observer is constructed in a synchronously rotating reference frame with respect to the rotor flux of a current model and the iron loss resistance of parallel exiting circuit is used, the proposed system is very simple and the compensation of iron loss related to the operating frequency is directly realized while calculating rotor fluxes and slip frequency. The accuracies of estimated torque and speed are improved. The effectiveness of the proposed system has been verified by digital simulation and experimentation.

  6. Torsional Vibration Analysis of Reciprocating Compressor Trains driven by Induction Motors

    NASA Astrophysics Data System (ADS)

    Brunelli, M.; Fusi, A.; Grasso, F.; Pasteur, F.; Ussi, A.

    2015-08-01

    The dynamic study of electric motor driven compressors, for Oil&Gas (O&G) applications, are traditionally performed in two steps separating the mechanical and the electrical systems. The packager conducts a Torsional Vibration Analysis (TVA) modeling the mechanical system with a lumped parameter scheme, without taking into account the electrical part. The electric motor supplier later performs a source current pulsation analysis on the electric motor system, based on the TVA results. The mechanical and the electrical systems are actually linked by the electromagnetic effect. The effect of the motor air-gap on TVA has only recently been taken into account by adding a spring and a damper between motor and ground in the model. This model is more accurate than the traditional one, but is applicable only to the steady-state condition and still fails to consider the reciprocal effects between the two parts of the system. In this paper the torsional natural frequencies calculated using both the traditional and the new model have been compared. Furthermore, simulation of the complete system has been achieved through the use of LMS AMESim, multi-physics, one-dimensional simulation software that simultaneously solves the shafts rotation and electric motor voltage equation. Finally, the transient phenomena that occur during start-up have been studied.

  7. Sensored Field Oriented Control of a Robust Induction Motor Drive Using a Novel Boundary Layer Fuzzy Controller

    PubMed Central

    Saghafinia, Ali; Ping, Hew Wooi; Uddin, Mohammad Nasir

    2013-01-01

    Physical sensors have a key role in implementation of real-time vector control for an induction motor (IM) drive. This paper presents a novel boundary layer fuzzy controller (NBLFC) based on the boundary layer approach for speed control of an indirect field-oriented control (IFOC) of an induction motor (IM) drive using physical sensors. The boundary layer approach leads to a trade-off between control performances and chattering elimination. For the NBLFC, a fuzzy system is used to adjust the boundary layer thickness to improve the tracking performance and eliminate the chattering problem under small uncertainties. Also, to eliminate the chattering under the possibility of large uncertainties, the integral filter is proposed inside the variable boundary layer. In addition, the stability of the system is analyzed through the Lyapunov stability theorem. The proposed NBLFC based IM drive is implemented in real-time using digital signal processor (DSP) board TI TMS320F28335. The experimental and simulation results show the effectiveness of the proposed NBLFC based IM drive at different operating conditions.

  8. On the evolution of ac machines for spindle drive applications

    SciTech Connect

    Fratta, A.; Vagati, A.; Villata, F. )

    1992-10-01

    In the field of ac spindle drives, the induction motor is widely adopted. Synchronous solutions (reluctance, interior permanent magnets) are often suggested to overcome some drawbacks of the induction motor. This paper compares the different options by considering the machine torque-density and the inverter power size needed for a given constant-power speed range. It is shown that an axially laminated reluctance motor gives more torque density than the induction motor but nearly requires the same inverter size. By adding a proper quantity of permanent magnets, the inverter size can be greatly reduced. A comprehensive discussion is made on this subject, aiming to point out a design solution that is 'optimal' for the whole drive.

  9. The ac propulsion system for an electric vehicle, phase 1

    NASA Technical Reports Server (NTRS)

    Geppert, S.

    1981-01-01

    A functional prototype of an electric vehicle ac propulsion system was built consisting of a 18.65 kW rated ac induction traction motor, pulse width modulated (PWM) transistorized inverter, two speed mechanically shifted automatic transmission, and an overall drive/vehicle controller. Design developmental steps, and test results of individual components and the complex system on an instrumented test frame are described. Computer models were developed for the inverter, motor and a representative vehicle. A preliminary reliability model and failure modes effects analysis are given.

  10. Characteristic and magnetic field analysis of a high temperature superconductor axial-flux coreless induction maglev motor

    NASA Astrophysics Data System (ADS)

    Wei, Qin; Yu, Fan; Jin, Fang; Shuo, Li; Guoguo, Li; Gang, Lv

    2012-04-01

    A new high temperature superconductor axial-flux coreless maglev motor (HTS AFIM) is proposed, of which the primary windings are made of HTS tapes and the secondary is a non-magnetic conductor. The main works of this paper are the magnetic-field computation and characteristics analysis of HTS AFIM. For the first one, the reduction of magnetic fields near outer and inner radius of the HTS AFIM is solved by introducing the sub-loop electro-magnetic model along the radial position. For the second one, the AC losses of HTS coils are calculated. The relationships between the device's characteristics and device parameters are presented, and the results indicate that under certain frequency and current levitation device can output enough lift force. The conclusions are verified by finite element calculations.

  11. Characteristic and magnetic field analysis of a high temperature superconductor axial-flux coreless induction maglev motor.

    PubMed

    Wei, Qin; Yu, Fan; Jin, Fang; Shuo, Li; Guoguo, Li; Gang, Lv

    2012-04-01

    A new high temperature superconductor axial-flux coreless maglev motor (HTS AFIM) is proposed, of which the primary windings are made of HTS tapes and the secondary is a non-magnetic conductor. The main works of this paper are the magnetic-field computation and characteristics analysis of HTS AFIM. For the first one, the reduction of magnetic fields near outer and inner radius of the HTS AFIM is solved by introducing the sub-loop electro-magnetic model along the radial position. For the second one, the AC losses of HTS coils are calculated. The relationships between the device's characteristics and device parameters are presented, and the results indicate that under certain frequency and current levitation device can output enough lift force. The conclusions are verified by finite element calculations. PMID:22393268

  12. Characteristic and magnetic field analysis of a high temperature superconductor axial-flux coreless induction maglev motor

    PubMed Central

    Wei, Qin; Yu, Fan; Jin, Fang; Shuo, Li; Guoguo, Li; Gang, Lv

    2012-01-01

    A new high temperature superconductor axial-flux coreless maglev motor (HTS AFIM) is proposed, of which the primary windings are made of HTS tapes and the secondary is a non-magnetic conductor. The main works of this paper are the magnetic-field computation and characteristics analysis of HTS AFIM. For the first one, the reduction of magnetic fields near outer and inner radius of the HTS AFIM is solved by introducing the sub-loop electro-magnetic model along the radial position. For the second one, the AC losses of HTS coils are calculated. The relationships between the device’s characteristics and device parameters are presented, and the results indicate that under certain frequency and current levitation device can output enough lift force. The conclusions are verified by finite element calculations. PMID:22393268

  13. Characterization and snubbing of a bidirectional MCT in a resonant ac link converter

    NASA Technical Reports Server (NTRS)

    Lee, Tony; Elbuluk, Malik E.; Zinger, Donald S.

    1993-01-01

    The MOS-Controlled Thyristor (MCT) is emerging as a powerful switch that combines the better characteristics of existing power devices. A study of switching stresses on an MCT switch under zero voltage resonant switching is presented. The MCT is used as a bidirectional switch in an ac/ac pulse density modulated inverter for induction motor drive. Current and voltage spikes are observed and analyzed with variations in the timing of the switching. Different snubber circuit configurations are under investigation to minimize the effect of these transients. The results will be extended to study and test the MCT switching in a medium power (5 hp) induction motor drive.

  14. Detection of the Short-Circuit Faults in the Stator Winding of Induction Motors based on Harmonics of the Neighboring Magnetic Field

    NASA Astrophysics Data System (ADS)

    Fireteanu, V.

    2013-06-01

    Based on the time domain finite element analysis of the electromagnetic field, this paper studies the signature of the short-circuit faults inside the stator winding in the magnetic field outside induction motors. The detection of the such a fault is based on the evaluation of the output voltage of coil sensors placed in the motors neighbouring and the comparison of amplitudes of harmonics of this voltage for the healthy and faulty operation states.

  15. Continuous delivery of ropinirole reverses motor deficits without dyskinesia induction in MPTP-treated common marmosets.

    PubMed

    Stockwell, K A; Virley, D J; Perren, M; Iravani, M M; Jackson, M J; Rose, S; Jenner, P

    2008-05-01

    L-DOPA treatment of Parkinson's disease induces a high incidence of motor complications, notably dyskinesia. Longer acting dopamine agonists, e.g. ropinirole, are thought to produce more continuous dopaminergic stimulation and less severe dyskinesia. However, standard oral administration of dopamine agonists does not result in constant plasma drug levels, therefore, more continuous drug delivery may result in both prolonged reversal of motor deficits and reduced levels of dyskinesia. Therefore, we compared the effects of repeated oral administration of ropinirole to constant subcutaneous infusion in MPTP-treated common marmosets. Animals received oral administration (0.4 mg/kg, BID) or continuous infusion of ropinirole (0.8 mg/kg/day) via osmotic minipumps for 14 days (Phase I). The treatments were then switched and continued for a further 14 days (Phase II). In Phase I, locomotor activity was similar between treatment groups but reversal of motor disability was more pronounced in animals receiving continuous infusion. Dyskinesia intensity was low in both groups however there was a trend suggestive of less marked dyskinesia in those animals receiving continuous infusion. In Phase II, increased locomotor activity was maintained but animals switched from oral to continuous treatment showing an initial period of enhanced locomotor activity. The reversal of motor disability was maintained in both groups, however, motor disability tended towards greater improvement following continuous infusion. Importantly, dyskinesia remained low in both groups suggesting that constant delivery of ropinirole neither leads to priming nor expression of dyskinesia. These results suggest that a once-daily controlled-release formulation may provide improvements over existing benefits with standard oral ropinirole in Parkinson's disease patients. PMID:18321484

  16. Harmonic reduction of Direct Torque Control of six-phase induction motor.

    PubMed

    Taheri, A

    2016-07-01

    In this paper, a new switching method in Direct Torque Control (DTC) of a six-phase induction machine for reduction of current harmonics is introduced. Selecting a suitable vector in each sampling period is an ordinal method in the ST-DTC drive of a six-phase induction machine. The six-phase induction machine has 64 voltage vectors and divided further into four groups. In the proposed DTC method, the suitable voltage vectors are selected from two vector groups. By a suitable selection of two vectors in each sampling period, the harmonic amplitude is decreased more, in and various comparison to that of the ST-DTC drive. The harmonics loss is greater reduced, while the electromechanical energy is decreased with switching loss showing a little increase. Spectrum analysis of the phase current in the standard and new switching table DTC of the six-phase induction machine and determination for the amplitude of each harmonics is proposed in this paper. The proposed method has a less sampling time in comparison to the ordinary method. The Harmonic analyses of the current in the low and high speed shows the performance of the presented method. The simplicity of the proposed method and its implementation without any extra hardware is other advantages of the proposed method. The simulation and experimental results show the preference of the proposed method. PMID:26948989

  17. Detection of a static eccentricity fault in a closed loop driven induction motor by using the angular domain order tracking analysis method

    NASA Astrophysics Data System (ADS)

    Akar, Mehmet

    2013-01-01

    In this study, a new method was presented for the detection of a static eccentricity fault in a closed loop operating induction motor driven by inverter. Contrary to the motors supplied by the line, if the speed and load, and therefore the amplitude and frequency, of the current constantly change then this also causes a continuous change in the location of fault harmonics in the frequency spectrum. Angular Domain Order Tracking analysis (AD-OT) is one of the most frequently used fault diagnosis methods in the monitoring of rotating machines and the analysis of dynamic vibration signals. In the presented experimental study, motor phase current and rotor speed were monitored at various speeds and load levels with a healthy and static eccentricity fault in the closed loop driven induction motor with vector control. The AD-OT method was applied to the motor current and the results were compared with the traditional FFT and Fourier Transform based Order Tracking (FT-OT) methods. The experimental results demonstrate that AD-OT method is more efficient than the FFT and FT-OT methods for fault diagnosis, especially while the motor is operating run-up and run-down. Also the AD-OT does not incur any additional cost for the user because in inverter driven systems, current and speed sensor coexist in the system. The main innovative parts of this study are that AD-OT method was implemented on the motor current signal for the first time.

  18. Support vector machine based decision for mechanical fault condition monitoring in induction motor using an advanced Hilbert-Park transform.

    PubMed

    Ben Salem, Samira; Bacha, Khmais; Chaari, Abdelkader

    2012-09-01

    In this work we suggest an original fault signature based on an improved combination of Hilbert and Park transforms. Starting from this combination we can create two fault signatures: Hilbert modulus current space vector (HMCSV) and Hilbert phase current space vector (HPCSV). These two fault signatures are subsequently analysed using the classical fast Fourier transform (FFT). The effects of mechanical faults on the HMCSV and HPCSV spectrums are described, and the related frequencies are determined. The magnitudes of spectral components, relative to the studied faults (air-gap eccentricity and outer raceway ball bearing defect), are extracted in order to develop the input vector necessary for learning and testing the support vector machine with an aim of classifying automatically the various states of the induction motor. PMID:22742760

  19. DSP-based adaptive backstepping using the tracking errors for high-performance sensorless speed control of induction motor drive.

    PubMed

    Zaafouri, Abderrahmen; Ben Regaya, Chiheb; Ben Azza, Hechmi; Châari, Abdelkader

    2016-01-01

    This paper presents a modified structure of the backstepping nonlinear control of the induction motor (IM) fitted with an adaptive backstepping speed observer. The control design is based on the backstepping technique complemented by the introduction of integral tracking errors action to improve its robustness. Unlike other research performed on backstepping control with integral action, the control law developed in this paper does not propose the increase of the number of system state so as not increase the complexity of differential equations resolution. The digital simulation and experimental results show the effectiveness of the proposed control compared to the conventional PI control. The results analysis shows the characteristic robustness of the adaptive control to disturbances of the load, the speed variation and low speed. PMID:26653141

  20. Fast Fourier and discrete wavelet transforms applied to sensorless vector control induction motor for rotor bar faults diagnosis.

    PubMed

    Talhaoui, Hicham; Menacer, Arezki; Kessal, Abdelhalim; Kechida, Ridha

    2014-09-01

    This paper presents new techniques to evaluate faults in case of broken rotor bars of induction motors. Procedures are applied with closed-loop control. Electrical and mechanical variables are treated using fast Fourier transform (FFT), and discrete wavelet transform (DWT) at start-up and steady state. The wavelet transform has proven to be an excellent mathematical tool for the detection of the faults particularly broken rotor bars type. As a performance, DWT can provide a local representation of the non-stationary current signals for the healthy machine and with fault. For sensorless control, a Luenberger observer is applied; the estimation rotor speed is analyzed; the effect of the faults in the speed pulsation is compensated; a quadratic current appears and used for fault detection. PMID:25004798

  1. Local Voltage Support from Distributed Energy Resources to Prevent Air Conditioner Motor Stalling

    SciTech Connect

    Baone, Chaitanya A; Xu, Yan; Kueck, John D

    2010-01-01

    Microgrid voltage collapse often happens when there is a high percentage of low inertia air-conditioning (AC) motors in the power systems. The stalling of the AC motors results in Fault Induced Delayed Voltage Recovery (FIDVR). A hybrid load model including typical building loads, AC motor loads, and other induction motor loads is built to simulate the motoring stalling phenomena. Furthermore, distributed energy resources (DE) with local voltage support capability are utilized to boost the local bus voltage during a fault, and prevent the motor stalling. The simulation results are presented. The analysis of the simulation results show that local voltage support from multiple DEs can effectively and economically solve the microgrid voltage collapse problem.

  2. Reluctance and doubly-excited reluctance motors

    NASA Astrophysics Data System (ADS)

    Heyne, C. J.; El-Antably, A. M.

    1984-11-01

    Since the energy crisis in 1974, there was increasing awareness of conserving energy. Industrial ac motors from 1 to 125 hp are estimated to consume 60% of the total electricity produced in the United States. Significant energy conservation could be achieved if the efficiency of these motors is improved. The work described was sponsored by the Division of Electric Energy Systems (EES) of the United States Department of Energy (DOE) through a subcontract with the Power Systems Technology Program at the Oak Ridge National Laboratory (Oak Ridge, Tennessee, USA). The design, analysis, and test of two types of motors designed to have a high efficiency and power factor are described. The first type, reluctance motors (RMs), are similar to synchronous motors but without dc excitation. A novel 3-phase RM was designed and tested, and it was found to have superior efficiency when compared with a similar induction motor.

  3. Reluctance and doubly-excited reluctance motors

    SciTech Connect

    Heyne, C.J.; El-Antably, A.M.

    1984-11-01

    Since the energy crisis in 1974, there has been increasing awareness of conserving energy. Industrial ac motors from 1 to 125 hp are estimated to consume 60% of the total electricity produced in the United States. Significant energy conservation could be achieved if the efficiency of these motors is improved. The work described in this report was sponsored by the Division of Electric Energy Systems (EES) of the United States Department of Energy (DOE) through a subcontract with the Power Systems Technology Program at the Oak Ridge National Laboratory (Oak Ridge, Tennessee, USA). This work deals with the design, analysis, and test of two types of motors designed to have a high efficiency and power factor. The first type, reluctance motors (RMs), are similar to synchronous motors but without dc excitation. A novel 3-phase RM has been designed and tested, and it was found to have superior efficiency when compared with a similar induction motor.

  4. Sliding mode pulse-width modulation technique for direct torque controlled induction motor drive

    NASA Astrophysics Data System (ADS)

    Bounadja, M.; Belarbi, A. W.; Belmadani, B.

    2010-05-01

    This paper presents a novel pulse-width modulation technique based sliding mode approach for direct torque control of an induction machine drive. Methodology begins with a sliding mode control of machine's torque and stator flux to generate the reference voltage vector and to reduce parameters sensitivity. Then, the switching control of the three-phase inverter is developed using sliding mode concept to make the system tracking reference voltage inputs. The main features of the proposed methodologies are the high tracking accuracy and the much easier implementation compared to the space vector modulation. Simulations are carried out to confirm the effectiveness of proposed control algorithms.

  5. Induction of phase 3 of the migrating motor complex in human small intestine by trimebutine.

    PubMed

    Chaussade, S; Grandjouan, S; Couturier, D; Thierman-Duffaud, D; Henry, J F

    1987-01-01

    The effects of trimebutine, a drug used in the treatment of various gastrointestinal motility disorders, have been investigated fed and fasted healthy subjects. Duodenojejunal motility was recorded manometrically with a 4-lumen probe. Trimebutine 50 or 100 mg was injected i.v. 3 or 25 min after observing a spontaneous Phase 3 complex in the fasted state. Other experiments were done in the postprandial state and after intravenous naloxone 0.8 mg. In the fasted state, trimebutine 100 mg, injected 25 min after a spontaneous Phase 3 complex consistently induced a premature Phase 3 complex. The mean duration of the migrating motor complex cycle decreased from 86.4 +/- 10.8 min to 32.5 +/- 1.0 min. Trimebutine 50 mg injected 3 and 25 min after a spontaneous Phase 3 complex did not significantly modify the periodicity of the migrating motor complex. Trimebutine 100 mg initiated Phase 3-like activity in the post-prandial state. Previous intravenous administration of naloxone 0.8 mg (Narcan) suppressed the stimulatory action of TMB. Thus, trimebutine is able to modify the motility pattern in the small intestine of man, possibly by acting at opioid receptors. PMID:2820749

  6. Comparisons between designs for single-sided linear electric motors: Homopolar synchronous and induction

    NASA Astrophysics Data System (ADS)

    Nondahl, T. A.; Richter, E.

    1980-09-01

    A design study of two types of single sided (with a passive rail) linear electric machine designs, namely homopolar linear synchronous machines (LSM's) and linear induction machines (LIM's), is described. It is assumed the machines provide tractive effort for several types of light rail vehicles and locomotives. These vehicles are wheel supported and require tractive powers ranging from 200 kW to 3735 kW and top speeds ranging from 112 km/hr to 400 km/hr. All designs are made according to specified magnetic and thermal criteria. The LSM advantages are a higher power factor, much greater restoring forces for track misalignments, and less track heating. The LIM advantages are no need to synchronize the excitation frequency precisely to vehicle speed, simpler machine construction, and a more easily anchored track structure. The relative weights of the two machine types vary with excitation frequency and speed; low frequencies and low speeds favor the LSM.

  7. The sensory-motor theory of rhythm and beat induction 20 years on: a new synthesis and future perspectives.

    PubMed

    Todd, Neil P M; Lee, Christopher S

    2015-01-01

    Some 20 years ago Todd and colleagues proposed that rhythm perception is mediated by the conjunction of a sensory representation of the auditory input and a motor representation of the body (Todd, 1994a, 1995), and that a sense of motion from sound is mediated by the vestibular system (Todd, 1992a, 1993b). These ideas were developed into a sensory-motor theory of rhythm and beat induction (Todd et al., 1999). A neurological substrate was proposed which might form the biological basis of the theory (Todd et al., 2002). The theory was implemented as a computational model and a number of experiments conducted to test it. In the following time there have been several key developments. One is the demonstration that the vestibular system is primal to rhythm perception, and in related work several experiments have provided further evidence that rhythm perception is body dependent. Another is independent advances in imaging, which have revealed the brain areas associated with both vestibular processing and rhythm perception. A third is the finding that vestibular receptors contribute to auditory evoked potentials (Todd et al., 2014a,b). These behavioral and neurobiological developments demand a theoretical overview which could provide a new synthesis over the domain of rhythm perception. In this paper we suggest four propositions as the basis for such a synthesis. (1) Rhythm perception is a form of vestibular perception; (2) Rhythm perception evokes both external and internal guidance of somatotopic representations; (3) A link from the limbic system to the internal guidance pathway mediates the "dance habit"; (4) The vestibular reward mechanism is innate. The new synthesis provides an explanation for a number of phenomena not often considered by rhythm researchers. We discuss these along with possible computational implementations and alternative models and propose a number of new directions for future research. PMID:26379522

  8. The sensory-motor theory of rhythm and beat induction 20 years on: a new synthesis and future perspectives

    PubMed Central

    Todd, Neil P. M.; Lee, Christopher S.

    2015-01-01

    Some 20 years ago Todd and colleagues proposed that rhythm perception is mediated by the conjunction of a sensory representation of the auditory input and a motor representation of the body (Todd, 1994a, 1995), and that a sense of motion from sound is mediated by the vestibular system (Todd, 1992a, 1993b). These ideas were developed into a sensory-motor theory of rhythm and beat induction (Todd et al., 1999). A neurological substrate was proposed which might form the biological basis of the theory (Todd et al., 2002). The theory was implemented as a computational model and a number of experiments conducted to test it. In the following time there have been several key developments. One is the demonstration that the vestibular system is primal to rhythm perception, and in related work several experiments have provided further evidence that rhythm perception is body dependent. Another is independent advances in imaging, which have revealed the brain areas associated with both vestibular processing and rhythm perception. A third is the finding that vestibular receptors contribute to auditory evoked potentials (Todd et al., 2014a,b). These behavioral and neurobiological developments demand a theoretical overview which could provide a new synthesis over the domain of rhythm perception. In this paper we suggest four propositions as the basis for such a synthesis. (1) Rhythm perception is a form of vestibular perception; (2) Rhythm perception evokes both external and internal guidance of somatotopic representations; (3) A link from the limbic system to the internal guidance pathway mediates the “dance habit”; (4) The vestibular reward mechanism is innate. The new synthesis provides an explanation for a number of phenomena not often considered by rhythm researchers. We discuss these along with possible computational implementations and alternative models and propose a number of new directions for future research. PMID:26379522

  9. Induction of Long-term Depression-like Plasticity by Pairings of Motor Imagination and Peripheral Electrical Stimulation

    PubMed Central

    Jochumsen, Mads; Signal, Nada; Nedergaard, Rasmus W.; Taylor, Denise; Haavik, Heidi; Niazi, Imran K.

    2015-01-01

    Long-term depression (LTD) and long-term potentiation (LTP)-like plasticity are models of synaptic plasticity which have been associated with memory and learning. The induction of LTD and LTP-like plasticity, using different stimulation protocols, has been proposed as a means of addressing abnormalities in cortical excitability associated with conditions such as focal hand dystonia and stroke. The aim of this study was to investigate whether the excitability of the cortical projections to the tibialis anterior (TA) muscle could be decreased when dorsiflexion of the ankle joint was imagined and paired with peripheral electrical stimulation (ES) of the nerve supplying the antagonist soleus muscle. The effect of stimulus timing was evaluated by comparing paired stimulation timed to reach the cortex before, at and after the onset of imagined movement. Fourteen healthy subjects participated in six experimental sessions held on non-consecutive days. The timing of stimulation delivery was determined offline based on the contingent negative variation (CNV) of electroencephalography brain data obtained during imagined dorsiflexion. Afferent stimulation was provided via a single pulse ES to the peripheral nerve paired, based on the CNV, with motor imagination of ankle dorsiflexion. A significant decrease (P = 0.001) in the excitability of the cortical projection of TA was observed when the afferent volley from the ES of the tibial nerve (TN) reached the cortex at the onset of motor imagination based on the CNV. When TN stimulation was delivered before (P = 0.62), or after (P = 0.23) imagined movement onset there was no significant effect. Nor was a significant effect found when ES of the TN was applied independent of imagined movement (P = 0.45). Therefore, the excitability of the cortical projection to a muscle can be inhibited when ES of the nerve supplying the antagonist muscle is precisely paired with the onset of imagined movement. PMID:26648859

  10. Application of Elements of Numerical Methods in the Analysis of Journal Bearings in AC Induction Motors: An Industry Case Study

    ERIC Educational Resources Information Center

    Ahrens, Fred; Mistry, Rajendra

    2005-01-01

    In product engineering there often arise design analysis problems for which a commercial software package is either unavailable or cost prohibitive. Further, these calculations often require successive iterations that can be time intensive when performed by hand, thus development of a software application is indicated. This case relates to the…

  11. Nonlinear Control of the Doubly Fed Induction Motor with Copper Losses Minimization for Electrical Vehicle

    NASA Astrophysics Data System (ADS)

    Drid, S.; Nait-Said, M.-S.; Tadjine, M.; Makouf, A.

    2008-06-01

    There is an increasing interest in electric vehicles due to environmental concerns. Recent efforts are directed toward developing an improved propulsion system for electric vehicles applications with minimal power losses. This paper deals with the high efficient vector control for the reduction of copper losses of the doubly fed motor. Firstly, the feedback linearization control based on Lyapunov approach is employed to design the underlying controller achieving the double fluxes orientation. The fluxes controllers are designed independently of the speed. The speed controller is designed using the Lyapunov method especially employed to the unknown load torques. The global asymptotic stability of the overall system is theoretically proven. Secondly, a new Torque Copper Losses Factor is proposed to deal with the problem of the machine copper losses. Its main function is to optimize the torque in keeping the machine saturation at an acceptable level. This leads to a reduction in machine currents and therefore their accompanied copper losses guaranteeing improved machine efficiency. The simulation results in comparative presentation confirm largely the effectiveness of the proposed DFIM control with a very interesting energy saving contribution.

  12. Transient tracking of low and high-order eccentricity-related components in induction motors via TFD tools

    NASA Astrophysics Data System (ADS)

    Climente-Alarcon, V.; Antonino-Daviu, J.; Riera-Guasp, M.; Pons-Llinares, J.; Roger-Folch, J.; Jover-Rodriguez, P.; Arkkio, A.

    2011-02-01

    The present work is focused on the diagnosis of mixed eccentricity faults in induction motors via the study of currents demanded by the machine. Unlike traditional methods, based on the analysis of stationary currents (Motor Current Signature Analysis (MCSA)), this work provides new findings regarding the diagnosis approach proposed by the authors in recent years, which is mainly focused on the fault diagnosis based on the analysis of transient quantities, such as startup or plug stopping currents (Transient Motor Current Signature Analysis (TMCSA)), using suitable time-frequency decomposition (TFD) tools. The main novelty of this work is to prove the usefulness of tracking the transient evolution of high-order eccentricity-related harmonics in order to diagnose the condition of the machine, complementing the information obtained with the low-order components, whose transient evolution was well characterised in previous works. Tracking of high-order eccentricity-related harmonics during the transient, through their associated patterns in the time-frequency plane, may significantly increase the reliability of the diagnosis, since the set of fault-related patterns arising after application of the corresponding TFD tool is very unlikely to be caused by other faults or phenomena. Although there are different TFD tools which could be suitable for the transient extraction of these harmonics, this paper makes use of a Wigner-Ville distribution (WVD)-based algorithm in order to carry out the time-frequency decomposition of the startup current signal, since this is a tool showing an excellent trade-off between frequency resolution at both high and low frequencies. Several simulation results obtained with a finite element-based model and experimental results show the validity of this fault diagnosis approach under several faulty and operating conditions. Also, additional signals corresponding to the coexistence of the eccentricity and other non-fault related phenomena making

  13. Effects of low-intensity AC and/or DC electromagnetic fields on cell attachment and induction of apoptosis

    SciTech Connect

    Blumenthal, N.C.; Ricci, J.; Breger, L.; Zychlinsky, A.; Solomon, H.; Chen, G.G.; Kuznetsov, D.; Dorfman, R.

    1997-05-01

    Rat tendon fibroblast (RTF) and rat bone marrow (RBM) osteoprogenitor cells were cultured and exposed to AC and/or DC magnetic fields in a triaxial Helmholtz coil in an incubator for up to 13 days. The AC fields were at 60 and 1,000 Hz and up to 0.25 mT peak to peak, and the DC fields were up to 0.25 mT. At various combinations of field strengths and frequencies, AC and/or DC fields resulted in extensive detachment of preattached cells and prevented the normal attachment of cells not previously attached to substrates. In addition, the fields resulted in altered cell morphologies. When RTF and RBM cells were removed from the fields after several days of exposure, they partially reattached and assumed more normal morphologies. An additional set of experiments described in the Appendix corroborates these findings and also shows that low-frequency EMF also initiates apoptosis, i.e., programmed cell death, at the onset of cell detachment. Taken together, these results suggest that the electromagnetic fields result in significant alterations in cell metabolism and cytoskeleton structure. Further work is required to determine the relative effect of the electric and magnetic fields on these phenomena. The research has implications for understanding the role of fields in affecting bone healing in fracture nonunions, in cell detachment in cancer metastasis, and in the effect of EMF on organisms generally.

  14. Effect analysis of magnet on L[sub d] and L[sub q] inductance of permanent magnet assisted synchronous reluctance motor using finite element method

    SciTech Connect

    Lee, J.H.; Kim, J.C.; Hyun, D.S. . Dept. of Electrical Engineering)

    1999-05-01

    This study investigates the characteristics of Permanent Magnet Assisted Synchronous Reluctance Motor (PMASynRM) using coupled FEM and Preisach modelling. The focus of this paper is the characteristics analysis of d, q axis inductance according to magnetizing direction and quantity of interior permanent magnet for PMASynRM. Investigation on nonlinear characteristic of machine is performed by Preisach's theory application. Comparisons are given with characteristics of normal Synchronous reluctance motor (SynRM) and those according to the quantity of residual flux density (0.3T and 0.4T) in PMASynRM, respectively.

  15. Hysteretic Dependence of Magnetic Flux Density on Primary AC Current in Flat-Type Inductive Fault Current Limiter with YBCO Thin Film Discs

    NASA Astrophysics Data System (ADS)

    Harada, Masayuki; Yokomizu, Yasunobu; Matsumura, Toshiro

    2014-05-01

    This paper focuses on a flat-type inductive superconducting FCL (FIS-FCL) consisting of a pancake coil and a YBCO thin layer disc. AC current injection experiments and magnetic field analysis were carried out for two kinds of FIS-FCL, single-disc model and double-discs model. In the former, the pancake coil was putted on the YBCO disc. In the latter, the pancake coil was sandwiched with two YBCO discs. The double-discs model cancels out the magnetic flux density more effectively than the single-disc model. In the double-discs model, the superconducting state period is longer than in the single-disc model. Thus, it may be concluded that the double-discs model is considered to be suitable for FIS-FCL.

  16. A self-organizing and self-tuning fuzzy logic controller for field oriented control of induction motor drives

    SciTech Connect

    Ashrafzadeh, F.; Nowicki, E.P.; Salmon, J.C.

    1995-12-31

    This paper proposes a design approach for a self-organizing self-tuning fuzzy logic controller, and is applied to the design of a field oriented drive system. The basic structure of a fuzzy logic controller is outlined and the design problems associated with the conventional trial-and-error schemes are addressed. The suitability of the genetic algorithm optimization technique as a means to determine and optimize the fuzzy logic controller design is discussed. In the proposed approach normalization factors and/or membership function parameters and/or the controller policy, are translated into bit-strings. These bit-strings are processed by the genetic algorithm and if the selection process as well as the objective function are chosen properly, a near-optimal solution can be found. To examine the efficiency of the proposed approach, a self-tuning and self-organizing fuzzy logic controller for an indirect field oriented induction motor drive is designed in both a sequential and a concurrent manner. A particular objective function (i.e., a performance index) is chosen to achieve a high dynamic performance. The simulation results demonstrate a significant enhancement in shortening the development time, and improving system performance over a manually tuned fuzzy logic controller.

  17. An Adaptive Supervisory Sliding Fuzzy Cerebellar Model Articulation Controller for Sensorless Vector-Controlled Induction Motor Drive Systems

    PubMed Central

    Wang, Shun-Yuan; Tseng, Chwan-Lu; Lin, Shou-Chuang; Chiu, Chun-Jung; Chou, Jen-Hsiang

    2015-01-01

    This paper presents the implementation of an adaptive supervisory sliding fuzzy cerebellar model articulation controller (FCMAC) in the speed sensorless vector control of an induction motor (IM) drive system. The proposed adaptive supervisory sliding FCMAC comprised a supervisory controller, integral sliding surface, and an adaptive FCMAC. The integral sliding surface was employed to eliminate steady-state errors and enhance the responsiveness of the system. The adaptive FCMAC incorporated an FCMAC with a compensating controller to perform a desired control action. The proposed controller was derived using the Lyapunov approach, which guarantees learning-error convergence. The implementation of three intelligent control schemes—the adaptive supervisory sliding FCMAC, adaptive sliding FCMAC, and adaptive sliding CMAC—were experimentally investigated under various conditions in a realistic sensorless vector-controlled IM drive system. The root mean square error (RMSE) was used as a performance index to evaluate the experimental results of each control scheme. The analysis results indicated that the proposed adaptive supervisory sliding FCMAC substantially improved the system performance compared with the other control schemes. PMID:25815450

  18. Performance improvement of direct torque control system for induction motor in low-speed operation using wavelet network

    NASA Astrophysics Data System (ADS)

    Liu, Hua; Liao, Wei; Wang, Yuguo; Shen, Songhua

    2006-11-01

    To improve the low-speed dynamic performance of induction motor in direct torque control (DTC), a novel method of stator resistance identification based on wavelet network (WN) is presented and the determination of wavelet network structure is discussed. The inputs of the WN are the current error and the change in the current error and the output of the WN is the stator resistance error. The improved least squares algorithm (LSA) is used to fulfill the network structure and parameter identification. By the use of wavelet transform that accurately localizes the characteristics of a signal both in the time and frequency domains, the occurring instants of the stator resistance change can be identified by the multi-scale representation of the signal. Once the instants are detected, the accurate stator flux vector and electromagnetic torque are acquired by the parameter estimator, which makes the DTC applicable in the low region, optimizing the inverter control strategy. By detailed comparison between the wavelet and the typical backward-propagation (BP) neural network, the simulation results show that the proposed method can efficiently reduce the torque ripple and current ripple, superior to the BP neural network.

  19. Hybrid-secondary uncluttered induction machine

    DOEpatents

    Hsu, John S.

    2001-01-01

    An uncluttered secondary induction machine (100) includes an uncluttered rotating transformer (66) which is mounted on the same shaft as the rotor (73) of the induction machine. Current in the rotor (73) is electrically connected to current in the rotor winding (67) of the transformer, which is not electrically connected to, but is magnetically coupled to, a stator secondary winding (40). The stator secondary winding (40) is alternately connected to an effective resistance (41), an AC source inverter (42) or a magnetic switch (43) to provide a cost effective slip-energy-controlled, adjustable speed, induction motor that operates over a wide speed range from below synchronous speed to above synchronous speed based on the AC line frequency fed to the stator.

  20. ELECTRICAL AND ELECTRONIC INDUSTRIAL CONTROL. A-C CONVENTIONAL MAGNETIC MOTOR CONTROL, PART I, UNIT 5, ASSIGNMENTS.

    ERIC Educational Resources Information Center

    SUTTON, MACK C.

    THIS GUIDE IS FOR INDIVIDUAL STUDENT USE IN STUDYING ALTERNATING CURRENT CONVENTIONAL MAGNETIC MOTOR CONTROL IN ELECTRICAL-ELECTRONIC PROGRAMS. IT WAS DEVELOPED BY AN INSTRUCTIONAL MATERIALS SPECIALIST AND ADVISERS. EACH OF THE 10 ASSIGNMENT SHEETS PROVIDES THE LESSON SUBJECT, PURPOSE, INTRODUCTORY INFORMATION, STUDY REFERENCES, SUPPLEMENTARY…

  1. ELECTRICAL AND ELECTRONIC INDUSTRIAL CONTROL. A-C CONVENTIONAL MAGNETIC MOTOR CONTROL, PART I, UNIT 5, INSTRUCTOR'S GUIDE.

    ERIC Educational Resources Information Center

    SUTTON, MACK C.

    THIS GUIDE IS FOR TEACHER USE IN DIRECTING INDIVIDUAL STUDY OF ALTERNATING CURRENT CONVENTIONAL MAGNETIC MOTOR CONTROL IN ELECTRICAL-ELECTRONIC PROGRAMS. IT WAS DEVELOPED BY AN INSTRUCTIONAL MATERIALS SPECIALIST AND ADVISERS. EACH OF THE 10 INSTRUCTOR'S SHEETS GIVES THE LESSON SUBJECT, PURPOSE, INTRODUCTORY INFORMATION, REFERENCES, AND…

  2. ELECTRICAL AND ELECTRONIC INDUSTRIAL CONTROL. A-C CONVENTIONAL MAGNETIC MOTOR CONTROL, PART II, UNIT 6, INSTRUCTOR'S GUIDE.

    ERIC Educational Resources Information Center

    SUTTON, MACK C.

    THIS GUIDE IS FOR TEACHER USE IN DIRECTING INDIVIDUAL STUDY OF ALTERNATING CURRENT CONVENTIONAL MAGNETIC MOTOR CONTROL IN ELECTRICAL-ELECTRONIC PROGRAMS. IT WAS DEVELOPED BY AN INSTRUCTIONAL MATERIALS SPECIALIST AND ADVISERS. EACH OF THE 10 INSTRUCTOR'S SHEETS GIVES THE LESSON SUBJECT, PURPOSE, INTRODUCTORY INFORMATION, REFERENCES, SUPPLEMENTARY…

  3. ELECTRICAL AND ELECTRONIC INDUSTRIAL CONTROL. A-C CONVENTIONAL MAGNETIC MOTOR CONTROL, PART II, UNIT 6, ASSIGNMENTS.

    ERIC Educational Resources Information Center

    SUTTON, MACK C.

    THIS STUDY GUIDE IS FOR INDIVIDUAL STUDENT USE IN STUDYING ALTERNATING CURRENT CONVENTIONAL MAGNETIC MOTOR CONTROL IN ELECTRICAL-ELECTRONIC PROGRAMS. IT WAS DEVELOPED BY AN INSTRUCTIONAL MATERIALS SPECIALIST AND ADVISERS. EACH OF THE 10 ASSIGNMENT SHEETS PROVIDES THE LESSON SUBJECT, PURPOSE, INTRODUCTORY INFORMATION, STUDY REFERENCES,…

  4. A PWM transistor inverter for an ac electric vehicle drive

    NASA Technical Reports Server (NTRS)

    Slicker, J. M.

    1981-01-01

    A prototype system consisting of closely integrated motor, inverter, and transaxle has been built in order to demonstrate the feasibility of a three-phase ac transistorized inverter for electric vehicle applications. The microprocessor-controlled inverter employs monolithic power transistors to drive an oil-cooled, three-phase induction traction motor at a peak output power of 30 kW from a 144 V battery pack. Transistor safe switching requirements are discussed, and a circuit is presented for recovering trapped snubber inductor energy at transistor turn-off.

  5. Induction motor analysis

    NASA Technical Reports Server (NTRS)

    Bollenbacher, G.

    1977-01-01

    FORTRAN program calculates torque speed characteristics, electrical characteristics, magnetic flux densities, and weight plus other parameters. Input to program consists of physical dimensions, winding temperatures, winding description, material characteristics, and electrical design parameters.

  6. Sub-Doppler Spectra of Infrared Hyperfine Transitions of Nitric Oxide Using a Pulse Modulated Quantum Cascade Laser: Rapid Passage, Free Induction Decay and the AC Stark Effect

    SciTech Connect

    Duxbury, Geoffrey; Kelly, James F.; Blake, Thomas A.; Langford, Nigel

    2012-05-07

    Using a low power, rapid (nsec) pulse-modulated quantum cascade (QC) laser, collective coherent effects in the 5 {micro}m spectrum of nitric oxide have been demonstrated by the observation of sub-Doppler hyperfine splitting and also Autler-Townes splitting of Doppler broadened lines. For nitrous oxide, experiments and model calculations have demonstrated that two main effects occur with ulsemodulated (chirped) quantum cascade lasers: free induction decay signals, and signals induced by rapid passage during the laser chirp. In the open shell molecule, NO, in which both {Lambda}-doubling splitting and hyperfine structure occur, laser field-induced coupling between the hyperfine levels of the two {Lambda}-doublet components can induce a large AC Stark effect. This may be observed as sub-Doppler structure, field-induced splittings, or Autler-Townes splitting of a Doppler broadened line. These represent an extension of the types of behaviour observed in the closed shell molecule nitrous oxide, using the same apparatus, when probed with an 8 {micro}m QC laser.

  7. Flywheel Size Design Considerations and Experimental Verification Using a 50-kW System for Voltage Sag Compensator with Flywheel Induction Motor

    NASA Astrophysics Data System (ADS)

    Kato, Shuhei; Cheng, Miao-Miao; Sumitani, Hideo; Shimada, Ryuichi

    Flywheel energy storage systems can be used as uninterrupted power supply system because they are environmentally friendly and have high durability. The use of a simple voltage sag compensator with a low-speed heavy flywheel and a low-cost squirrel-cage induction motor/generator is proposed. First, the ability of the proposed system to maintain the load voltage at 100% when the grid is under voltage sag is experimentally-validated. Next, design guides of the flywheel stored energy are discussed. Experimental verification of a 50-kW class system are carried out, and the results show good agreement with the developed design guides.

  8. A 2D magnetic and 3D mechanical coupled finite element model for the study of the dynamic vibrations in the stator of induction motors

    NASA Astrophysics Data System (ADS)

    Martinez, J.; Belahcen, A.; Detoni, J. G.

    2016-01-01

    This paper presents a coupled Finite Element Model in order to study the vibrations in induction motors under steady-state. The model utilizes a weak coupling strategy between both magnetic and elastodynamic fields on the structure. Firstly, the problem solves the magnetic vector potential in an axial cut and secondly the former solution is coupled to a three dimensional model of the stator. The coupling is performed using projection based algorithms between the computed magnetic solution and the three-dimensional mesh. The three-dimensional model of the stator includes both end-windings and end-shields in order to give a realistic picture of the motor. The present model is validated using two steps. Firstly, a modal analysis hammer test is used to validate the material characteristic of this complex structure and secondly an array of accelerometer sensors is used in order to study the rotating waves using multi-dimensional spectral techniques. The analysis of the radial vibrations presented in this paper firstly concludes that slot harmonic components are visible when the motor is loaded. Secondly, the multidimensional spectrum presents the most relevant mechanical waves on the stator such as the ones produced by the space harmonics or the saturation of the iron core. The direct retrieval of the wave-number in a multi-dimensional spectrum is able to show the internal current distribution in a non-intrusive way. Experimental results for healthy induction motors are showing mechanical imbalances in a multi-dimensional spectrum in a more straightforward form.

  9. Comparison of AC drives for electric vehicles -- A report on experts` opinion survey

    SciTech Connect

    Chang, L.

    1994-08-01

    It is recognized that wide applications of electric vehicles (EVs) will bring tremendous social, economical and ecological benefits. With the growing interests in electric vehicles, much effort is demanded for the development of efficient, reliable and economical AC drives` for EV propulsion purpose. Both induction motor (IM) drives and permanent magnet brushless DC motor (BDCM) drives have been applied to EVs. Switched reluctance motor (SRM) drives have been proposed as an alternative for EV propulsion. In order to assess the suitability of IM, BDCM and SRM drives for EV applications and to provide a technical support for the development and selection of future EV propulsion systems, the existing EV AC propulsion drives were compared, and a survey of experts` opinions was conducted. Comparison of the three AC drives was made on a relative and a quantitative basis using the survey questionnaires. According to the majority of the experts, induction motor drives are best suited for EV propulsion purpose, due to their low cost, high reliability, high speed, established converter and manufacturing technology, low torque ripple/noise and absence of position sensors. BDCM drives feature compactness, low weight and high efficiency and therefore provide an alternative for EV propulsion. The experts regard insulated gate bipolar transistors (IGBTs) as the most suited power semiconductor devices for AC drive converters at the present stage. 7 refs.

  10. Reactor coolant pump testing using motor current signatures analysis

    SciTech Connect

    Burstein, N.; Bellamy, J.

    1996-12-01

    This paper describes reactor coolant pump motor testing carried out at Florida Power Corporation`s Crystal River plant using Framatome Technologies` new EMPATH (Electric Motor Performance Analysis and Trending Hardware) system. EMPATH{trademark} uses an improved form of Motor Current Signature Analysis (MCSA), technology, originally developed at Oak Ridge National Laboratories, for detecting deterioration in the rotors of AC induction motors. Motor Current Signature Analysis (MCSA) is a monitoring tool for motor driven equipment that provides a non-intrusive means for detecting the presence of mechanical and electrical abnormalities in the motor and the driven equipment. The base technology was developed at the Oak Ridge National Laboratory as a means for determining the affects of aging and service wear specifically on motor-operated valves used in nuclear power plant safety systems, but it is applicable to a broad range of electric machinery. MCSA is based on the recognition that an electric motor (ac or dc) driving a mechanical load acts as an efficient and permanently available transducer by sensing mechanical load variations, large and small, long-term and rapid, and converting them into variations in the induced current generated in the motor windings. The motor current variations, resulting from changes in load caused by gears, pulleys, friction, bearings, and other conditions that may change over the life of the motor, are carried by the electrical cables powering the motor and are extracted at any convenient location along the motor lead. These variations modulate the 60 Hz carrier frequency and appear as sidebands in the spectral plot.

  11. Development of a computer algorithm for the analysis of variable-frequency AC drives: Case studies included

    NASA Technical Reports Server (NTRS)

    Kankam, M. David; Benjamin, Owen

    1991-01-01

    The development of computer software for performance prediction and analysis of voltage-fed, variable-frequency AC drives for space power applications is discussed. The AC drives discussed include the pulse width modulated inverter (PWMI), a six-step inverter and the pulse density modulated inverter (PDMI), each individually connected to a wound-rotor induction motor. Various d-q transformation models of the induction motor are incorporated for user-selection of the most applicable model for the intended purpose. Simulation results of selected AC drives correlate satisfactorily with published results. Future additions to the algorithm are indicated. These improvements should enhance the applicability of the computer program to the design and analysis of space power systems.

  12. Induction voidmeter

    DOEpatents

    Anderson, Thomas T.; Roop, Conard J.; Schmidt, Kenneth J.; Brewer, John

    1986-01-01

    An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge circuit, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; applying an AC excitation signal to said input branch; and detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

  13. Induction voidmeter

    DOEpatents

    Anderson, T.T.; Roop, C.J.; Schmidt, K.J.; Brewer, J.

    1983-12-21

    An induction voidmeter for detecting voids in a conductive fluid may comprise: a four arm bridge circuit having two adjustable circuit elements connected as opposite arms of said bridge, an input branch, and an output branch; two induction coils, bifilarly wound together, connected as the remaining two opposing arms of said bridge circuit and positioned such that the conductive fluid passes through said coils; means for applying an AC excitation signal to said input branch; and means for detecting the output signal generated in response to said excitation signal across said output branch. The induction coils may be located outside or inside a non-magnetic pipe containing the conductive fluid.

  14. PWM-switching pattern-based diagnosis scheme for single and multiple open-switch damages in VSI-fed induction motor drives.

    PubMed

    Trabelsi, Mohamed; Boussak, Mohamed; Gossa, Moncef

    2012-03-01

    This paper deals with a fault detection technique for insulated-gate bipolar transistors (IGBTs) open-circuit faults in voltage source inverter (VSI)-fed induction motor drives. The novelty of this idea consists in analyzing the pulse-width modulation (PWM) switching signals and the line-to-line voltage levels during the switching times, under both healthy and faulty operating conditions. The proposed method requires line-to-line voltage measurement, which provides information about switching states and is not affected by the load. The fault diagnosis scheme is achieved using simple hardware and can be included in the existing inverter system without any difficulty. In addition, it allows not only accurate single and multiple faults diagnosis but also minimization of the fault detection time to a maximum of one switching period (T(c)). Simulated and experimental results on a 3-kW squirrel-cage induction motor drive are displayed to validate the feasibility and the effectiveness of the proposed strategy. PMID:22153956

  15. Induction motors airgap-eccentricity detection through the discrete wavelet transform of the apparent power signal under non-stationary operating conditions.

    PubMed

    Yahia, K; Cardoso, A J M; Ghoggal, A; Zouzou, S E

    2014-03-01

    Fast Fourier transform (FFT) analysis has been successfully used for fault diagnosis in induction machines. However, this method does not always provide good results for the cases of load torque, speed and voltages variation, leading to a variation of the motor-slip and the consequent FFT problems that appear due to the non-stationary nature of the involved signals. In this paper, the discrete wavelet transform (DWT) of the apparent-power signal for the airgap-eccentricity fault detection in three-phase induction motors is presented in order to overcome the above FFT problems. The proposed method is based on the decomposition of the apparent-power signal from which wavelet approximation and detail coefficients are extracted. The energy evaluation of a known bandwidth permits to define a fault severity factor (FSF). Simulation as well as experimental results are provided to illustrate the effectiveness and accuracy of the proposed method presented even for the case of load torque variations. PMID:24461376

  16. Type-1 and Type-2 Fuzzy Logic and Sliding-Mode Based Speed Control of Direct Torque and Flux Control Induction Motor Drives - A Comparative Study

    NASA Astrophysics Data System (ADS)

    Ramesh, Tejavathu; Panda, A. K.; Kumar, S. Shiva

    2013-08-01

    In this research study, the performance of direct torque and flux control induction motor drive (IMD) is presented using five different speed control techniques. The performance of IMD mainly depends on the design of speed controller. The PI speed controller requires precise mathematical model, continuous and appropriate gain values. Therefore, adaptive control based speed controller is desirable to achieve high-performance drive. The sliding-mode speed controller (SMSC) is developed to achieve continuous control of motor speed and torque. Furthermore, the type-1 fuzzy logic speed controller (T1FLSC), type-1 fuzzy SMSC and a new type-2 fuzzy logic speed controller are designed to obtain high performance, dynamic tracking behaviour, speed accuracy and also robustness to parameter variations. The performance of each control technique has been tested for its robustness to parameter uncertainties and load disturbances. The detailed comparison of different control schemes are carried out in a MATALB/Simulink environment at different speed operating conditions, such as, forward and reversal motoring under no-load, load and sudden change in speed.

  17. Detection of air-gap eccentricity and broken-rotor bar conditions in a squirrel-cage induction motor using the radial flux sensor

    SciTech Connect

    Hwang, Don-Ha; Woo, Byung-Chul; Sun, Jong-Ho; Kang, Dong-Sik; Han, Sang-Bo; Kim, Byung-Kuk; Cho, Youn-Hyun

    2008-04-01

    A new method for detecting eccentricity and broken rotor bar conditions in a squirrel-cage induction motor is proposed. Air-gap flux variation analysis is done using search coils, which are inserted at stator slots. Using this method, the leakage flux in radial direction can be directly detected. Using finite element method, the air-gap flux variation is accurately modeled and analyzed. From the results of the simulation, a motor under normal condition shows maximum magnetic flux density of 1.3 T. On the other hand, the eccentric air-gap condition displays about 1.1 T at 60 deg. and 1.6 T at 240 deg. A difference of flux density is 0.5 T in the abnormal condition, whereas no difference is detected in the normal motor. In the broken rotor bar conditions, the flux densities at 65 deg. and 155 deg. are about 0.4 T and 0.8 T, respectively. These simulation results are coincided with those of experiment. Consequently, the measurement of the magnetic flux at air gap is one of effective ways to discriminate the faulted conditions of the eccentricity and broken rotor bars.

  18. Detection of air-gap eccentricity and broken-rotor bar conditions in a squirrel-cage induction motor using the radial flux sensor

    NASA Astrophysics Data System (ADS)

    Hwang, Don-Ha; Han, Sang-Bo; Woo, Byung-Chul; Sun, Jong-Ho; Kang, Dong-Sik; Kim, Byung-Kuk; Cho, Youn-Hyun

    2008-04-01

    A new method for detecting eccentricity and broken rotor bar conditions in a squirrel-cage induction motor is proposed. Air-gap flux variation analysis is done using search coils, which are inserted at stator slots. Using this method, the leakage flux in radial direction can be directly detected. Using finite element method, the air-gap flux variation is accurately modeled and analyzed. From the results of the simulation, a motor under normal condition shows maximum magnetic flux density of 1.3T. On the other hand, the eccentric air-gap condition displays about 1.1T at 60° and 1.6T at 240°. A difference of flux density is 0.5T in the abnormal condition, whereas no difference is detected in the normal motor. In the broken rotor bar conditions, the flux densities at 65° and 155° are about 0.4 T and 0.8T, respectively. These simulation results are coincided with those of experiment. Consequently, the measurement of the magnetic flux at air gap is one of effective ways to discriminate the faulted conditions of the eccentricity and broken rotor bars.

  19. An Efficient Power Regeneration and Drive Method of an Induction Motor by Means of an Optimal Torque Derived by Variational Method

    NASA Astrophysics Data System (ADS)

    Inoue, Kaoru; Ogata, Kenji; Kato, Toshiji

    When the motor speed is reduced by using a regenerative brake, the mechanical energy of rotation is converted to the electrical energy. When the regenerative torque is large, the corresponding current increases so that the copper loss also becomes large. On the other hand, the damping effect of rotation increases according to the time elapse when the regenerative torque is small. In order to use the limited energy effectively, an optimal regenerative torque should be discussed in order to regenerate electrical energy as much as possible. This paper proposes a design methodology of a regenerative torque for an induction motor to maximize the regenerative electric energy by means of the variational method. Similarly, an optimal torque for acceleration is derived in order to minimize the energy to drive. Finally, an efficient motor drive system with the proposed optimal torque and the power storage system stabilizing the DC link voltage will be proposed. The effectiveness of the proposed methods are illustrated by both simulations and experiments.

  20. Motor Controllers

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Kollmorgen Corporation's Mermaid II two person submersible is propeller-driven by a system of five DC brushless motors with new electronic controllers that originated in work performed in a NASA/DOE project managed by Lewis Research Center. A key feature of the system is electric commutation rather than mechanical commutation for converting AC current to DC.

  1. High-vibration detection using motor current signature analysis

    SciTech Connect

    Castleberry, K.N.

    1996-08-01

    Motor current signature analysis (CSA) has been used for several years as a diagnostic tool for electrical problems in ac, induction motors. Personnel at Oak Ridge National Laboratory have found that CSA can also provide information about system vibrations and imbalances similar to the information provided by an accelerometer. As a result, CSA techniques for monitoring the status of the equipment, such as pumps and compressors, driven by induction motors have been developed and used in dedicated monitoring systems. In this work, researchers have found that CSA responds proportionately to imbalances in rotating equipment and can be used to detect the In high-vibration conditions that can result. This report describes how vibration monitoring with CSA can be implemented and presents test data to support that use.

  2. Novel rotor position estimation technique for switched reluctance motor (SRM)

    NASA Astrophysics Data System (ADS)

    Moradi, Hassan; Afjei, Ebrahim

    2011-09-01

    This article presents a new and novel method which is designed to detect the rotor position at standstill and at low speeds in switched reluctance motor. Since the inductance parameter plays a significant role both in the steady state and in the dynamic characteristics of an electromagnetic device, the rotor position can be determined using inductance bridge systems to measure unknown inductance and resistance values. In this method we use motor winding in Maxwell-Wien Bridge, with the standard capacitor and the resistor in parallel with it adjusted to achieve balance in an aligned position when the maximum inductance occurs. The supply voltage, in conjunction with the drive transistor, produces short pulses for this AC bridge. The condition of the balanced bridge v 0 = 0 leads to the relation between the impedances of the bridge branches. The phase inductance varies with the rotor position. Therefore the motor goes into an unaligned position and the Maxwell-Wien Bridge goes into an unbalanced condition thus causing variation in the state of the bridge output. It then continues to sense the rotor position with the motor running by applying the same procedure, but only to the un-energised phases winding. The simulation and experimentally obtained results demonstrate the feasibility and practicability of this method.

  3. Simulative and experimental investigation on stator winding turn and unbalanced supply voltage fault diagnosis in induction motors using Artificial Neural Networks.

    PubMed

    Lashkari, Negin; Poshtan, Javad; Azgomi, Hamid Fekri

    2015-11-01

    The three-phase shift between line current and phase voltage of induction motors can be used as an efficient fault indicator to detect and locate inter-turn stator short-circuit (ITSC) fault. However, unbalanced supply voltage is one of the contributing factors that inevitably affect stator currents and therefore the three-phase shift. Thus, it is necessary to propose a method that is able to identify whether the unbalance of three currents is caused by ITSC or supply voltage fault. This paper presents a feedforward multilayer-perceptron Neural Network (NN) trained by back propagation, based on monitoring negative sequence voltage and the three-phase shift. The data which are required for training and test NN are generated using simulated model of stator. The experimental results are presented to verify the superior accuracy of the proposed method. PMID:26412499

  4. Control algorithm for the inverter fed induction motor drive with DC current feedback loop based on principles of the vector control

    SciTech Connect

    Vuckovic, V.; Vukosavic, S. )

    1992-01-01

    This paper brings out a control algorithm for VSI fed induction motor drives based on the converter DC link current feedback. It is shown that the speed and flux can be controlled over the wide speed and load range quite satisfactorily for simpler drives. The base commands of both the inverter voltage and frequency are proportional to the reference speed, but each of them is further modified by the signals derived from the DC current sensor. The algorithm is based on the equations well known from the vector control theory, and is aimed to obtain the constant rotor flux and proportionality between the electrical torque, the slip frequency and the active component of the stator current. In this way, the problems of slip compensation, Ri compensation and correction of U/f characteristics are solved in the same time. Analytical considerations and computer simulations of the proposed control structure are in close agreement with the experimental results measured on a prototype drive.

  5. Performance Improvement of Induction Motor Speed Sensor-Less Vector Control System Using an Adaptive Observer with an Estimated Flux Feedback in Low Speed Range

    NASA Astrophysics Data System (ADS)

    Fukumoto, Tetsuya; Kato, Yousuke; Kurita, Kazuya; Hayashi, Yoichi

    Because of various errors caused by dead time, temperature variation of resistance and so on, the speed estimation error is inevitable in the speed sensor-less vector control methods of the induction motor. Especially, the speed control loop becomes unstable at near zero frequency. In order to solve these problems, this paper proposes a novel design of an adaptive observer for the speed estimation. Adding a feedback loop of the error between the estimated and reference fluxes, the sensitivity of the current error signals for the speed estimation and the primary resistance identification are improved. The proposed system is analyzed and the appropriate feedback gains are derived. The experimental results showed good performance in low speed range.

  6. An AC drive system for a battery driven moped

    SciTech Connect

    Nandi, S.; Saha, S.; Sharon, M.; Sundersingh, V.P.

    1995-12-31

    A petrol driven moped is converted to an electric one by replacing the petrol engine by a three phase 1.5 HR, AC squirrel cage induction motor drive system. The motor voltage rating selected is 200 V to keep the DC boost voltage level to a reasonable value.f the power source used is a high energy density, 24 V, 110 Ah, Ni-Zn battery. A modified indirect current controlled step-up chopper as well as a standard push-pull DC-DC boost converter is studied for the boost scheme. A simple three phase quasi-square wave inverter is designed along with suitable protection for driving the motor. Successful trial test of the system has been conducted at the laboratory.

  7. ac powertrain for an electric vehicle. Phase 2 and Phase 3 final report

    SciTech Connect

    Slicker, J.M.

    1984-11-01

    This report describes work relating to Phases 2 and 3 development and testing of an ac powertrain for a 25 hp four-passenger electric vehicle. The system, which consists of a two-speed automatic mechanical transaxle, 18.6 kW ac induction traction motor, 33.6 kW inverter and overall logic controller, was installed and evaluated in a converted Mercury Lynx rolling test bed vehicle. An on-board charger and an auxiliary dc-to-dc converter were integrated into the inverter/controller package.

  8. Study of the generator/motor operation of induction machines in a high frequency link space power system

    NASA Technical Reports Server (NTRS)

    Lipo, Thomas A.; Sood, Pradeep K.

    1987-01-01

    Static power conversion systems have traditionally utilized dc current or voltage source links for converting power from one ac or dc form to another since it readily achieves the temporary energy storage required to decouple the input from the output. Such links, however, result in bulky dc capacitors and/or inductors and lead to relatively high losses in the converters due to stresses on the semiconductor switches. The feasibility of utilizing a high frequency sinusoidal voltage link to accomplish the energy storage and decoupling function is examined. In particular, a type of resonant six pulse bridge interface converter is proposed which utilizes zero voltage switching principles to minimize switching losses and uses an easy to implement technique for pulse density modulation to control the amplitude, frequency, and the waveshape of the synthesized low frequency voltage or current. Adaptation of the proposed topology for power conversion to single-phase ac and dc voltage or current outputs is shown to be straight forward. The feasibility of the proposed power circuit and control technique for both active and passive loads are verified by means of simulation and experiment.

  9. Induction of A9 dopaminergic neurons from neural stem cells improves motor function in an animal model of Parkinson's disease.

    PubMed

    O'Keeffe, Fiona E; Scott, Sarah A; Tyers, Pam; O'Keeffe, Gerard W; Dalley, Jeffrey W; Zufferey, Romain; Caldwell, Maeve A

    2008-03-01

    Neural stem cells (NSCs) are widely endorsed as a cell source for replacement strategies in neurodegenerative disease. However, their usefulness is currently limited by the inability to induce specific neurotransmitter phenotypes in these cells. In order to direct dopaminergic neuronal fate, we overexpressed Pitx3 in NSCs that were then exposed to E11 developing ventral mesencephalon (VM) in explant culture. This resulted in a significant potentiation of dopaminergic differentiation of the cells. When transplanted into the 6-hydroxydopamine lesioned Parkinsonian rats, these cografts of VM and Pitx3 overexpressing NSCs resulted in a significant restitution of motor function. In addition, there were greater numbers of Girk2 positive A9 neurons in the periphery of the transplants that were NSC derived. This demonstrates that given the correct signals, NSCs can be induced to become dopaminergic neurons that can differentiate into the correct nigrastriatal phenotype required for the treatment of Parkinson's disease. PMID:18202103

  10. Marked synergism between mutant SOD1 and glutamate transport inhibition in the induction of motor neuronal degeneration in spinal cord slice cultures.

    PubMed

    Yin, Hong Z; Weiss, John H

    2012-04-11

    Loss of astrocytic glutamate transport capacity in ALS spinal cord supports an excitotoxic contribution to motor neuron (MN) damage in the disease, and dominant gain of function mutations in Cu/Zn superoxide dismutase (SOD1) cause certain familial forms of ALS. We have used organotypic slice cultures from wild type and G93A SOD1 mutant rat spinal cords to examine interactions between excitotoxicity and the presence of mutant SOD1 in the induction of MN degeneration. Slice cultures were prepared from 1 week old pups, and after an additional week in vitro, some were exposed to either a low level (30 μM) of the glutamate uptake inhibitor, trans-pyrrolidine-2,4-dicarboxylic acid (PDC) for 3 weeks, or a higher level (50 μM) for 48 h, followed by histochemical labeling to assess MN injury. In wild type animals these exposures caused relatively little MN degeneration. Similarly, little MN degeneration was seen in slices from SOD1 mutant animals that were not exposed to PDC. However, addition of PDC to SOD1 mutant slices resulted in substantial MN injury, which was markedly attenuated by a Ca2+ permeable AMPA-type (Ca-AMPA) glutamate channel blocker, or by a nitric oxide synthase antagonist. These observations illustrate the utility of the organotypic culture model for the investigation of intracellular interactions underlying MN degeneration in ALS, and support the hypothesis that activation of Ca-AMPA channels on MNs provides a metabolic burden that synergizes with deleterious effects of mutant SOD1 in the induction of MN injury. PMID:22370146

  11. AC propulsion system for an electric vehicle, phase 2

    NASA Technical Reports Server (NTRS)

    Slicker, J. M.

    1983-01-01

    A second-generation prototype ac propulsion system for a passenger electric vehicle was designed, fabricated, tested, installed in a modified Mercury Lynx vehicle and track tested at the Contractor's site. The system consisted of a Phase 2, 18.7 kw rated ac induction traction motor, a 192-volt, battery powered, pulse-width-modulated, transistorized inverter packaged for under rear seat installation, a 2-axis, 2-speed, automatically-shifted mechanical transaxle and a microprocessor-based powertrain/vehicle controller. A diagnostics computer to assist tuning and fault finding was fabricated. Dc-to-mechanical-system efficiency varied from 78% to 82% as axle speed/torque ranged from 159 rpm/788 nm to 65 rpm/328 nm. Track test efficiency results suggest that the ac system will be equal or superior to dc systems when driving urban cycles. Additional short-term work is being performed under a third contract phase (AC-3) to raise transaxle efficiency to predicted levels, and to improve starting and shifting characteristics. However, the long-term challenge to the system's viability remains inverter cost. A final report on the Phase 2 system, describing Phase 3 modifications, will be issued at the conclusion of AC-3.

  12. AC propulsion system for an electric vehicle, phase 2

    NASA Astrophysics Data System (ADS)

    Slicker, J. M.

    1983-06-01

    A second-generation prototype ac propulsion system for a passenger electric vehicle was designed, fabricated, tested, installed in a modified Mercury Lynx vehicle and track tested at the Contractor's site. The system consisted of a Phase 2, 18.7 kw rated ac induction traction motor, a 192-volt, battery powered, pulse-width-modulated, transistorized inverter packaged for under rear seat installation, a 2-axis, 2-speed, automatically-shifted mechanical transaxle and a microprocessor-based powertrain/vehicle controller. A diagnostics computer to assist tuning and fault finding was fabricated. Dc-to-mechanical-system efficiency varied from 78% to 82% as axle speed/torque ranged from 159 rpm/788 nm to 65 rpm/328 nm. Track test efficiency results suggest that the ac system will be equal or superior to dc systems when driving urban cycles. Additional short-term work is being performed under a third contract phase (AC-3) to raise transaxle efficiency to predicted levels, and to improve starting and shifting characteristics. However, the long-term challenge to the system's viability remains inverter cost. A final report on the Phase 2 system, describing Phase 3 modifications, will be issued at the conclusion of AC-3.

  13. Vinpocetine Inhibits Streptococcus pneumoniae–Induced Upregulation of Mucin MUC5AC Expression via Induction of MKP-1 Phosphatase in the Pathogenesis of Otitis Media

    PubMed Central

    Lee, Ji-Yun; Komatsu, Kensei; Lee, Byung-Cheol; Miyata, Masanori; O’Neill Bohn, Ashley; Xu, Haidong

    2015-01-01

    Mucin overproduction is a hallmark of otitis media (OM). Streptococcus pneumoniae is one of the most common bacterial pathogens causing OM. Mucin MUC5AC plays an important role in mucociliary clearance of bacterial pathogens. However, if uncontrolled, excessive mucus contributes significantly to conductive hearing loss. Currently, there is a lack of effective therapeutic agents that suppress mucus overproduction. In this study, we show that a currently existing antistroke drug, vinpocetine, a derivative of the alkaloid vincamine, inhibited S. pneumoniae–induced mucin MUC5AC upregulation in cultured middle ear epithelial cells and in the middle ear of mice. Moreover, vinpocetine inhibited MUC5AC upregulation by inhibiting the MAPK ERK pathway in an MKP-1–dependent manner. Importantly, ototopical administration of vinpocetine postinfection inhibited MUC5AC expression and middle ear inflammation induced by S. pneumoniae and reduced hearing loss and pneumococcal loads in a well-established mouse model of OM. Thus, these studies identified vinpocetine as a potential therapeutic agent for inhibiting mucus production in the pathogenesis of OM. PMID:25972475

  14. Vinpocetine inhibits Streptococcus pneumoniae-induced upregulation of mucin MUC5AC expression via induction of MKP-1 phosphatase in the pathogenesis of otitis media.

    PubMed

    Lee, Ji-Yun; Komatsu, Kensei; Lee, Byung-Cheol; Miyata, Masanori; O'Neill Bohn, Ashley; Xu, Haidong; Yan, Chen; Li, Jian-Dong

    2015-06-15

    Mucin overproduction is a hallmark of otitis media (OM). Streptococcus pneumoniae is one of the most common bacterial pathogens causing OM. Mucin MUC5AC plays an important role in mucociliary clearance of bacterial pathogens. However, if uncontrolled, excessive mucus contributes significantly to conductive hearing loss. Currently, there is a lack of effective therapeutic agents that suppress mucus overproduction. In this study, we show that a currently existing antistroke drug, vinpocetine, a derivative of the alkaloid vincamine, inhibited S. pneumoniae-induced mucin MUC5AC upregulation in cultured middle ear epithelial cells and in the middle ear of mice. Moreover, vinpocetine inhibited MUC5AC upregulation by inhibiting the MAPK ERK pathway in an MKP-1-dependent manner. Importantly, ototopical administration of vinpocetine postinfection inhibited MUC5AC expression and middle ear inflammation induced by S. pneumoniae and reduced hearing loss and pneumococcal loads in a well-established mouse model of OM. Thus, these studies identified vinpocetine as a potential therapeutic agent for inhibiting mucus production in the pathogenesis of OM. PMID:25972475

  15. Induction machine

    DOEpatents

    Owen, Whitney H.

    1980-01-01

    A polyphase rotary induction machine for use as a motor or generator utilizing a single rotor assembly having two series connected sets of rotor windings, a first stator winding disposed around the first rotor winding and means for controlling the current induced in one set of the rotor windings compared to the current induced in the other set of the rotor windings. The rotor windings may be wound rotor windings or squirrel cage windings.

  16. Advanced ac powertrain for electric vehicles

    SciTech Connect

    Slicker, J.M.; Kalns, L.

    1985-01-01

    The design of an ac propulsion system for an electric vehicle includes a three-phase induction motor, transistorized PWM inverter/battery charger, microprocessor-based controller, and two-speed automatic transaxle. This system was built and installed in a Mercury Lynx test bed vehicle as part of a Department of Energy propulsion system development program. An integral part of the inverter is a 4-kw battery charger which utilizes one of the bridge transistors. The overall inverter strategy for this configuration is discussed. The function of the microprocessor-based controller is described. Typical test results of the total vehicle and each of its major components are given, including system efficiencies and test track performance results.

  17. Type-2 fuzzy logic control based MRAS speed estimator for speed sensorless direct torque and flux control of an induction motor drive.

    PubMed

    Ramesh, Tejavathu; Kumar Panda, Anup; Shiva Kumar, S

    2015-07-01

    In this research study, a model reference adaptive system (MRAS) speed estimator for speed sensorless direct torque and flux control (DTFC) of an induction motor drive (IMD) using two adaptation mechanism schemes are proposed to replace the conventional proportional integral controller (PIC). The first adaptation mechanism scheme is based on Type-1 fuzzy logic controller (T1FLC), which is used to achieve high performance sensorless drive in both transient as well as steady state conditions. However, the Type-1 fuzzy sets are certain and unable to work effectively when higher degree of uncertainties presents in the system which can be caused by sudden change in speed or different load disturbances, process noise etc. Therefore, a new Type-2 fuzzy logic controller (T2FLC) based adaptation mechanism scheme is proposed to better handle the higher degree of uncertainties and improves the performance and also robust to various load torque and sudden change in speed conditions, respectively. The detailed performances of various adaptation mechanism schemes are carried out in a MATLAB/Simulink environment with a speed sensor and speed sensorless modes of operation when an IMD is operating under different operating conditions, such as, no-load, load and sudden change in speed, respectively. To validate the different control approaches, the system also implemented on real-time system and adequate results are reported for its validation. PMID:25887841

  18. Electromechanical systems with transient high power response operating from a resonant AC link

    NASA Technical Reports Server (NTRS)

    Burrows, Linda M.; Hansen, Irving G.

    1992-01-01

    The combination of an inherently robust asynchronous (induction) electrical machine with the rapid control of energy provided by a high frequency resonant AC link enables the efficient management of higher power levels with greater versatility. This could have a variety of applications from launch vehicles to all-electric automobiles. These types of systems utilize a machine which is operated by independent control of both the voltage and frequency. This is made possible by using an indirect field-oriented control method which allows instantaneous torque control in all four operating quadrants. Incorporating the AC link allows the converter in these systems to switch at the zero crossing of every half cycle of the AC waveform. This zero loss switching of the link allows rapid energy variations to be achieved without the usual frequency proportional switching loss. Several field-oriented control systems were developed by LeRC and General Dynamics Space Systems Division under contract to NASA. A description of a single motor, electromechanical actuation system is presented. Then, focus is on a conceptual design for an AC electric vehicle. This design incorporates an induction motor/generator together with a flywheel for peak energy storage. System operation and implications along with the associated circuitry are addressed. Such a system would greatly improve all-electric vehicle ranges over the Federal Urban Driving Cycle (FUD).

  19. Speed control for synchronous motors

    NASA Technical Reports Server (NTRS)

    Packard, H.; Schott, J.

    1981-01-01

    Feedback circuit controls fluctuations in speed of synchronous ac motor. Voltage proportional to phase angle is developed by phase detector, rectified, amplified, compared to threshold, and reapplied positively or negatively to motor excitation circuit. Speed control reduces wow and flutter of audio turntables and tape recorders, and enhances hunting in gyroscope motors.

  20. Zigzag Connected Autotransformer-Based 24-pulse AC-DC Converter

    NASA Astrophysics Data System (ADS)

    Xiao-qiang, Chen; Hao, Qiu

    2015-02-01

    In this paper, a zigzag connected autotransformer-based 24-pulse AC-DC converter is designed, modeled and simulated to feed direct torque controlled induction motor drives. Winding arrangements and parameters of the autotransformer and interphase reactor are given. Moreover, the design procedure of the autotransformer is modified to make it suitable for retrofit applications. Simulation results indicate that the system is capable of eliminating up to 21st harmonics in the ac mains current. The effect of load variation and load character is also studied to demonstrate the performance and effectiveness of the proposed 24-pulse converters. A set of power quality indices at ac mains and dc side are presented to compare the performance of 6-, 12- and 24-pulse converters.

  1. System and method for motor speed estimation of an electric motor

    DOEpatents

    Lu, Bin; Yan, Ting; Luebke, Charles John; Sharma, Santosh Kumar

    2012-06-19

    A system and method for a motor management system includes a computer readable storage medium and a processing unit. The processing unit configured to determine a voltage value of a voltage input to an alternating current (AC) motor, determine a frequency value of at least one of a voltage input and a current input to the AC motor, determine a load value from the AC motor, and access a set of motor nameplate data, where the set of motor nameplate data includes a rated power, a rated speed, a rated frequency, and a rated voltage of the AC motor. The processing unit is also configured to estimate a motor speed based on the voltage value, the frequency value, the load value, and the set of nameplate data and also store the motor speed on the computer readable storage medium.

  2. Frequency modulation drive for a piezoelectric motor

    DOEpatents

    Mittas, Anthony

    2001-01-01

    A piezoelectric motor has peak performance at a specific frequency f.sub.1 that may vary over a range of frequencies. A drive system is disclosed for operating such a motor at peak performance without feedback. The drive system consists of the motor and an ac source connected to power the motor, the ac source repeatedly generating a frequency over a range from f.sub.1 -.DELTA.x to f.sub.1 +.DELTA.y.

  3. Motor degradation prediction methods

    SciTech Connect

    Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

    1996-12-01

    Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor`s duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures.

  4. Drive control and position measurement of RailCab vehicles driven by linear motors

    NASA Astrophysics Data System (ADS)

    Pottharst, Andreas; Henke, Christian; Schneider, Tobias; Böcker, Joachim; Grotstollen, Horst

    2006-11-01

    The novel railway system RailCab makes use of autonomous vehicles which are driven by an AC linear motor. Depending on the track-side motor part, long-stator or short-stator operations are possible. The paper deals with the operation of the doubly-fed induction motor which is used for motion control and for transferring the energy required onboard the vehicle. This type of linear motor synchronization of the traveling fields generated by the stationary primary and moving secondary windings is an important and demanding task because the instantaneous positions of the vehicle or the primary traveling wave must be determined with high accuracy. The paper shows how this task is solved at the moment and what improvements are under development.

  5. Dietary quinic acid supplied as the nutritional supplement AIO + AC-11® leads to induction of micromolar levels of nicotinamide and tryptophan in the urine.

    PubMed

    Pero, Ronald W; Lund, Harald

    2011-06-01

    Hippuric acid is synthesized and produced primarily by the gastrointestinal (GI) microflora. However, there is no known health benefit for hippuric acid except its catabolic conjugation of benzene-type compounds via glycine and subsequent excretion in the urine. For years the GI tract microflora were known to metabolize quinic acid to hippuric acid. Recently it was also proposed that DNA repair was strongly enhanced by quinic acid. In order to explain these quinic acid effects, Pero and colleagues have examined whether tryptophan and nicotinamide were also enhanced by quinic acid levels in urine. They were indeed, and so another study was designed using a natural supplement source of quinic acid called AIO + AC-11®, and then the effects of intervention were measured after only 21 days. It was possible to show profound increases in quinic acid that were again paralleled by increases in tryptophan and nicotinamide urinary levels. Because the high pressure liquid chromatography (HPLC) methods differed greatly between the two studies, differences in chemical analyses probably did not contribute to the data base. PMID:21104945

  6. An improved FEM model for computing transport AC loss in coils made of RABiTS YBCO coated conductors for electric machines

    NASA Astrophysics Data System (ADS)

    Ainslie, Mark D.; Rodriguez-Zermeno, Victor M.; Hong, Zhiyong; Yuan, Weijia; Flack, Timothy J.; Coombs, Timothy A.

    2011-04-01

    AC loss can be a significant problem for any applications that utilize or produce an AC current or magnetic field, such as an electric machine. The authors investigate the electromagnetic properties of high temperature superconductors with a particular focus on the AC loss in superconducting coils made from YBCO coated conductors for use in an all-superconducting electric machine. This paper presents an improved 2D finite element model for the cross-section of such coils, based on the H formulation. The model is used to calculate the transport AC loss of a racetrack-shaped coil using constant and magnetic field-dependent critical current densities, and the inclusion and exclusion of a magnetic substrate, as found in RABiTS (rolling-assisted biaxially textured substrate) YBCO coated conductors. The coil model is based on the superconducting stator coils used in the University of Cambridge EPEC Superconductivity Group's all-superconducting permanent magnet synchronous motor design. To validate the modeling results, the transport AC loss of a stator coil is measured using an electrical method based on inductive compensation by means of a variable mutual inductance. Finally, the implications of the findings on the performance of the motor are discussed.

  7. Phase and speed synchronization control of four eccentric rotors driven by induction motors in a linear vibratory feeder with unknown time-varying load torques using adaptive sliding mode control algorithm

    NASA Astrophysics Data System (ADS)

    Kong, Xiangxi; Zhang, Xueliang; Chen, Xiaozhe; Wen, Bangchun; Wang, Bo

    2016-05-01

    In this paper, phase and speed synchronization control of four eccentric rotors (ERs) driven by induction motors in a linear vibratory feeder with unknown time-varying load torques is studied. Firstly, the electromechanical coupling model of the linear vibratory feeder is established by associating induction motor's model with the dynamic model of the system, which is a typical under actuated model. According to the characteristics of the linear vibratory feeder, the complex control problem of the under actuated electromechanical coupling model converts to phase and speed synchronization control of four ERs. In order to keep the four ERs operating synchronously with zero phase differences, phase and speed synchronization controllers are designed by employing adaptive sliding mode control (ASMC) algorithm via a modified master-slave structure. The stability of the controllers is proved by Lyapunov stability theorem. The proposed controllers are verified by simulation via Matlab/Simulink program and compared with the conventional sliding mode control (SMC) algorithm. The results show the proposed controllers can reject the time-varying load torques effectively and four ERs can operate synchronously with zero phase differences. Moreover, the control performance is better than the conventional SMC algorithm and the chattering phenomenon is attenuated. Furthermore, the effects of reference speed and parametric perturbations are discussed to show the strong robustness of the proposed controllers. Finally, experiments on a simple vibratory test bench are operated by using the proposed controllers and without control, respectively, to validate the effectiveness of the proposed controllers further.

  8. Ac traction gets on track

    SciTech Connect

    O`Connor, L.

    1995-09-01

    This article describes inverter-based ac traction systems which give freight locomotives greater adhesion, pulling power, and braking capacity. In the 1940s, dc traction replaced the steam engine as a source of train propulsion, and it has ruled the freight transportation industry ever since. But now, high-performance ac-traction systems, with their unprecedented levels of pulling power and adhesion, are becoming increasingly common on America`s freight railroads. In thousands of miles of demonstration tests, today`s ac-traction systems have outperformed traditional dc-motor driven systems. Major railroad companies are convinced enough of the benefits of ac traction to have integrated it into their freight locomotives.

  9. Ultra-Efficient and Power-Dense Electric Motors

    SciTech Connect

    2009-01-01

    This factsheet describes a research project whose goal is to develop line-start and line-run constant-speed electric motors and simple-to-control electric motors with the goal of obtaining at least a 30% reduction in motor losses as compared to conventional energy-efficient induction motors and a 15% reduction in motor losses as compared to NEMA Premium® efficient induction motors.

  10. Recent Advances of Reluctance Torque Assisted Motors

    NASA Astrophysics Data System (ADS)

    Ohyama, Kazunobu

    The history of motor technology began with the discovery of electromagnetic induction by Faraday. Various kinds of motors were developed by the recent progress of the fundamental technology (magnetic structure, magnetic material, drive circuit, control method). Especially, motors using the reluctance torque have many advantages and some of them are used as high efficient motors. This paper overviews recent advances of reluctance torque assisted motors such as Switched Reluctance Motor (SRM), Synchronous Reluctance Motor (SynRM) and Interior Permanent Magnet Synchronous Motor (IPMSM).

  11. Potential applications of photovoltaic energy for pumping and desalting Australian groundwater using brushless DC motors

    SciTech Connect

    Longrigg, P.

    1984-08-01

    This paper discusses methods and techniques for transporting and desalting groundwater supplies using the renewable energy derived from solar photovoltaic systems. The reliability of this type of equipment is emphasized, which operates in remote areas far from other power supplies and maintenance facilities. Until relatively recently, the cost of photovoltaic arrays in remote areas, compared with thermal methods of desalination, precluded their use. But recent developments in photovoltaic technology have changed this. The use of brushless dc motors directly coupled to the PV array eliminates the cost of inverter power conditioning required for ac induction motors. The PV/brushless dc motor configuration yields a particularly good technical fit for pumping and desalting groundwater in the Australian Outback.

  12. An AC-electromagnetic bearing for flywheel energy storage in space

    NASA Astrophysics Data System (ADS)

    Nikolajsen, Jorgen L.

    A repulsive type AC-electromagnetic bearing was developed and tested. It was conceived on the basis of the so-called Magnetic River suspension for high-speed trains. The appearance of the bearing is similar to the traditional DC-type electromagnetic bearing but the operating principle is different. The magnets are fed with alternating current instead of direct current and the rotor is fitted with a conducting sleeve (e.g. aluminum) instead of a ferromagnetic sleeve. The repulsion is due to induction of eddy-currents in the conducting sleeve. The bearing is inherently stable and requires no feedback control. It provides support in five degrees of freedom such that a short rotor may be fully supported by a single bearing. These capabilities were demonstrated experimentally. On the down side, the load carrying capacity and the damping obtained so far were quite low compared to the DC-type bearing. Also, significant heating of the conducting sleeve was experienced. The AC-bearing is essentially a modified induction motor and there are strong indications that it can be run both as a motor and as a generator with no commutator requirements. It is therefore considered to be a good candidate for support of energy storage flywheels in space.

  13. An AC-electromagnetic bearing for flywheel energy storage in space

    NASA Technical Reports Server (NTRS)

    Nikolajsen, Jorgen L.

    1993-01-01

    A repulsive type AC-electromagnetic bearing was developed and tested. It was conceived on the basis of the so-called Magnetic River suspension for high-speed trains. The appearance of the bearing is similar to the traditional DC-type electromagnetic bearing but the operating principle is different. The magnets are fed with alternating current instead of direct current and the rotor is fitted with a conducting sleeve (e.g. aluminum) instead of a ferromagnetic sleeve. The repulsion is due to induction of eddy-currents in the conducting sleeve. The bearing is inherently stable and requires no feedback control. It provides support in five degrees of freedom such that a short rotor may be fully supported by a single bearing. These capabilities were demonstrated experimentally. On the down side, the load carrying capacity and the damping obtained so far were quite low compared to the DC-type bearing. Also, significant heating of the conducting sleeve was experienced. The AC-bearing is essentially a modified induction motor and there are strong indications that it can be run both as a motor and as a generator with no commutator requirements. It is therefore considered to be a good candidate for support of energy storage flywheels in space.

  14. Mountain Plains Learning Experience Guide: Electric Motor Repair.

    ERIC Educational Resources Information Center

    Ziller, T.

    This Electric Motor Repair Course is designed to provide the student with practical information for winding, repairing, and troubleshooting alternating current and direct current motors, and controllers. The course is comprised of eight units: (1) Electric Motor Fundamentals, (2) Rewinding, (3) Split-phase Induction Motors, (4) Capacitor Motors,…

  15. System and component design and test of a 10 hp, 18,000 rpm AC dynamometer utilizing a high frequency AC voltage link, part 1

    NASA Astrophysics Data System (ADS)

    Lipo, Thomas A.; Alan, Irfan

    1991-06-01

    Hard and soft switching test results conducted with one of the samples of first generation MOS-controlled thyristor (MCTs) and similar test results with several different samples of second generation MCT's are reported. A simple chopper circuit is used to investigate the basic switching characteristics of MCT under hard switching and various types of resonant circuits are used to determine soft switching characteristics of MCT under both zero voltage and zero current switching. Next, operation principles of a pulse density modulated converter (PDMC) for three phase (3F) to 3F two-step power conversion via parallel resonant high frequency (HF) AC link are reviewed. The details for the selection of power switches and other power components required for the construction of the power circuit for the second generation 3F to 3F converter system are discussed. The problems encountered in the first generation system are considered. Design and performance of the first generation 3F to 3F power converter system and field oriented induction moter drive based upon a 3 kVA, 20 kHz parallel resonant HF AC link are described. Low harmonic current at the input and output, unity power factor operation of input, and bidirectional flow capability of the system are shown via both computer and experimental results. The work completed on the construction and testing of the second generation converter and field oriented induction motor drive based upon specifications for a 10 hp squirrel cage dynamometer and a 20 kHz parallel resonant HF AC link is discussed. The induction machine is designed to deliver 10 hp or 7.46 kW when operated as an AC-dynamo with power fed back to the source through the converter. Results presented reveal that the proposed power level requires additional energy storage elements to overcome difficulties with a peak link voltage variation problem that limits reaching to the desired power level. The power level test of the second generation converter after the

  16. System and component design and test of a 10 hp, 18,000 rpm AC dynamometer utilizing a high frequency AC voltage link, part 1

    NASA Technical Reports Server (NTRS)

    Lipo, Thomas A.; Alan, Irfan

    1991-01-01

    Hard and soft switching test results conducted with one of the samples of first generation MOS-controlled thyristor (MCTs) and similar test results with several different samples of second generation MCT's are reported. A simple chopper circuit is used to investigate the basic switching characteristics of MCT under hard switching and various types of resonant circuits are used to determine soft switching characteristics of MCT under both zero voltage and zero current switching. Next, operation principles of a pulse density modulated converter (PDMC) for three phase (3F) to 3F two-step power conversion via parallel resonant high frequency (HF) AC link are reviewed. The details for the selection of power switches and other power components required for the construction of the power circuit for the second generation 3F to 3F converter system are discussed. The problems encountered in the first generation system are considered. Design and performance of the first generation 3F to 3F power converter system and field oriented induction moter drive based upon a 3 kVA, 20 kHz parallel resonant HF AC link are described. Low harmonic current at the input and output, unity power factor operation of input, and bidirectional flow capability of the system are shown via both computer and experimental results. The work completed on the construction and testing of the second generation converter and field oriented induction motor drive based upon specifications for a 10 hp squirrel cage dynamometer and a 20 kHz parallel resonant HF AC link is discussed. The induction machine is designed to deliver 10 hp or 7.46 kW when operated as an AC-dynamo with power fed back to the source through the converter. Results presented reveal that the proposed power level requires additional energy storage elements to overcome difficulties with a peak link voltage variation problem that limits reaching to the desired power level. The power level test of the second generation converter after the

  17. Delocalization of the Microtubule Motor Dynein from Mitotic Spindles by the Human Papillomavirus E7 Oncoprotein is Not Sufficient for Induction of Multipolar Mitoses

    PubMed Central

    Nguyen, Christine L.; McLaughlin-Drubin, Margaret E.; Münger, Karl

    2008-01-01

    Dynein is a minus-end directed microtubule motor that transports numerous cargoes throughout the cell. During mitosis, dynein motor activity is necessary for the positioning of spindle microtubules and has also been implicated in inactivating the spindle assembly checkpoint. Mutations in dynein motor and/or accessory proteins are associated with human disease, including cancer, and the delocalization of dynein from mitotic spindles has been correlated with an increased incidence of multipolar spindle formation in some cancer cells that contain supernumerary centrosomes. The high-risk human papillomavirus type 16 (HPV16) E7 oncoprotein induces centrosome overduplication and has been shown to cause multipolar mitotic spindle formation, a diagnostic hallmark of HPV-associated neoplasias. Here we show that HPV16 E7 expression leads to an increased population of mitotic cells with dynein delocalized from the mitotic spindle. This function maps to sequences of HPV16 E7 that are distinct from the region necessary for centrosome overduplication. However, contrary to previous reports, we provide evidence that dynein delocalization by HPV16 E7 is neither necessary nor sufficient to cause the formation of multipolar mitoses. PMID:18974113

  18. Prediction of torque and inductance displacement characteristics of asymmetrically slotted variable-reluctance motors using a simplified model for numerical field solution

    SciTech Connect

    Ertan, H.B.

    1999-09-01

    For prediction of static and dynamic performance of doubly-salient motors, it is essential to know their flux linkage-position-excitation characteristics and also the static torque characteristics. At the design stage determination of these characteristics presents difficulties because of highly nonlinear behavior of the magnetic circuit. It is possible to use numerical field solution of the complete motor to obtain this information. This, however, requires expertise on a professional program and may be expensive if used to search for the best design. This paper shows that a reduced model can be used to obtain the desired information accurately. It is also shown that in fact obtaining field solutions just for a pair of teeth is enough for accurately predicting the flux linkage and torque characteristics of a motor. The approach introduced here makes possible searching for an optimum design (even on a PC) for maximizing average torque or reducing noise and vibration problems, since the effort for producing the model and computation time are greatly reduced.

  19. Parametric electric motor study

    SciTech Connect

    Adams, D.; Stahura, D.

    1995-04-30

    Technology for the axial gap motor was developed by DOE with an investment of approximately $15 million. This development effort is for motor technologies of high power density and high efficiency. Such motors that are also small and light-weight are not available on the commercial market because high-power motors have typically been used in large industrial applications where small size and light weight are not requirements. AC Delco has been developing motors since 1918 and is interested in leveraging its research and development dollars to produce an array of motor systems for vehicles and to develop a future line of propulsion products. The DOE focus of the study was applied to machining applications. The most attractive feature of this motor is the axial air gap, which may make possible the removal of the motor`s stationary component from a total enclosure of the remainder of the machine if the power characteristics are adequate. The objectives of this project were to evaluate alternative electric drive systems for machine tools and automotive electric drive systems and to select a best machine type for each of those applications. A major challenge of this project was to produce a small, light-weight, highly efficient motor at a cost-effective price. The project developed machine and machine drive systems and design criteria for the range of applications. The final results included the creation of a baseline for developing electric vehicle powertrain system designs, conventional vehicle engine support system designs, and advanced machine tool configurations. In addition, an axial gap permanent magnet motor was built and tested, and gave, said one engineer involved, a sterling performance. This effort will commercialize advanced motor technology and extend knowledge and design capability in the most efficient electric machine design known today.

  20. Reducing current reversal time in electric motor control

    SciTech Connect

    Bredemann, Michael V

    2014-11-04

    The time required to reverse current flow in an electric motor is reduced by exploiting inductive current that persists in the motor when power is temporarily removed. Energy associated with this inductive current is used to initiate reverse current flow in the motor.

  1. Agricultural Electricity. Electric Motors. Student Manual.

    ERIC Educational Resources Information Center

    Benson, Robert T.

    Addressed to the student, this manual, which includes supplementary diagrams, discusses the following topics and principles: Electromagnetic fields, electromagnets, parts of an electric motor, determining speed of an electric motor, types of electric motors in common use (split-phase, capacitor, repulsion-induction, three-phase), the electric…

  2. Experimental Verification for Stability Improvement of Sensor-less Vector Control System of Induction Motor Using Real Time Tuning of Observer Gain

    NASA Astrophysics Data System (ADS)

    Ohyama, Kazuhiro; Hamaoka, Teruo; Asher, Greg; Sumner, Mark

    This paper proposes the design method of adaptive rotor flux observer gain to improve stability at low speed and regenerating mode. The method is based on the stability analysis. The stability analysis utilizes the linearized model considering all systems including each control loop. Therefore the proposed method considers the effects of motor constants and control circuit constants. The stability analysis using the transfer function for rotor speed considers the arrangement of pole and zero and the steady state error. The rotor flux observer gain which improves the stability for each operating condition is clarified. Also this paper proposes the real time tuning method of observer gain. The validity of the proposed method is confirmed on the simulation using Matlab Simulink and the experiment.

  3. Induction of Neuron-Specific Degradation of Coenzyme A Models Pantothenate Kinase-Associated Neurodegeneration by Reducing Motor Coordination in Mice

    PubMed Central

    Shumar, Stephanie A.; Fagone, Paolo; Alfonso-Pecchio, Adolfo; Gray, John T.; Rehg, Jerold E.; Jackowski, Suzanne; Leonardi, Roberta

    2015-01-01

    Background Pantothenate kinase-associated neurodegeneration, PKAN, is an inherited disorder characterized by progressive impairment in motor coordination and caused by mutations in PANK2, a human gene that encodes one of four pantothenate kinase (PanK) isoforms. PanK initiates the synthesis of coenzyme A (CoA), an essential cofactor that plays a key role in energy metabolism and lipid synthesis. Most of the mutations in PANK2 reduce or abolish the activity of the enzyme. This evidence has led to the hypothesis that lower CoA might be the underlying cause of the neurodegeneration in PKAN patients; however, no mouse model of the disease is currently available to investigate the connection between neuronal CoA levels and neurodegeneration. Indeed, genetic and/or dietary manipulations aimed at reducing whole-body CoA synthesis have not produced a desirable PKAN model, and this has greatly hindered the discovery of a treatment for the disease. Objective, Methods, Results and Conclusions Cellular CoA levels are tightly regulated by a balance between synthesis and degradation. CoA degradation is catalyzed by two peroxisomal nudix hydrolases, Nudt7 and Nudt19. In this study we sought to reduce neuronal CoA in mice through the alternative approach of increasing Nudt7-mediated CoA degradation. This was achieved by combining the use of an adeno-associated virus-based expression system with the synapsin (Syn) promoter. We show that mice with neuronal overexpression of a cytosolic version of Nudt7 (scAAV9-Syn-Nudt7cyt) exhibit a significant decrease in brain CoA levels in conjunction with a reduction in motor coordination. These results strongly support the existence of a link between CoA levels and neuronal function and show that scAAV9-Syn-Nudt7cyt mice can be used to model PKAN. PMID:26052948

  4. Advanced Ultra-High Speed Motor for Drilling

    SciTech Connect

    Impact Technologies LLC; University of Texas at Arlington

    2007-03-31

    Three (3) designs have been made for two sizes, 6.91 cm (2.72 inch) and 4.29 cm (1.69 inch) outer diameters, of a patented inverted configured Permanent Magnet Synchronous Machines (PMSM) electric motor specifically for drilling at ultra-high rotational speeds (10,000 rpm) and that can utilize advanced drilling methods. Benefits of these motors are stackable power sections, full control (speed and direction) of downhole motors, flow hydraulics independent of motor operation, application of advanced drilling methods (water jetting and abrasive slurry jetting), and the ability of signal/power electric wires through motor(s). Key features of the final designed motors are: fixed non-rotating shaft with stator coils attached; rotating housing with permanent magnet (PM) rotor attached; bit attached to rotating housing; internal channel(s) in a nonrotating shaft; electric components that are hydrostatically isolated from high internal pressure circulating fluids ('muds') by static metal to metal seals; liquid filled motor with smoothed features for minimized turbulence in the motor during operation; and new inverted coated metal-metal hydrodynamic bearings and seals. PMSM, Induction and Switched Reluctance Machines (SRM), all pulse modulated, were considered, but PMSM were determined to provide the highest power density for the shortest motors. Both radial and axial electric PMSM driven motors were designed with axial designs deemed more rugged for ultra-high speed, drilling applications. The 6.91 cm (2.72 inch) OD axial inverted motor can generate 4.18KW (5.61 Hp) power at 10,000 rpm with a 4 Nm (2.95 ft-lbs) of torque for every 30.48 cm (12 inches) of power section. The 6.91 cm (2.72 inch) OD radial inverted motor can generate 5.03 KW (6.74 Hp) with 4.8 Nm (3.54 ft-lb) torque at 10,000 rpm for every 30.48 cm (12 inches) of power section. The 4.29 cm (1.69 inch) OD radial inverted motor can generate 2.56 KW (3.43 Hp) power with 2.44 Nm (1.8 ft-lb) torque at full speed 10

  5. Labor Induction

    MedlinePlus

    ... QUESTIONS FAQ154 LABOR, DELIVERY, AND POSTPARTUM CARE Labor Induction • What is labor induction? • Why is labor induced? • What is the Bishop ... oxytocin? • What are the risks associated with labor induction? • Is labor induction always effective? • Glossary What is ...

  6. Rotor position sensor switches currents in brushless dc motors

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Reluctance switch incorporated in an induction motor is used for sensing rotor position and switching armature circuits in a brushless dc motor. This device drives the solar array system of an unmanned space satellite.

  7. Neuronal mechanisms of motor learning and motor memory consolidation in healthy old adults.

    PubMed

    Berghuis, K M M; Veldman, M P; Solnik, S; Koch, G; Zijdewind, I; Hortobágyi, T

    2015-06-01

    It is controversial whether or not old adults are capable of learning new motor skills and consolidate the performance gains into motor memory in the offline period. The underlying neuronal mechanisms are equally unclear. We determined the magnitude of motor learning and motor memory consolidation in healthy old adults and examined if specific metrics of neuronal excitability measured by magnetic brain stimulation mediate the practice and retention effects. Eleven healthy old adults practiced a wrist extension-flexion visuomotor skill for 20 min (MP, 71.3 years), while a second group only watched the templates without movements (attentional control, AC, n = 11, 70.5 years). There was 40 % motor learning in MP but none in AC (interaction, p < 0.001) with the skill retained 24 h later in MP and a 16 % improvement in AC. Corticospinal excitability at rest and during task did not change, but when measured during contraction at 20 % of maximal force, it strongly increased in MP and decreased in AC (interaction, p = 0.002). Intracortical inhibition at rest and during the task decreased and facilitation at rest increased in MP, but these metrics changed in the opposite direction in AC. These neuronal changes were especially profound at retention. Healthy old adults can learn a new motor skill and consolidate the learned skill into motor memory, processes that are most likely mediated by disinhibitory mechanisms. These results are relevant for the increasing number of old adults who need to learn and relearn movements during motor rehabilitation. PMID:25956604

  8. The Ball Bearing as a Motor.

    ERIC Educational Resources Information Center

    Gruenberg, H.

    1978-01-01

    Develops a theory to explain the effect that, when a current passes through a ball bearing, it can act as a motor. The motor can run in either direction on both DC and AC and can be self-starting on DC. Presents some experimental results in support of the theory. (Author/GA)

  9. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false AC-powered adjustable hospital bed. 880.5100... Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered... electric motor and remote controls that can be operated by the patient to adjust the height and...

  10. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false AC-powered adjustable hospital bed. 880.5100... Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered... electric motor and remote controls that can be operated by the patient to adjust the height and...

  11. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false AC-powered adjustable hospital bed. 880.5100... Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered... electric motor and remote controls that can be operated by the patient to adjust the height and...

  12. 21 CFR 880.5100 - AC-powered adjustable hospital bed.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false AC-powered adjustable hospital bed. 880.5100... Therapeutic Devices § 880.5100 AC-powered adjustable hospital bed. (a) Identification. An AC-powered... electric motor and remote controls that can be operated by the patient to adjust the height and...

  13. Trade Electricity. Motors & Controls--Level 3. Standardized Curriculum.

    ERIC Educational Resources Information Center

    New York City Board of Education, Brooklyn, NY. Office of Occupational and Career Education.

    This curriculum guide consists of seven modules on motors and controls, one of the three divisions of the standardized trade electricity curriculum in high schools in New York City. The seven modules cover the following subjects: energy conservation wiring, direct current (DC) motor repair and rewinding, DC motor controls, alternating current (AC)…

  14. Power-Quality Improvement in PFC Bridgeless SEPIC-Fed BLDC Motor Drive

    NASA Astrophysics Data System (ADS)

    Singh, Bhim; Bist, Vashist

    2013-06-01

    This article presents a design of a power factor correction (PFC)-based brushless DC (BLDC) motor drive. The speed control of BLDC motor is achieved by controlling the DC link voltage of the voltage source inverter (VSI) feeding BLDC motor using a single voltage sensor. A front-end bridgeless single-ended primary inductance converter (SEPIC) is used for DC link voltage control and PFC operation. A bridgeless SEPIC is designed to operate in discontinuous inductor current mode (DICM) thus utilizing a simple control scheme of voltage follower. An electronic commutation of BLDC motor is used for VSI to operate in a low-frequency operation for reduced switching losses in the VSI. Moreover, a bridgeless topology offers less conduction losses due to absence of diode bridge rectifier for further increasing the efficiency. The proposed BLDC motor drive is designed to operate over a wide range of speed control with an improved power-quality at the AC mains under the recommended international power-quality standards such as IEC 61000-3-2.

  15. A Passive EMI Filter Requiring Access to the Ungrounded Motor-Neutral Line

    NASA Astrophysics Data System (ADS)

    Oe, Takehiko; Akagi, Hirofumi

    The authors have already proposed a passive EMI filter that does require access to the motor-neutral point. The EMI filter has been applied to an induction motor driven by a voltage-source PWM inverter with a three-phase diode rectifier used as the front end. Experimental results have shown that the EMI filter can mitigate leakage currents flowing out of the motor and the heat sink, as well as bearing currents circulating inside the motor. This paper deals with a passive EMI filter for preventing high-frequency leakage currents from flowing through the heat sink of a voltage-source PWM inverter together with a voltage-source PWM rectifier used as the front end. Both rectifier and inverter have the same carrier frequency as 14kHz. The tested motor equipped with the motor-neutral line is an interior permanent magnet synchronous motor (IPM-SM) rated at 190V, 5.5kW, 6 poles and 1,800rpm. This paper designs, constructs and tests two types of EMI filters. These filters consist mainly of two 10-mH identical common-mode inductors that are installed on the ac sides of the rectifier and the inverter, respectively. However, the two filters are slightly different in that one accesses to the dc-link mid-point, and the other does not access to it. Experimental waveforms verify that the former is superior to the latter in eliminating the high-frequency leakage currents from both the heat sink and the motor.

  16. Composite ceramic superconducting wires for electric-motor applications. Quarterly report No. 3, 31 January 1989-31 March 1989

    SciTech Connect

    Halloran, J.W.

    1989-04-28

    This report describes progress on developing Y-123 wire for an HTSC motor. The wire is produced by spinning and heat treating fiber to produce metallized superconducting filaments. Development continued on spinning Y-123 green fiber. The diameter of continuous Y-123 green fiber was reduced to 75 microns. A belt furnace is being reconfigured for continuous sintering of fibers and a prototype cladding module for multi-filament ribbon wire is being fabricated. There has been an improvement in 77 K (self-field) critical current density of Y-123 filaments, up to 2400A/sq cm for the best filament, with 1500 A/sq cm for a typical filament. Similar results are seen for silver clad filaments. Preliminary data suggests an important effect of specimen length on transport critical current of thin filaments of weak-linked specimens. At Emerson Electric the characteristics of DC homopolar, DC heteropolar, reluctance, and induction HTSC motors were determined theoretically. A DC homopolar and an induction motor with superconducting stator windings were selected as final candidates for the proof-of-principle motor. M. Hilal of the University of Wisconsin developed a model for AC losses in HTSC wire, including eddy current and hysteresis losses.

  17. Control of power to an inductively heated part

    DOEpatents

    Adkins, Douglas R.; Frost, Charles A.; Kahle, Philip M.; Kelley, J. Bruce; Stanton, Suzanne L.

    1997-01-01

    A process for induction hardening a part to a desired depth with an AC signal applied to the part from a closely coupled induction coil includes measuring the voltage of the AC signal at the coil and the current passing through the coil; and controlling the depth of hardening of the part from the measured voltage and current. The control system determines parameters of the part that are functions of applied voltage and current to the induction coil, and uses a neural network to control the application of the AC signal based on the detected functions for each part.

  18. Control of power to an inductively heated part

    DOEpatents

    Adkins, D.R.; Frost, C.A.; Kahle, P.M.; Kelley, J.B.; Stanton, S.L.

    1997-05-20

    A process for induction hardening a part to a desired depth with an AC signal applied to the part from a closely coupled induction coil includes measuring the voltage of the AC signal at the coil and the current passing through the coil; and controlling the depth of hardening of the part from the measured voltage and current. The control system determines parameters of the part that are functions of applied voltage and current to the induction coil, and uses a neural network to control the application of the AC signal based on the detected functions for each part. 6 figs.

  19. Motor-operated valve (MOV) actuator motor and gearbox testing

    SciTech Connect

    DeWall, K.; Watkins, J.C.; Bramwell, D.

    1997-07-01

    Researchers at the Idaho National Engineering and Environmental Laboratory tested the performance of electric motors and actuator gearboxes typical of the equipment installed on motor-operated valves used in nuclear power plants. Using a test stand that simulates valve closure loads against flow and pressure, the authors tested five electric motors (four ac and one dc) and three gearboxes at conditions a motor might experience in a power plant, including such off-normal conditions as operation at high temperature and reduced voltage. They also monitored the efficiency of the actuator gearbox. All five motors operated at or above their rated starting torque during tests at normal voltages and temperatures. For all five motors, actual torque losses due to voltage degradation were greater than the losses calculated by methods typically used for predicting motor torque at degraded voltage conditions. For the dc motor the actual torque losses due to elevated operating temperatures were greater than the losses calculated by the typical predictive method. The actual efficiencies of the actuator gearboxes were generally lower than the running efficiencies published by the manufacturer and were generally nearer the published pull-out efficiencies. Operation of the gearbox at elevated temperature did not affect the operating efficiency.

  20. 27. INTERIOR VIEW LOOKING SOUTHWEST IN THE ELECTRICAL MOTOR ROOM. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. INTERIOR VIEW LOOKING SOUTHWEST IN THE ELECTRICAL MOTOR ROOM. FROM LEFT TO RIGHT. DC GENERATOR, AC MOTOR, OLD DC GENERATOR, OPENING FOR THE BELT TO THE CLUTCH ASSEMBLY FOR THE MILL POWER SYSTEM. THE BOARDS THAT ARE ASKEW WERE PROTECTION AROUND THE DRIVE BELT. THE SMALL MOTOR IN THE FOREGROUND IS THE MOTOR THAT MOST RECENTLY POWERED THE MILL'S BELT DRIVE SYSTEM. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  1. A linearly controlled direct-current power source for high-current inductive loads in a magnetic suspension wind tunnel

    NASA Technical Reports Server (NTRS)

    Tripp, John S.; Daniels, Taumi S.

    1990-01-01

    The NASA Langley 6 inch magnetic suspension and balance system (MSBS) requires an independently controlled bidirectional DC power source for each of six positioning electromagnets. These electromagnets provide five-degree-of-freedom control over a suspended aerodynamic test model. Existing power equipment, which employs resistance coupled thyratron controlled rectifiers as well as AC to DC motor generator converters, is obsolete, inefficient, and unreliable. A replacement six phase bidirectional controlled bridge rectifier is proposed, which employs power MOSFET switches sequenced by hybrid analog/digital circuits. Full load efficiency is 80 percent compared to 25 percent for the resistance coupled thyratron system. Current feedback provides high control linearity, adjustable current limiting, and current overload protection. A quenching circuit suppresses inductive voltage impulses. It is shown that 20 kHz interference from positioning magnet power into MSBS electromagnetic model position sensors results predominantly from capacitively coupled electric fields. Hence, proper shielding and grounding techniques are necessary. Inductively coupled magnetic interference is negligible.

  2. ACS Quicklook PDF products

    NASA Astrophysics Data System (ADS)

    Suchkov, Anatoly

    1999-12-01

    This report details the features of the ACS quicklook PDF products produced by the HST data pipeline. The requirements closely follow the design of paper products recommended by the Data Quality Committee, with appropriate changes required to fully support ACS.

  3. Parameter measurement of synchronous reluctance motor using LC resonance

    NASA Astrophysics Data System (ADS)

    Ahn, Joonseon; Kim, Ki-Chan; Lee, Ju

    2006-04-01

    The motor characterizing parameters are most important factors to drive precisely, effectively, and robustly. Especially, the exact knowledge of synchronous inductance is necessary to control the torque precisely in synchronous reluctance motor (SynRM). Therefore many works have been done for the exact measurement of motor parameters. In this paper, we propose the simple method of measuring the motor parameters, especially measuring the synchronous inductance of SynRM, which can overcome the demerits of conventional methods and measure the exact values. The proposed method uses the resonance phenomenon between the phase inductance and capacitors externally connected.

  4. Motor considerations for turbomachinery

    SciTech Connect

    Halfpap, R.F.; Brotherhood, R. )

    1995-02-01

    Customers who use large rotating equipment realize motors can be subjected to hostile environmental conditions, nonstandard voltage levels and a variety of load requirements. The motor specifications they write reflect this change and have become far more detailed. Too often in the past, when large projects were being organized and highly technical equipment purchased, induction motors were thought of as standard pieces of equipment not requiring much in the way of specialized design. High-speed compressor applications are good examples of the need for specific compressor torque characteristics and starting requirements to allow for proper motor design. Not only different compressor designs, but adjustments in compressor valves and changes in gas process conditions, can produce a diversity of speed-torque curves. Therefore, it is not practical for a motor designer to be told to assume a standard compressor load torque during acceleration. An example of compressor speed-torque curves illustrates this point. The paper also presents the example of centrifugal pumps to further illustrate the need for properly matching driver torque and power requirements.

  5. Efficiency Measurement Using a Motor-Dynamo Module

    ERIC Educational Resources Information Center

    Ng, Pun-hon; Wong, Siu-ling; Mak, Se-yuen

    2009-01-01

    In this article, we describe a simple method which can be used to measure the efficiency of a low power dc motor, a motor-converted dynamo and a coupled motor-dynamo module as a function of the speed of rotation. The result can also be used to verify Faraday's law of electromagnetic induction. (Contains 1 table and 8 figures.)

  6. Basic properties of a single-phase hybrid motor prototype

    NASA Astrophysics Data System (ADS)

    Goleman, R.

    1996-07-01

    The prototype hybrid motor is a new structure consisting of a combination of a magnetic frequency tripler and an induction motor. This paper presents the structure, operation and basic properties of the motor prototype. The prototype is illustrated by the results of experimental investigations, i.e. speed-time curves and torque characteristics.

  7. Motor Starters

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The power factor controller (PFC) was invented by a NASA engineer. It matches voltage with a motor's actual need by sensing shifts in the relationship between voltage and current flow. With the device, power can be trimmed as much as 65%. Intellinet adopted this technology and designed "soft start" and "load-responsive" control modes to start engines gradually and recycle voltage without reducing motor speed. Other features are lower motor heat and faster fault identification.

  8. Motor syndromes.

    PubMed

    Corea, Francesco; Micheli, Sara

    2012-01-01

    Motor disturbances alone or associated with other focal deficits are the most common symptoms suggesting a neurovascular event. An appropriate clinical assessment of these signs and symptoms may help physicians to better diagnose and to both better treat and predict outcome. In this paper the main clinical features of motor deficit are described together with other motor-related events such as ataxia and movement disturbances. PMID:22377850

  9. LTD, RP, and Motor Learning.

    PubMed

    Hirano, Tomoo; Yamazaki, Yoshito; Nakamura, Yoji

    2016-02-01

    Long-term depression (LTD) at excitatory synapses between parallel fibers and a Purkinje cell has been regarded as a critical cellular mechanism for motor learning. However, it was demonstrated that normal motor learning occurs under LTD suppression, suggesting that cerebellar plasticity mechanisms other than LTD also contribute to motor learning. One candidate for such plasticity is rebound potentiation (RP), which is long-term potentiation at inhibitory synapses between a stellate cell and a Purkinje cell. Both LTD and RP are induced by the increase in postsynaptic Ca(2+) concentration, and work to suppress the activity of a Purkinje cell. Thus, LTD and RP might work synergistically, and one might compensate defects of the other. RP induction is dependent on the interaction between GABAA receptor and GABAA receptor binding protein (GABARAP). Transgenic mice expressing a peptide which inhibits binding of GABARAP and GABAA receptor only in Purkinje cells show defects in both RP and adaptation of vestibulo-ocular reflex (VOR), a motor learning paradigm. However, another example of motor learning, adaptation of optokinetic response (OKR), is normal in the transgenic mice. Both VOR and OKR are reflex eye movements suppressing the slip of visual image on the retina during head movement. Previously, we reported that delphilin knockout mice show facilitated LTD induction and enhanced OKR adaptation, but we recently found that VOR adaptation was not enhanced in the knockout mice. These results together suggest that animals might use LTD and RP differently depending on motor learning tasks. PMID:26160222

  10. EXT-II: a second generation advanced ac propulsion system

    SciTech Connect

    Bates, B.; Patil, P.B.; Ciccarelli, M.F.

    1986-01-01

    This paper discusses the characteristics of the concept and includes discussion of the system constraints, including traction battery constraints, and brief descriptions of the major subsystems being developed. The components discussed include: the system controller, dc to ac inverter, an internal permanent magnet ac motor and a two-speed automatic transmission with an integral final drive and differential. The motor and transmission are on a common axis and are integrated into one compact unit that is integral with the rear axle of the vehicle.

  11. Levitation forces in bearingless permanent magnet motors

    SciTech Connect

    Amrhein, W.; Silber, S.; Nenninger, K.

    1999-09-01

    Bearingless motors combine brushless AC-motors with active magnetic bearings by the integration of two separate winding systems (torque and radial levitation force windings with different pole pairs) in one housing. This paper gives an insight into the influences of the motor design on the levitation force and torque generation. It is shown that especially for machines with small air gaps it can be very important to choose the right design parameters. Increasing the permanent magnet height in order to increase the motor torque can result in a remarkable reduction of radial forces. The interrelationships are discussed on the basis of Maxwell and Lorentz forces acting upon the stator surface. The investigations are presented for a bearingless low cost motor, suited for pump, fan or blower applications. The presented motor needs only four coils for operation.

  12. Novel method for driving the ultrasonic motor.

    PubMed

    Kim, Hyeoung woo; Dong, Shuxiang; Laoratanakul, Pitak; Uchino, Kenji; Park, Tae gone

    2002-10-01

    This paper reports a novel driving method for an annular plate-type ultrasonic motor. Instead of the direct current/alternating current (DC/AC) converter type driver using conventional electromagnetic transformer, a compact disc-type piezoelectric transformer is used to obtain high voltage output for driving the ultrasonic motor. The piezoelectric transformer is operated in the radial vibration mode at resonance frequency close to the resonance frequency of the ultrasonic motor. Later, it was found that the piezoelectric transformer could drive the ultrasonic motor, even if their resonance frequencies are not exactly the same by incorporating the matching network in the circuit. The maximum speed of the ultrasonic motor obtained by using this driving method is over 300 rpm. It is believed that the results of this study will have impact on the integration and miniaturization of the ultrasonic motor and its driving circuit. PMID:12403137

  13. A linear magnetic motor and generator

    NASA Technical Reports Server (NTRS)

    Studer, P. A.

    1980-01-01

    In linear magnetic motor and generator suitable for remote and hostile environments, magnetic forces drive reciprocating shaft along its axis. Actuator shaft is located in center of cylindrical body and may be supported by either contacting or noncontacting bearings. When device operates as bidirectional motor, drive coil selectively adds and subtracts magnetic flux to and from flux paths, producing forces that drive actuator along axis. When actuator is driven by external reciprocating engine, device becomes ac generator.

  14. Differential regulation of MUC5AC/Muc5ac and hCLCA-1/mGob-5 expression in airway epithelium.

    PubMed

    Thai, Philip; Chen, Yin; Dolganov, Gregory; Wu, Reen

    2005-12-01

    This study demonstrates that the two biomarkers, MUC5AC/ Muc5ac and hCLCA1/Gob5, which are frequently associated with surface mucous/goblet cells in asthmatic airways, are differentially regulated. Intratracheal instillation of IL-13 (0.5 mug/mouse lung) elicited 8- and 110-fold induction of Muc5ac and Gob5 messages, respectively, within 24 h in wild-type mouse lung, whereas these inductions were abrogated in Stat6 knockout mice. The induction of MUC5AC/Muc5ac message could not be duplicated in vitro with primary tracheobronchial epithelial (TBE) cells derived from wild-type mice or humans, despite significant inductions still seen for hCLCA1/Gob5. Further studies with JAK inhibitors and STAT6 signaling showed active signaling of the JAK/STAT6 pathway in these primary TBE cultures by IL-13 in the regulation of hCLCA1 expression. Dual immunofluorescent staining with antibodies specific to MUC5AC and hCLCA1 revealed a differential nature of the expression of these two biomarkers by distinct cell types of primary TBE cultures. Finally, MUC5AC expression could be elevated by a bacterial product, peptidoglycan, without any induction of hCLCA1. Thus, these results suggest that the two biomakers of the metaplastic airway mucous cell type are differentially regulated by JAK/STAT6-dependent and -independent pathways. PMID:16151054

  15. Molecular motors

    NASA Astrophysics Data System (ADS)

    Allemand, Jean François Desbiolles, Pierre

    2015-10-01

    How do we move? More precisely, what are the molecular mechanisms that can explain that our muscles, made of very small components can move at a osopic scale? To answer these questions we must introduce molecular motors. Those motors are proteins, or small protein assemblies that, in our cells, transform chemical energy into mechanical work. Then, like we could do for a oscopic motor, used in a car or in a fan, we are going to study the basic behavior of these molecular machines, present what are their energy sources, calculate their power, their yield. If molecular motors are crucial for our oscopic movements, we are going to see that they are also essential to cellular transport and that considering the activity of some enzymes as molecular motors bring some interesting new insights on their activity.

  16. Design of a robust modulation controller over a wide range of load characteristics for ac/dc systems

    SciTech Connect

    Choudry, M.A.; Reza, M.A. . Dept. of Electrical Engineering); Ellithy, K.A. )

    1990-02-01

    This paper presents a method to design a robust modulation controller to improve the dynamic performance of ac/dc systems. Static load is modeled as a nonlinear function of load bus voltage and dynamic load is modeled by an equivalent induction motor. Reactive power and dc power are considered for the modulation control. Static var compensator (SVC) is used for the reactive power modulation. The rotor speed and angle deviations of the synchronous generator are used as a stabilizing signal to the SVC. The controller gains are selected based on the eigenvalue sensitivity of electromechanical mode of the closed loop system with respect to load characteristic. Eigenvalue analysis and simulation results show that the proposed reactive power modulation control improves the system response over a wide range of voltage dependent load characteristic as compared with the control using only the rotor speed deviation.

  17. Fuzzy logic controllers for electric motors and wind turbines. Report for October 1996-April 1997

    SciTech Connect

    Spiegel, R.J.

    1997-04-01

    The paper discusses a precision laboratory test facility that has been assempbled to test the performance of two fuzzy-logic based controllers for electric motors and wind turbines. Commercial induction motors up to 10 hp (7.46 kWe) in motors and equipped with adjustable-speed drives (ASDs) were used to test the motor optimizers.

  18. Alternating-Current Motor Drive for Electric Vehicles

    NASA Technical Reports Server (NTRS)

    Krauthamer, S.; Rippel, W. E.

    1982-01-01

    New electric drive controls speed of a polyphase as motor by varying frequency of inverter output. Closed-loop current-sensing circuit automatically adjusts frequency of voltage-controlled oscillator that controls inverter frequency, to limit starting and accelerating surges. Efficient inverter and ac motor would give electric vehicles extra miles per battery charge.

  19. 28. INTERIOR VIEW LOOKING NORTH IN THE ELECTRICAL MOTOR ROOM. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. INTERIOR VIEW LOOKING NORTH IN THE ELECTRICAL MOTOR ROOM. CLOSE UP VIEW OF THE OLD DC GENERATOR, APPARATUS ON THE FLOOR ARE FOR THE OPERATION OF TH DC GENERATOR. AN AC MOTOR IS IN THE BACKGROUND RIGHT. - Standard Gold Mill, East of Bodie Creek, Northeast of Bodie, Bodie, Mono County, CA

  20. FreedomCAR Advanced Traction Drive Motor Development Phase I

    SciTech Connect

    Ley, Josh; Lutz, Jon

    2006-09-01

    The overall objective of this program is to design and develop an advanced traction motor that will meet the FreedomCAR and Vehicle Technologies (FCVT) 2010 goals and the traction motor technical targets. The motor specifications are given in Section 1.3. Other goals of the program include providing a cost study to ensure the motor can be developed within the cost targets needed for the automotive industry. The program has focused on using materials that are both high performance and low costs such that the performance can be met and cost targets are achieved. In addition, the motor technologies and machine design features must be compatible with high volume manufacturing and able to provide high reliability, efficiency, and ruggedness while simultaneously reducing weight and volume. Weight and volume reduction will become a major factor in reducing cost, material cost being the most significant part of manufacturing cost at high volume. Many motor technology categories have been considered in the past and present for traction drive applications, including: brushed direct current (DC), PM (PM) brushless dc (BLDC), alternating current (AC) induction, switched reluctance and synchronous reluctance machines. Of these machine technologies, PM BLDC has consistently demonstrated an advantage in terms of power density and efficiency. As rare earth magnet cost has declined, total cost may also be reduced over the other technologies. Of the many different configurations of PM BLDC machines, those which incorporate power production utilizing both magnetic torque as well as reluctance torque appear to have the most promise for traction applications. There are many different PM BLDC machine configurations which employ both of these torque producing mechanisms; however, most would fall into one of two categories--some use weaker magnets and rely more heavily on reluctance torque (reluctance-dominant PM machines), others use strong PMs and supplement with reluctance torque

  1. Frequency Domain Analysis of Beat-Less Control Method for Converter-Inverter Driving Systems Applied to AC Electric Cars

    NASA Astrophysics Data System (ADS)

    Kimura, Akira

    In inverter-converter driving systems for AC electric cars, the DC input voltage of an inverter contains a ripple component with a frequency that is twice as high as the line voltage frequency, because of a single-phase converter. The ripple component of the inverter input voltage causes pulsations on torques and currents of driving motors. To decrease the pulsations, a beat-less control method, which modifies a slip frequency depending on the ripple component, is applied to the inverter control. In the present paper, the beat-less control method was analyzed in the frequency domain. In the first step of the analysis, transfer functions, which revealed the relationship among the ripple component of the inverter input voltage, the slip frequency, the motor torque pulsation and the current pulsation, were derived with a synchronous rotating model of induction motors. An analysis model of the beat-less control method was then constructed using the transfer functions. The optimal setting of the control method was obtained according to the analysis model. The transfer functions and the analysis model were verified through simulations.

  2. An automatic bridge for inductive voltage dividers

    SciTech Connect

    Chang, P.; Liang, C.P.; Hsiao, J.C.

    1994-12-31

    We describe an automatic, injection-type bridge for inductive voltage divider (IVD) applications at low audio frequencies. We used it to self-calibrate programmable IVDs fabricated in house, by an automated {open_quotes}boot-strap{close_quotes} procedure. It is the heart of our reference standard for ac voltage ratios as well as a calibration system for IVDs.

  3. Motor Controller

    NASA Technical Reports Server (NTRS)

    1988-01-01

    M.H. Marks Enterprises' Power Factor Controller (PFC) matches voltage with motor's actual need. Plugged into a motor, PFC continuously determines motor load by sensing shifts between voltage and current flow. When it senses a light load, it cuts voltage to the minimum needed. It offers potential energy savings ranging from eight percent up to 65 percent depending on the application. Myles Marks started out with the notion of writing an article for Popular Electronics magazine at the same time offering to furnish kits to readers interested in assembling PFC's. Within two weeks from publication he had orders for 500 kits and orders are still coming three years later.

  4. Stepper motor

    NASA Technical Reports Server (NTRS)

    Dekramer, Cornelis

    1994-01-01

    The purpose of this document is to describe the more commonly used permanent magnet stepper motors for spaceflight. It will discuss the mechanical and electrical aspects of the devices, their torque behavior, those parameters which need to be controlled and measured, and test methods to be employed. It will also discuss torque margins, compare these to the existing margin requirements, and determine the applicability of these requirements. Finally it will attempt to generate a set of requirements which will be used in any stepper motor procurement and will fully characterize the stepper motor behavior in a consistent and repeatable fashion.

  5. A Computer Model for Teaching the Dynamic Behavior of AC Contactors

    ERIC Educational Resources Information Center

    Ruiz, J.-R. R.; Espinosa, A. G.; Romeral, L.

    2010-01-01

    Ac-powered contactors are extensively used in industry in applications such as automatic electrical devices, motor starters, and heaters. In this work, a practical session that allows students to model and simulate the dynamic behavior of ac-powered electromechanical contactors is presented. Simulation is carried out using a rigorous parametric…

  6. Chaotic motors

    NASA Astrophysics Data System (ADS)

    Laroche, C.; Labbé, R.; Pétrélis, F.; Fauve, S.

    2012-02-01

    We show that electric motors and dynamos can be used to illustrate most elementary instabilities or bifurcations discussed in courses on nonlinear oscillators and dynamical systems. These examples are easier to understand and display a richer behavior than the ones commonly used from mechanics, electronics, hydrodynamics, lasers, chemical reactions, and population dynamics. In particular, an electric motor driven by a dynamo can display stationary, Hopf, and codimension-two bifurcations by tuning the driving speed of the dynamo and the electric current in the stator of the electric motor. When the dynamo is driven at constant torque instead of constant rotation rate, chaotic reversals of the generated current and of the angular rotation of the motor are observed. Simple deterministic models are presented which capture the observed dynamical regimes.

  7. 14. POWERHOUSE INTERIOR, EXCITER No. 2 SHOWING GENERAL ELECTRIC INDUCTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. POWERHOUSE INTERIOR, EXCITER No. 2 SHOWING GENERAL ELECTRIC INDUCTION MOTOR IN SERIES BETWEEN PELTON-DOBLE IMPULSE WHEEL AND GENERAL ELECTRIC GENERATOR. VIEW TO EAST. - Rush Creek Hydroelectric System, Powerhouse Exciters, Rush Creek, June Lake, Mono County, CA

  8. Method and apparatus for improved efficiency in a pulse-width-modulated alternating current motor drive

    DOEpatents

    Konrad, C.E.; Boothe, R.W.

    1996-01-23

    A scheme for optimizing the efficiency of an AC motor drive operated in a pulse-width-modulated mode provides that the modulation frequency of the power furnished to the motor is a function of commanded motor torque and is higher at lower torque requirements than at higher torque requirements. 6 figs.

  9. Method and apparatus for improved efficiency in a pulse-width-modulated alternating current motor drive

    DOEpatents

    Konrad, Charles E.; Boothe, Richard W.

    1994-01-01

    A scheme for optimizing the efficiency of an AC motor drive operated in a pulse-width-modulated mode provides that the modulation frequency of the power furnished to the motor is a function of commanded motor torque and is higher at lower torque requirements than at higher torque requirements.

  10. 21 CFR 878.4820 - Surgical instrument motors and accessories/attachments.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Surgical instrument motors and accessories....4820 Surgical instrument motors and accessories/attachments. (a) Identification. Surgical instrument motors and accessories are AC-powered, battery-powered, or air-powered devices intended for use...

  11. Method and apparatus for improved efficiency in a pulse-width-modulated alternating current motor drive

    DOEpatents

    Konrad, Charles E.; Boothe, Richard W.

    1996-01-01

    A scheme for optimizing the efficiency of an AC motor drive operated in a pulse-width-modulated mode provides that the modulation frequency of the power furnished to the motor is a function of commanded motor torque and is higher at lower torque requirements than at higher torque requirements.

  12. Method and apparatus for improved efficiency in a pulse-width-modulated alternating current motor drive

    DOEpatents

    Konrad, C.E.; Boothe, R.W.

    1994-02-15

    A scheme for optimizing the efficiency of an AC motor drive operated in a pulse-width-modulated mode provides that the modulation frequency of the power furnished to the motor is a function of commanded motor torque and is higher at lower torque requirements than at higher torque requirements. 6 figures.

  13. Microfabricated AC impedance sensor

    DOEpatents

    Krulevitch, Peter; Ackler, Harold D.; Becker, Frederick; Boser, Bernhard E.; Eldredge, Adam B.; Fuller, Christopher K.; Gascoyne, Peter R. C.; Hamilton, Julie K.; Swierkowski, Stefan P.; Wang, Xiao-Bo

    2002-01-01

    A microfabricated instrument for detecting and identifying cells and other particles based on alternating current (AC) impedance measurements. The microfabricated AC impedance sensor includes two critical elements: 1) a microfluidic chip, preferably of glass substrates, having at least one microchannel therein and with electrodes patterned on both substrates, and 2) electrical circuits that connect to the electrodes on the microfluidic chip and detect signals associated with particles traveling down the microchannels. These circuits enable multiple AC impedance measurements of individual particles at high throughput rates with sufficient resolution to identify different particle and cell types as appropriate for environmental detection and clinical diagnostic applications.

  14. Universal adaptive torque control for PM motors for field-weakening region operation

    DOEpatents

    Royak, Semyon; Harbaugh, Mark M.; Breitzmann, Robert J.; Nondahl, Thomas A.; Schmidt, Peter B.; Liu, Jingbo

    2011-03-29

    The invention includes a motor controller and method for controlling a permanent magnet motor. In accordance with one aspect of the present technique, a permanent magnet motor is controlled by, among other things, receiving a torque command, determining a normalized torque command by normalizing the torque command to a characteristic current of the motor, determining a normalized maximum available voltage, determining an inductance ratio of the motor, and determining a direct-axis current based upon the normalized torque command, the normalized maximum available voltage, and the inductance ratio of the motor.

  15. Advanced Motors

    SciTech Connect

    Knoth, Edward A; Chelluri, Bhanumathi; Schumaker, Edward J

    2012-12-14

    vProject Summary Transportation energy usage is predicted to increase substantially by 2020. Hybrid vehicles and fuel cell powered vehicles are destined to become more prominent as fuel prices rise with the demand. Hybrid and fuel cell vehicle platforms are both dependent on high performance electric motors. Electric motors for transportation duty will require sizeable low-speed torque to accelerate the vehicle. As motor speed increases, the torque requirement decreases which results in a nearly constant power motor output. Interior permanent magnet synchronous motors (IPMSM) are well suited for this duty. , , These rotor geometries are configured in straight lines and semi circular arc shapes. These designs are of limited configurations because of the lack of availability of permanent magnets of any other shapes at present. We propose to fabricate rotors via a novel processing approach where we start with magnet powders and compact them into a net shape rotor in a single step. Using this approach, widely different rotor designs can be implemented for efficiency. The current limitation on magnet shape and thickness will be eliminated. This is accomplished by co-filling magnet and soft iron powders at specified locations in intricate shapes using specially designed dies and automatic powder filling station. The process fundamentals for accomplishing occurred under a previous Applied Technology Program titled, Motors and Generators for the 21st Century. New efficient motor designs that are not currently possible (or cost prohibitive) can be accomplished by this approach. Such an approach to motor fabrication opens up a new dimension in motor design. Feasibility Results We were able to optimize a IPMSM rotor to take advantage of the powder co-filling and DMC compaction processing methods. The minimum low speed torque requirement of 5 N-m can be met through an optimized design with magnet material having a Br capability of 0.2 T. This level of magnetic performance can

  16. Motor Planning.

    PubMed

    Wong, Aaron L; Haith, Adrian M; Krakauer, John W

    2015-08-01

    Motor planning colloquially refers to any process related to the preparation of a movement that occurs during the reaction time prior to movement onset. However, this broad definition encompasses processes that are not strictly motor-related, such as decision-making about the identity of task-relevant stimuli in the environment. Furthermore, the assumption that all motor-planning processes require processing time, and can therefore be studied behaviorally by measuring changes in the reaction time, needs to be reexamined. In this review, we take a critical look at the processes leading from perception to action and suggest a definition of motor planning that encompasses only those processes necessary for a movement to be executed-that is, processes that are strictly movement related. These processes resolve the ambiguity inherent in an abstract goal by defining a specific movement to achieve it. We propose that the majority of processes that meet this definition can be completed nearly instantaneously, which means that motor planning itself in fact consumes only a small fraction of the reaction time. PMID:24981338

  17. Combined transcranial alternating current stimulation and continuous theta burst stimulation: a novel approach for neuroplasticity induction.

    PubMed

    Goldsworthy, Mitchell R; Vallence, Ann-Maree; Yang, Ruiting; Pitcher, Julia B; Ridding, Michael C

    2016-02-01

    Non-invasive brain stimulation can induce functionally relevant plasticity in the human cortex, making it potentially useful as a therapeutic tool. However, the induced changes are highly variable between individuals, potentially limiting research and clinical utility. One factor that might contribute to this variability is the level of cortical inhibition at the time of stimulation. The alpha rhythm (~ 8-13 Hz) recorded with electroencephalography (EEG) is thought to reflect pulsatile cortical inhibition; therefore, targeting non-invasive brain stimulation to particular phases of the alpha rhythm may provide an approach to enhance plasticity induction. Transcranial alternating current stimulation (tACS) has been shown to entrain cortical oscillations in a frequency-specific manner. We investigated whether the neuroplastic response to continuous theta burst stimulation (cTBS) was enhanced by timing bursts of stimuli to the peak or the trough of a tACS-imposed alpha rhythm. While motor evoked potentials (MEPs) were unaffected when cTBS was applied in-phase with the peak of the tACS-imposed oscillation, MEP depression was enhanced when cTBS was applied in-phase with the trough. This enhanced MEP depression was dependent on the individual peak frequency of the endogenous alpha rhythm recorded with EEG prior to stimulation, and was strongest in those participants classified as non-responders to standard cTBS. These findings suggest that tACS may be used in combination with cTBS to enhance the plasticity response. Furthermore, the peak frequency of endogenous alpha, as measured with EEG, may be used as a simple marker to pre-select those individuals likely to benefit from this approach. PMID:26663460

  18. Using the motor to monitor pump conditions

    SciTech Connect

    Casada, D.

    1996-12-01

    When the load of a mechanical device being driven by a motor changes, whether in response to changes in the overall process or changes in the performance of the driven device, the motor inherently responds. For induction motors, the current amplitude and phase angle change as the shaft load changes. By examining the details of these changes in amplitude and phase, load fluctuations of the driven device can be observed. The usefulness of the motor as a transducer to improve the understanding of devices with high torque fluctuations, such as positive displacement compressors and motor-operated valves, has been recognized and demonstrated for a number of years. On such devices as these, the spectrum of the motor current amplitude, phase, or power normally has certain characteristic peaks associated with various load components, such as the piston stroke or gear tooth meshing frequencies. Comparison and trending of the amplitudes of these peaks has been shown to provide some indication of their mechanical condition. For most centrifugal pumps, the load fluctuations are normally low in torque amplitude, and as a result, the motor experiences a correspondingly lower level of load fluctuation. However, both laboratory and field test data have demonstrated that the motor does provide insight into some important pump performance conditions, such as hydraulic stability and pump-to-motor alignment. Comparisons of other dynamic signals, such as vibration and pressure pulsation, to motor data for centrifugal pumps are provided. The effects of inadequate suction head, misalignment, mechanical and hydraulic unbalance on these signals are presented.

  19. AC magnetohydrodynamic microfluidic switch

    SciTech Connect

    Lemoff, A V; Lee, A P

    2000-03-02

    A microfluidic switch has been demonstrated using an AC Magnetohydrodynamic (MHD) pumping mechanism in which the Lorentz force is used to pump an electrolytic solution. By integrating two AC MHD pumps into different arms of a Y-shaped fluidic circuit, flow can be switched between the two arms. This type of switch can be used to produce complex fluidic routing, which may have multiple applications in {micro}TAS.

  20. ACS Symposium Support

    SciTech Connect

    Kenneth D. Jordan

    2010-02-20

    The funds from this DOE grant were used to help cover the travel costs of five students and postdoctoral fellows who attended a symposium on 'Hydration: From Clusters to Aqueous Solutions' held at the Fall 2007 American Chemical Society Meeting in Boston, MA, August 19-23. The Symposium was sponsored by the Physical Chemistry Division, ACS. The technical program for the meeting is available at http://phys-acs.org/fall2007.html.

  1. Induction squirrel cage machine design with minimization of electromagnetic noise

    SciTech Connect

    Hadj Amor, A.; Timar, P.L.; Poloujadoff, M.

    1995-12-01

    The noise created by an induction motor design, satisfying given specifications, is a function of eight independent variables. Its minimum value may be found by any unconstrained optimization technique. The minimum noise corresponds to a very expensive and heavy motor; therefore the conflict of interest must be dealt with. It is shown that the optimum design is independent of eccentricity.

  2. AC loss in superconducting tapes and cables

    NASA Astrophysics Data System (ADS)

    Oomen, Marijn Pieter

    High-temperature superconductors are developed for use in power-transmission cables, transformers and motors. The alternating magnetic field in these devices causes AC loss, which is a critical factor in the design. The study focuses on multi-filament Bi-2223/Ag tapes exposed to a 50-Hz magnetic field at 77 K. The AC loss is measured with magnetic, electric and calorimetric methods. The results are compared to theoretical predictions based mainly on the Critical-State Model. The loss in high- temperature superconductors is affected by their characteristic properties: increased flux creep, high aspect ratio and inhomogeneties. Filament intergrowths and a low matrix resistivity cause a high coupling-current loss especially when the filaments are fully coupled. When the wide side of the tape is parallel to the external magnetic field, the filaments are decoupled by twisting. In a perpendicular field the filaments can be decoupled only by combining a short twist pitch with a transverse resistivity much higher than that of silver. The arrangement of the inner filaments determines the transverse resistivity. Ceramic barriers around the filaments cause partial decoupling in perpendicular magnetic fields at power frequencies. The resultant decrease in AC loss is greater than the accompanying decrease in critical current. With direct transport current in alternating magnetic field, the transport-current loss is well described with a new model for the dynamic resistance. The Critical- State Model describes well the magnetisation and total AC loss in parallel magnetic fields, at transport currents up to 0.7 times the critical current. When tapes are stacked face-to-face in a winding, the AC-loss density in perpendicular fields is greatly decreased due to the mutual shielding of the tapes. Coupling currents between the tapes in a cable cause an extra AC loss, which is reduced by a careful cable design. The total AC loss in complex devices with many tapes is generally well

  3. Therma motor

    DOEpatents

    Kandarian, R.

    The disclosure is directed to a thermal motor utilizing two tapered prestressed parallel adjacent cylinders lengthwise disposed about one third in a coolant. Heat is applied to contacting portions of the cylinders outside the coolant to cause them to deform and turn. Heat sources such as industrial waste heat, geothermal hot water, solar radiation, etc. can be used.

  4. High-Frequency ac Power-Distribution System

    NASA Technical Reports Server (NTRS)

    Hansen, Irving G.; Mildice, James

    1987-01-01

    Loads managed automatically under cycle-by-cycle control. 440-V rms, 20-kHz ac power system developed. System flexible, versatile, and "transparent" to user equipment, while maintaining high efficiency and low weight. Electrical source, from dc to 2,200-Hz ac converted to 440-V rms, 20-kHz, single-phase ac. Power distributed through low-inductance cables. Output power either dc or variable ac. Energy transferred per cycle reduced by factor of 50. Number of parts reduced by factor of about 5 and power loss reduced by two-thirds. Factors result in increased reliability and reduced costs. Used in any power-distribution system requiring high efficiency, high reliability, low weight, and flexibility to handle variety of sources and loads.

  5. Motor Neuron Diseases

    MedlinePlus

    ... Enhancing Diversity Find People About NINDS NINDS Motor Neuron Diseases Information Page Condensed from Motor Neuron Diseases ... and Information Publicaciones en Español What are Motor Neuron Diseases? The motor neuron diseases (MNDs) are a ...

  6. Motor Neuron Diseases

    MedlinePlus

    ... called upper motor neurons ) are transmitted to nerve cells in the brain stem and spinal cord (called lower motor neurons ) and from them to particular muscles. Upper motor neurons direct the lower motor neurons ...

  7. Phase and Frequency-Dependent Effects of Transcranial Alternating Current Stimulation on Motor Cortical Excitability.

    PubMed

    Nakazono, Hisato; Ogata, Katsuya; Kuroda, Tsuyoshi; Tobimatsu, Shozo

    2016-01-01

    Transcranial alternating current stimulation (tACS) can entrain ongoing brain oscillations and modulate the motor system in a frequency-dependent manner. Recent animal studies have demonstrated that the phase of a sinusoidal current also has an important role in modulation of neuronal activity. However, the phase effects of tACS on the human motor system are largely unknown. Here, we systematically investigated the effects of tACS phase and frequency on the primary motor cortex (M1) by using motor evoked potentials (MEPs) with transcranial magnetic stimulation (TMS). First, we compared the phase effects (90°, 180°, 270° or 360°) of 10 and 20 Hz tACS on MEPs. The 20 Hz tACS significantly increased M1 excitability compared with the 10 Hz tACS at 90° phase only. Second, we studied the 90° phase effect on MEPs at different tACS frequencies (5, 10, 20 or 40 Hz). The 20 vs. 10 Hz difference was again observed, but the 90° phase in 5 and 40 Hz tACS did not influence M1 excitability. Third, the 90° phase effects of 10 and 20 Hz tACS were compared with sham stimulation. The 90° phase of 20 Hz tACS enhanced MEP amplitudes compared with sham stimulation, but there was no significant effect of 10 Hz tACS. Taken together, we assume that the differential 90° phase effects on 20 Hz and 10 Hz tACS can be attributed to the neural synchronization modulated by tACS. Our results further underline that phase and frequency are the important factors in the effects of tACS on M1 excitability. PMID:27607431

  8. Pump for spawning channels includes a turbine and motor. Turbine ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Pump for spawning channels includes a turbine and motor. Turbine is Berkeley H-17500, model 8C2PH, Serial No. 2889, B.M. No. 4886 - Berkeley Pump Co. The Motor is G.E. Induction Motor, model 5K4256XA3YI, serial no. GAJ728337, Tri-Clad. View looking northeast. - Prairie Creek Fish Hatchery, Hwy. 101, Orick, Humboldt County, CA

  9. Transient model of a doubly excited reluctance motor

    SciTech Connect

    Xu, L.; Liang, F.; Lipo, T.A. . Dept. of Electrical and Computer Engineering)

    1991-03-01

    A transient machine model of a doubly fed reluctance motor is derived by means of winding function and d-q transformation theory. The machine consists of a double wound stator having four and eight pole sets. The rotor is equipped with six poles. The machine, related to the Hunt motor, has a synchronous speed of a twelve pole machine. Comparison of simulated to tested results indicates that the higher harmonics in the motor inductances are important for predicting current waveform.

  10. Tevatron AC dipole system

    SciTech Connect

    Miyamoto, R.; Kopp, S.E.; Jansson, A.; Syphers, M.J.; /Fermilab

    2007-06-01

    The AC dipole is an oscillating dipole magnet which can induce large amplitude oscillations without the emittance growth and decoherence. These properties make it a good tool to measure optics of a hadron synchrotron. The vertical AC dipole for the Tevatron is powered by an inexpensive high power audio amplifier since its operating frequency is approximately 20 kHz. The magnet is incorporated into a parallel resonant system to maximize the current. The use of a vertical pinger magnet which has been installed in the Tevatron made the cost relatively inexpensive. Recently, the initial system was upgraded with a more powerful amplifier and oscillation amplitudes up to 2-3{sigma} were achieved with the 980 GeV proton beam. This paper discusses details of the Tevatron AC dipole system and also shows its test results.

  11. Optimization of Magnet Arrangement in Double-Layer Interior Permanent-Magnet Motors

    NASA Astrophysics Data System (ADS)

    Yamazaki, Katsumi; Kitayuguchi, Kazuya

    The arrangement of permanent magnets in double-layer interior permanent-magnet motors is optimized for variable-speed applications. First, the arrangement of magnets is decided by automatic optimization. Next, the superiority of the optimized motor is discussed by the d- and q-axis equivalent circuits that consider the magnetic saturation of the rotor core. Finally, experimental verification is carried out by using a prototype motor. It is confirmed that the maximum torque of the optimized motor under both low speed and high speed conditions are higher than those of conventional motors because of relatively large q-axis inductance and small d-axis inductance.

  12. Early augmented language intervention for children with developmental delays: potential secondary motor outcomes.

    PubMed

    Whitmore, Ani S; Romski, Mary Ann; Sevcik, Rose A

    2014-09-01

    This exploratory study examined the potential secondary outcome of an early augmented language intervention that incorporates speech-generating devices (SGD) on motor skill use for children with developmental delays. The data presented are from a longitudinal study by Romski and colleagues. Toddlers in the augmented language interventions were either required (Augmented Communication-Output; AC-O) or not required (Augmented Communication-Input; AC-I) to use the SGD to produce an augmented word. Three standardized assessments and five event-based coding schemes measured the participants' language abilities and motor skills. Toddlers in the AC-O intervention used more developmentally appropriate motor movements and became more accurate when using the SGD to communicate than toddlers in the AC-I intervention. AAC strategies, interventionist/parent support, motor learning opportunities, and physical feedback may all contribute to this secondary benefit of AAC interventions that use devices. PMID:25109299

  13. AC/RF Superconductivity

    SciTech Connect

    Ciovati, Gianluigi

    2015-02-01

    This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field dependence of the surface resistance, and the superheating field.

  14. AC solar cell

    SciTech Connect

    Schutten, H.P.; Benjamin, J.A.; Lade, R.W.

    1986-03-18

    An AC solar cell is described comprising: a pair of PN junction type solar cells connected in antiparallel between a pair of main terminals; and means for electrically directing light alternatingly without mechanical movement on the PN junctions to generate an alternating potential across the main terminals.

  15. AC 67 Launch Video

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Live footage of the Unmanned Atlas Centaur (AC) 67 launch is presented on March 26, 1987 at the WESH television station in Florida. Lightning is shown after 49 seconds into the flight. The vehicle is totally destroyed due to a cloud-to-ground lightning flash.

  16. Fast or Slow, Either Head Can Start the Processive Run of Kinesin-2 KIF3AC.

    PubMed

    Zhang, Pengwei; Rayment, Ivan; Gilbert, Susan P

    2016-02-26

    Mammalian KIF3AC contains two distinct motor polypeptides and is best known for its role in organelle transport in neurons. Our recent studies showed that KIF3AC is as processive as conventional kinesin-1, suggesting that their ATPase mechanochemistry may be similar. However, the presence of two different motor polypeptides in KIF3AC implies that there must be a cellular advantage for the KIF3AC heterodimer. The hypothesis tested was whether there is an intrinsic bias within KIF3AC such that either KIF3A or KIF3C initiates the processive run. To pursue these experiments, a mechanistic approach was used to compare the pre-steady-state kinetics of KIF3AC to the kinetics of homodimeric KIF3AA and KIF3CC. The results indicate that microtubule collision at 11.4 μm(-1) s(-1) coupled with ADP release at 78 s(-1) are fast steps for homodimeric KIF3AA. In contrast, KIF3CC exhibits much slower microtubule association at 2.1 μm(-1) s(-1) and ADP release at 8 s(-1). For KIF3AC, microtubule association at 6.6 μm(-1) s(-1) and ADP release at 51 s(-1) are intermediate between the constants for KIF3AA and KIF3CC. These results indicate that either KIF3A or KIF3C can initiate the processive run. Surprisingly, the kinetics of the initial event of microtubule collision followed by ADP release for KIF3AC is not equivalent to 1:1 mixtures of KIF3AA plus KIF3CC homodimers at the same motor concentration. These results reveal that the intermolecular communication within the KIF3AC heterodimer modulates entry into the processive run regardless of whether the run is initiated by the KIF3A or KIF3C motor domain. PMID:26710851

  17. Piezoelectric/magnetostrictive resonant inchworm motor

    NASA Astrophysics Data System (ADS)

    Miesner, John E.; Teter, Joseph P.

    1994-05-01

    Magnetostrictive and piezoelectric materials were used to create a linear motor operating on the inchworm principle. This motor operates at an electrical resonance, switching power internally between inductive and capacitive components. Magnetic coils surrounding the two Terfenol-D rods which drive the inchworm's center expanding element form the inductive component. Piezoelectric stacks that control the end clamping action are the capacitive components. The normal electrical phase relationship between these components provides natural drive timing for the inchworm. The motor direction can be easily reversed by changing the magnetic bias on the Terfenol. A prototype motor was built that achieved a stall load of 26 lb and no-load speed of 1 inch/sec vs the design of 30 lb and 1.3 inch/sec. A new type of power supply that switches power from a dc source was built for the motor. This power supply uses a small number of components to exactly supply the energy used in each inchworm cycle. It tracks the motor circuit resonance and is not affected by frequency shifts.

  18. Energy-efficient steels for motor laminations

    NASA Astrophysics Data System (ADS)

    Werner, F. E.; Jaffee, R. I.

    1992-03-01

    Motors use over 60% of all electricity generated, and their losses exceed 200 × 109 kW.hr/year. A significant part of this loss results from eddy currents and hysteretic processes in the motor laminations. These so- called core losses cost motor users about 3 × 109/year. The metallurgy and economics of using various steels are considered, with emphasis on 5- to 125- hp polyphase induction motors. A lower core loss steel, even though it is more expensive, is economically justified most of the time when the operating costs of motors are considered. Impurities must be minimized, and steels can now be made with the principal impurities being less than 30 ppm. Further reduction of core losses depends on using the best steel processing equipment available, production of a consistently low carbon content so that decarburizing during the final anneal can be eliminated, developing a better understanding of the relation between material properties and performance in motors, and an increased willingness by the motor users to pay more for better motors that are cheaper to own in the long run.

  19. Efficiency optimal control for AC drives with PWM inverters

    SciTech Connect

    Zach, F.C.; Ertl, H.

    1985-07-01

    For electrical drives using pulsewidth modulation (PWM) inverters and ac motors, methods for efficiency optimal control (EOC) have been developed. They are based on the most complete motor models, including such features as rotor skin effect. Furthermore, new solutions for selected harmonic elimination (SHE) are given. These new solutions come close to EOC. Also, it has been found that EOC solutions (although basically load-dependent as opposed to SHE) do not vary much with the motor used or the motor model applied. Even using a simple R-L series circuit as motor model does not change the solutions much. It is found that using the solutions gained from such a simple model is not more than two points off the real optimum based on a very complete motor model. (For this definition, the absolute harmonic loss minimum is given as zero points, the overall maximum as 100 points with a linear scale in between.) Therefore, one can use one EOC solution for all motors with sufficient accuracy, or, as second best solution, the new form of SHE. Therefore, the EOC solution can be judged load-independent. The implementation by microprocessor-based systems is as easy for other PWM methods. EOC for three and five switching angles per quarter period is discussed, as well as the new solutions for SHE for up to nine angles.

  20. Equivalent Electrical Circuit Representations of AC Quantized Hall Resistance Standards

    PubMed Central

    Cage, M. E.; Jeffery, A.; Matthews, J.

    1999-01-01

    We use equivalent electrical circuits to analyze the effects of large parasitic impedances existing in all sample probes on four-terminal-pair measurements of the ac quantized Hall resistance RH. The circuit components include the externally measurable parasitic capacitances, inductances, lead resistances, and leakage resistances of ac quantized Hall resistance standards, as well as components that represent the electrical characteristics of the quantum Hall effect device (QHE). Two kinds of electrical circuit connections to the QHE are described and considered: single-series “offset” and quadruple-series. (We eliminated other connections in earlier analyses because they did not provide the desired accuracy with all sample probe leads attached at the device.) Exact, but complicated, algebraic equations are derived for the currents and measured quantized Hall voltages for these two circuits. Only the quadruple-series connection circuit meets our desired goal of measuring RH for both ac and dc currents with a one-standard-deviation uncertainty of 10−8 RH or less during the same cool-down with all leads attached at the device. The single-series “offset” connection circuit meets our other desired goal of also measuring the longitudinal resistance Rx for both ac and dc currents during that same cool-down. We will use these predictions to apply small measurable corrections, and uncertainties of the corrections, to ac measurements of RH in order to realize an intrinsic ac quantized Hall resistance standard of 10−8 RH uncertainty or less.

  1. Disc Motor: Conventional and Superconductor Simulated Results Analysis

    NASA Astrophysics Data System (ADS)

    Inácio, David; Martins, João; Neves, Mário Ventim; Álvarez, Alfredo; Rodrigues, Amadeu Leão

    Taking into consideration the development and integration of electrical machines with lower dimensions and higher performance, this paper presents the design and development of a three-phase axial flux disc motor, with 50 Hz frequency supply. It is made with two conventional semi-stators and a rotor, which can be implemented with a conventional aluminum disc or a high temperature-superconducting disc. The analysis of the motor characteristics is done with a 2D commercial finite elements package, being the modeling performed as a linear motor. The obtained results allow concluding that the superconductor motor provides a higher force than the conventional one. The conventional disc motor presents an asynchronous behavior, like a conventional induction motor, while the superconductor motor presents both synchronous and asynchronous behaviors.

  2. AC power systems handbook

    SciTech Connect

    Whitaker, J.

    1991-01-01

    Transient disturbances are what headaches are made of. Whatever you call them-spikes, surges, are power bumps-they can take your equipment down and leave you with a complicated and expensive repair job. Protection against transient disturbances is a science that demands attention to detail. This book explains how the power distribution system works, what can go wrong with it, and how to protect a facility against abnormalities. system grounding and shielding are covered in detail. Each major method of transient protection is analyzed and its relative merits discussed. The book provides a complete look at the critical elements of the ac power system. Provides a complete look at the ac power system from generation to consumption. Discusses the mechanisms that produce transient disturbances and how to protect against them. Presents diagrams to facilitate system design. Covers new areas, such as the extent of the transient disturbance problem, transient protection options, and stand-by power systems.

  3. Gross motor control

    MedlinePlus

    Gross motor control is the ability to make large, general movements (such as waving an arm or lifting a ... Gross motor control is a milestone in the development of an infant. Infants develop gross motor control before they ...

  4. Multifocal Motor Neuropathy

    MedlinePlus

    ... Diversity Find People About NINDS NINDS Multifocal Motor Neuropathy Information Page Table of Contents (click to jump ... done? Clinical Trials Organizations What is Multifocal Motor Neuropathy? Multifocal motor neuropathy is a progressive muscle disorder ...

  5. Computer aided design of multi-phase switched reluctance motor

    NASA Astrophysics Data System (ADS)

    Sheth, N. K.; Rajagopal, K. R.

    2005-05-01

    In this paper, a comprehensive computer-aided design (CAD) procedure of multiphase switched reluctance motor (SRM) is presented. Better approach for calculation of the outer dimensions, phase inductance, flux linkage and losses, and also a different concept for calculating the average torque of the motor are incorporated in the CAD program. The average torque is calculated based on the most effective 15° (for 8/6 SRM) of the static torque profile of the motor. A sample design of a 5hp SRM is presented in detail and the design is validated by conducting a two-dimensional finite element analysis of the motor.

  6. Advanced electric motor technology flux mapping

    NASA Technical Reports Server (NTRS)

    Doane, George B., III; Campbell, Warren; Dean, Garvin

    1993-01-01

    Design of electric motors which fulfill the needs of Thrust Vector Control (TVC) actuators used in large rocket propelled launch vehicles is covered. To accomplish this end the methodology of design is laid out in some detail. In addition a point design of a motor to fulfill the requirements of a certain actuator specified by MSFC is accomplished and reported upon. In the course of this design great stress has been placed on ridding the actuator of internally generated heat. To conduct the heat out of the motor use is made of the unique properties of the in house MSFC designed driving electronics. This property is that as along as they are operated in a quasi-linear mode the electronics nullify the effects of armature inductance as far as the phase of the armature current versus the rotor position is concerned. Actually the additional inductance due to the extended end turns in this design is of benefit because in the shorted armature failure mode the armature current in the fault (caused by the rotor flux sweeping past the armature) is diminished at a given rotor speed when compared to a more conventional motor with lower inductance. The magnetic circuit is analyzed using electromagnetic finite element methods.

  7. Design and Control Implementation of AC Electric Power Steering System Test Bench*

    NASA Astrophysics Data System (ADS)

    Zhang, Weidong; Ai, Yibo

    Using AC motor is an important development trend of electric power steering system, and in this paper, we proposed a design of AC electric power steering system test bench. The paper introduced the bench structure, working principle and main components selection first, and then given the implementation scheme of test bench's three functions: simulation of the road resistance, power assistant control and data acquisition. The test results showed the feasibility of the test bench.

  8. Motor control for a brushless DC motor

    NASA Technical Reports Server (NTRS)

    Peterson, William J. (Inventor); Faulkner, Dennis T. (Inventor)

    1985-01-01

    This invention relates to a motor control system for a brushless DC motor having an inverter responsively coupled to the motor control system and in power transmitting relationship to the motor. The motor control system includes a motor rotor speed detecting unit that provides a pulsed waveform signal proportional to rotor speed. This pulsed waveform signal is delivered to the inverter to thereby cause an inverter fundamental current waveform output to the motor to be switched at a rate proportional to said rotor speed. In addition, the fundamental current waveform is also pulse width modulated at a rate proportional to the rotor speed. A fundamental current waveform phase advance circuit is controllingly coupled to the inverter. The phase advance circuit is coupled to receive the pulsed waveform signal from the motor rotor speed detecting unit and phase advance the pulsed waveform signal as a predetermined function of motor speed to thereby cause the fundamental current waveform to be advanced and thereby compensate for fundamental current waveform lag due to motor winding reactance which allows the motor to operate at higher speeds than the motor is rated while providing optimal torque and therefore increased efficiency.

  9. The effect of 10 Hz transcranial alternating current stimulation (tACS) on corticomuscular coherence

    PubMed Central

    Wach, Claudia; Krause, Vanessa; Moliadze, Vera; Paulus, Walter; Schnitzler, Alfons; Pollok, Bettina

    2013-01-01

    Synchronous oscillatory activity at alpha (8–12 Hz), beta (13–30 Hz), and gamma (30–90 Hz) frequencies is assumed to play a key role for motor control. Corticomuscular coherence (CMC) represents an established measure of the pyramidal system's integrity. Transcranial alternating current stimulation (tACS) offers the possibility to modulate ongoing oscillatory activity. Behaviorally, 20 Hz tACS in healthy subjects has been shown to result in movement slowing. However, the neurophysiological changes underlying these effects are not entirely understood yet. The present study aimed at ascertaining the effects of tACS at 10 and 20 Hz in healthy subjects on CMC and local power of the primary sensorimotor cortex. Neuromagnetic activity was recorded during isometric contraction before and at two time points (2–10 min and 30–38 min) after tACS of the left primary motor cortex (M1), using a 306 channel whole head magnetoencephalography (MEG) system. Additionally, electromyography (EMG) of the right extensor digitorum communis (EDC) muscle was measured. TACS was applied at 10 and 20 Hz, respectively, for 10 min at 1 mA. Sham stimulation served as control condition. The data suggest that 10 Hz tACS significantly reduced low gamma band CMC during isometric contraction. This implies that tACS does not necessarily cause effects at stimulation frequency. Rather, the findings suggest cross-frequency interplay between alpha and low gamma band activity modulating functional interaction between motor cortex and muscle. PMID:24009573

  10. Multi-elemental characterization of tunnel and road dusts in Houston, Texas using dynamic reaction cell-quadrupole-inductively coupled plasma-mass spectrometry: evidence for the release of platinum group and anthropogenic metals from motor vehicles.

    PubMed

    Spada, Nicholas; Bozlaker, Ayse; Chellam, Shankararaman

    2012-07-20

    Platinum group elements (PGEs) including Rh, Pd, and Pt are important tracers for vehicular emissions, though their measurement is often challenging and difficult to replicate in environmental campaigns. These challenges arise from sample preparation steps required for PGE quantitation, which often cause severe isobaric interferences and spectral overlaps from polyatomic species of other anthropogenically emitted metals. Consequently, most previous road dust studies have either only quantified PGEs or included a small number of anthropogenic elements. Therefore a novel analytical method was developed to simultaneously measure PGEs, lanthanoids, transition and main group elements to comprehensively characterize the elemental composition of urban road and tunnel dusts. Dust samples collected from the vicinity of high-traffic roadways and a busy underwater tunnel restricted to single-axle (predominantly gasoline-driven) vehicles in Houston, TX were analyzed for 45 metals with the newly developed method using dynamic reaction cell-quadrupole-inductively coupled plasma-mass spectrometry (DRC-q-ICP-MS). Average Rh, Pd and Pt concentrations were 152±52, 770±208 and 529±130 ng g(-1) respectively in tunnel dusts while they varied between 6 and 8 ng g(-1), 10 and 88 ng g(-1) and 35 and 131 ng g(-1) in surface road dusts. Elemental ratios and enrichment factors demonstrated that PGEs in dusts originated from autocatalyst attrition/abrasion. Strong evidence is also presented for mobile source emissions of Cu, Zn, Ga, As, Mo, Cd, Sn, Sb, Ba, W and Pb. However, all other elements including rare earths most likely arose from weathering, erosion and resuspension of crustal material. These are the first such detailed measurements in Houston, the largest city in TX and fourth largest in the United States. We posit that such investigations will assist in better understanding PGE concentrations in urban environments while providing elemental data necessary to better understand

  11. A novel high power density permanent magnet variable-speed motor

    SciTech Connect

    Chan, C.C.; Chen, G.H.; Jiang, J.Z.; Wang, X.Y. )

    1993-06-01

    This paper proposes a novel polyphase multipole permanent magnet motor which possesses high power density, high efficiency and excellent controllability, yet can be produced by conventional fabrication technique. The basic operating principles, design features, performance analysis and control system are described. The experimental results of a 5 kW, 1,500 rpm prototype motor and its comparison with other types of motors such as switched reluctance motor and induction motor are given. This proposed motor has the potential to compete in certain applications.

  12. Calculating AC Losses in High-temperature Superconducting Cables Comprising Coated Conductors

    NASA Astrophysics Data System (ADS)

    Noji, Hideki; Kawano, Shouta; Akaki, Yoji; Hamada, Tsugio

    In this study, we present a new calculation model of AC loss in a high-temperature superconducting (HTS) cable comprising coated conductors. AC loss is calculated by an electric circuit (EC) model. A previous EC model had three circuit elements: resistance as a function of the layer current, inductances related to the circumferential and axial fields. The new EC model has only inductances, and resistance is eliminated. In both models, AC loss of the coated conductor in each layer of an HTS cable is calculated on the basis of the Norris equation for a thin strip. The differences between measurement and calculations using the previous and new models are 12% and 14%, respectively, when transporting 1 kArms, which indicates that the new model is applicable for the calculation of AC loss in an HTS cable. These results indicate that layer current is dependent on inductances and not on resistance. The elimination of resistance simplifies AC loss calculation because it does not require repeated calculations for the convergence of the layer current. The calculation time was 1/20th of that of the previous model. In the new model, the Norris equation can be replaced with the calculation result obtained by the two-dimensional finite element method to obtain more accurate AC loss.

  13. Identification of /sup 233/Ac

    SciTech Connect

    Chu, Y.Y.; Zhou, M.L.

    1983-09-01

    We report in this paper identification of the new isotope /sup 233/Ac. Uranium targets were irradiated with 28 GeV protons; after rapid retrieval of the target and separation of actinium from thorium, /sup 233/Ac was allowed to decay into the known /sup 233/Th daughter. Exhaustive chemical purification was employed to permit the identification of /sup 233/Th via its characteristic ..gamma.. radiations. The half-life derived for /sup 233/Ac from several experiments is 2.3 +- 0.3 min. The production cross section for /sup 233/Ac is 100 ..mu..b.

  14. AC resistance measuring instrument

    DOEpatents

    Hof, P.J.

    1983-10-04

    An auto-ranging AC resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an AC excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance. After the auto-ranging and auto-compensation functions are complete, the microprocessor calculates the resistance of the load from the selected range resistance, the excitation signal, and the load voltage signal, and displays of the measured resistance on a digital display of the instrument. 8 figs.

  15. AC Resistance measuring instrument

    DOEpatents

    Hof, Peter J.

    1983-01-01

    An auto-ranging AC resistance measuring instrument for remote measurement of the resistance of an electrical device or circuit connected to the instrument includes a signal generator which generates an AC excitation signal for application to a load, including the device and the transmission line, a monitoring circuit which provides a digitally encoded signal representing the voltage across the load, and a microprocessor which operates under program control to provide an auto-ranging function by which range resistance is connected in circuit with the load to limit the load voltage to an acceptable range for the instrument, and an auto-compensating function by which compensating capacitance is connected in shunt with the range resistance to compensate for the effects of line capacitance. After the auto-ranging and auto-compensation functions are complete, the microprocessor calculates the resistance of the load from the selected range resistance, the excitation signal, and the load voltage signal, and displays of the measured resistance on a digital display of the instrument.

  16. Electric Machine with Boosted Inductance to Stabilize Current Control

    NASA Technical Reports Server (NTRS)

    Abel, Steve

    2013-01-01

    High-powered motors typically have very low resistance and inductance (R and L) in their windings. This makes the pulse-width modulated (PWM) control of the current very difficult, especially when the bus voltage (V) is high. These R and L values are dictated by the motor size, torque (Kt), and back-emf (Kb) constants. These constants are in turn set by the voltage and the actuation torque-speed requirements. This problem is often addressed by placing inductive chokes within the controller. This approach is undesirable in that space is taken and heat is added to the controller. By keeping the same motor frame, reducing the wire size, and placing a correspondingly larger number of turns in each slot, the resistance, inductance, torque constant, and back-emf constant are all increased. The increased inductance aids the current control but ruins the Kt and Kb selections. If, however, a fraction of the turns is moved from their "correct slot" to an "incorrect slot," the increased R and L values are retained, but the Kt and Kb values are restored to the desired values. This approach assumes that increased resistance is acceptable to a degree. In effect, the heat allocated to the added inductance has been moved from the controller to the motor body, which in some cases is preferred.

  17. Losses in chopper-controlled DC series motors

    NASA Technical Reports Server (NTRS)

    Hamilton, H. B.

    1982-01-01

    Motors for electric vehicle (EV) applications must have different features than dc motors designed for industrial applications. The EV motor application is characterized by the following requirements: (1) the need for highest possible efficiency from light load to overload, for maximum EV range, (2) large short time overload capability (The ratio of peak to average power varies from 5/1 in heavy city traffic to 3/1 in suburban driving situations) and (3) operation from power supply voltage levels of 84 to 144 volts (probably 120 volts maximum). A test facility utilizing a dc generator as a substitute for a battery pack was designed and utilized. Criteria for the design of such a facility are presented. Two motors, differing in design detail, commercially available for EV use were tested. Losses measured are discussed, as are waves forms and their harmonic content, the measurements of resistance and inductance, EV motor/chopper application criteria, and motor design considerations.

  18. Losses in chopper-controlled DC series motors

    NASA Astrophysics Data System (ADS)

    Hamilton, H. B.

    1982-04-01

    Motors for electric vehicle (EV) applications must have different features than dc motors designed for industrial applications. The EV motor application is characterized by the following requirements: (1) the need for highest possible efficiency from light load to overload, for maximum EV range, (2) large short time overload capability (The ratio of peak to average power varies from 5/1 in heavy city traffic to 3/1 in suburban driving situations) and (3) operation from power supply voltage levels of 84 to 144 volts (probably 120 volts maximum). A test facility utilizing a dc generator as a substitute for a battery pack was designed and utilized. Criteria for the design of such a facility are presented. Two motors, differing in design detail, commercially available for EV use were tested. Losses measured are discussed, as are waves forms and their harmonic content, the measurements of resistance and inductance, EV motor/chopper application criteria, and motor design considerations.

  19. Variable-frequency synchronous motor drives for electric vehicles

    SciTech Connect

    Chalmers, B.J.; Musaba, L.; Gosden, D.F.

    1995-12-31

    The performance capability envelope of a variable-frequency, permanent-magnet synchronous motor drive with field weakening is dependent upon the product of maximum current and direct-axis inductance. To obtain a performance characteristic suitable for a typical electric vehicle drive, in which short-term increase of current is applied, it is necessary to design an optimum value of direct-axis inductance. The paper presents an analysis of a hybrid motor design which uses a two-part rotor construction comprising a surface-magnet part and an axially-laminated reluctance part. This arrangement combines the properties of all other types of synchronous motor and offers a greater choice of design variables. It is shown that the desired form of performance may be achieved when the high-inductance axis of the reluctance part is arranged to lead the magnet axis by 90{degree} (elec.).

  20. Variable-frequency synchronous motor drives for electric vehicles

    SciTech Connect

    Chalmers, B.J.; Musaba, L.; Gosden, D.F.

    1996-07-01

    The performance capability envelope of a variable-frequency, permanent-magnet synchronous motor drive with field weakening is dependent upon the product of maximum current and direct-axis inductance. To obtain a performance characteristic suitable for a typical electric vehicle drive, in which short-term increase of current is applied, it is necessary to design an optimum value of direct-axis inductance. The paper presents an analysis of a hybrid motor design which uses a two-part rotor construction comprising a surface-magnet part and an axially laminated reluctance part. This arrangement combines the properties of all other types of synchronous motor and offers a greater choice of design variables. It is shown that the desired form of performance may be achieved when the high-inductance axis of the reluctance part is arranged to lead the magnet axis by 90{degree} (elec.).

  1. Method for On-line Estimation of Electrical Motor Parameter Variation and Current Sensor Offset for SPM Motor

    NASA Astrophysics Data System (ADS)

    Uenaka, Yutaro; Sazawa, Masaki; Ohishi, Kiyoshi; Kenji, Takahashi

    The servo system of a permanent magnet (PM) motor should always maintain fine torque and fine speed responses. Accurate motor parameter identification is necessary for the PM motor servo system because the current control system is designed by considering the electric parameters of the PM motor. However, the motor parameters vary with the age of the motor and temperature. Moreover, current sensors have offset values. When the current sensor has offset values, the PM motor servo system produces torque ripple. In order to overcome these problems, this paper proposes a new real-time estimation method for both current sensor offsets and electrical parameters (resistance Ra, inductance La, and magnetic flux φfa) of the surface permanent magnet (SPM) motor. The proposed method involves the use of a real-time algorithm and a current simulator, which is operated using a DSP software system. In order to accurately estimate the motor parametera, the proposed method is using estimate currents, DC terms of sensor currents, and nominal motor parameter value. The experimental results of this study confirm that the proposed method satisfactorily estimates the current sensor offset of the U phase and V phase, as well as the electrical motor parametersRa, La, and φfa accurately.

  2. Induction generator produces constant-frequency voltage from variable-speed drive

    NASA Technical Reports Server (NTRS)

    Riaz, M.

    1970-01-01

    Two-stage polyphase generator is usable as induction motor operable over range of speeds while powered from constant frequency source. It requires neither slip rings nor special adjustable-frequency power supplies or external reactive sources.

  3. Imaging by electromagnetic induction with resonant circuits

    NASA Astrophysics Data System (ADS)

    Guilizzoni, Roberta; Watson, Joseph C.; Bartlett, Paul; Renzoni, Ferruccio

    2015-05-01

    A new electromagnetic induction imaging system is presented which is capable of imaging metallic samples of different conductivities. The system is based on a parallel LCR circuit made up of a cylindrical ferrite-cored coil and a capacitor bank. An AC current is applied to the coil, thus generating an AC magnetic field. This field is modified when a conductive sample is placed within the magnetic field, as a consequence of eddy current induction inside the sample. The electrical properties of the LCR circuit, including the coil inductance, are modified due to the presence of this metallic sample. Position-resolved measurements of these modifications should then allow imaging of conductive objects as well as enable their characterization. A proof-of-principle system is presented in this paper. Two imaging techniques based on Q-factor and resonant frequency measurements are presented. Both techniques produced conductivity maps of 14 metallic objects with different geometries and values of conductivity ranging from 0.54х106 to 59.77х106 S/m. Experimental results highlighted a higher sensitivity for the Q-factor technique compared to the resonant frequency one; the respective measurements were found to vary within the following ranges: ΔQ=[-11,-2]%, Δf=[-0.3,0.7]%. The analysis of the images, conducted using a Canny edge detection algorithm, demonstrated the suitability of the Q-factor technique for accurate edge detection of both magnetic and non-magnetic metallic samples.

  4. Cadmium-induced ethylene production and responses in Arabidopsis thaliana rely on ACS2 and ACS6 gene expression

    PubMed Central

    2014-01-01

    Background Anthropogenic activities cause metal pollution worldwide. Plants can absorb and accumulate these metals through their root system, inducing stress as a result of excess metal concentrations inside the plant. Ethylene is a regulator of multiple plant processes, and is affected by many biotic and abiotic stresses. Increased ethylene levels have been observed after exposure to excess metals but it remains unclear how the increased ethylene levels are achieved at the molecular level. In this study, the effects of cadmium (Cd) exposure on the production of ethylene and its precursor 1-aminocyclopropane-1-carboxylic acid (ACC), and on the expression of the ACC Synthase (ACS) and ACC Oxidase (ACO) multigene families were investigated in Arabidopsis thaliana. Results Increased ethylene release after Cd exposure was directly measurable in a system using rockwool-cultivated plants; enhanced levels of the ethylene precursor ACC together with higher mRNA levels of ethylene responsive genes: ACO2, ETR2 and ERF1 also indicated increased ethylene production in hydroponic culture. Regarding underlying mechanisms, it was found that the transcript levels of ACO2 and ACO4, the most abundantly expressed members of the ACO multigene family, were increased upon Cd exposure. ACC synthesis is the rate-limiting step in ethylene biosynthesis, and transcript levels of both ACS2 and ACS6 showed the highest increase and became the most abundant isoforms after Cd exposure, suggesting their importance in the Cd-induced increase of ethylene production. Conclusions Cadmium induced the biosynthesis of ACC and ethylene in Arabidopsis thaliana plants mainly via the increased expression of ACS2 and ACS6. This was confirmed in the acs2-1acs6-1 double knockout mutants, which showed a decreased ethylene production, positively affecting leaf biomass and resulting in a delayed induction of ethylene responsive gene expressions without significant differences in Cd contents between wild-type and

  5. Electromagnetic induction methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Electromagnetic induction geophysical methods are finding greater and greater use for agricultural purposes. Electromagnetic induction methods measure the electrical conductivity (or resistivity) for a bulk volume of soil directly beneath the surface. An instrument called a ground conductivity meter...

  6. Cooling Floor AC Systems

    NASA Astrophysics Data System (ADS)

    Jun, Lu; Hao, Ding; Hong, Zhang; Ce, Gao Dian

    The present HVAC equipments for the residential buildings in the Hot-summer-and-Cold-winter climate region are still at a high energy consuming level. So that the high efficiency HVAC system is an urgently need for achieving the preset government energy saving goal. With its advantage of highly sanitary, highly comfortable and uniform of temperature field, the hot-water resource floor radiation heating system has been widely accepted. This paper has put forward a new way in air-conditioning, which combines the fresh-air supply unit and such floor radiation system for the dehumidification and cooling in summer or heating in winter. By analyze its advantages and limitations, we found that this so called Cooling/ Heating Floor AC System can improve the IAQ of residential building while keep high efficiency quality. We also recommend a methodology for the HVAC system designing, which will ensure the reduction of energy cost of users.

  7. Digital ac monitor

    DOEpatents

    Hart, George W.; Kern, Jr., Edward C.

    1987-06-09

    An apparatus and method is provided for monitoring a plurality of analog ac circuits by sampling the voltage and current waveform in each circuit at predetermined intervals, converting the analog current and voltage samples to digital format, storing the digitized current and voltage samples and using the stored digitized current and voltage samples to calculate a variety of electrical parameters; some of which are derived from the stored samples. The non-derived quantities are repeatedly calculated and stored over many separate cycles then averaged. The derived quantities are then calculated at the end of an averaging period. This produces a more accurate reading, especially when averaging over a period in which the power varies over a wide dynamic range. Frequency is measured by timing three cycles of the voltage waveform using the upward zero crossover point as a starting point for a digital timer.

  8. Thermionic triode generates ac power

    NASA Technical Reports Server (NTRS)

    Kniazzeh, A. G. F.; Scharz, F. C.

    1970-01-01

    Electrostatic grid controls conduction cycle of thermionic diode to convert low dc output voltages to high ac power without undesirable power loss. An ac voltage applied to the grid of this new thermionic triode enables it to convert heat directly into high voltage electrical power.

  9. Automated ac galvanomagnetic measurement system

    NASA Technical Reports Server (NTRS)

    Szofran, F. R.; Espy, P. N.

    1985-01-01

    An automated, ac galvanomagnetic measurement system is described. Hall or van der Pauw measurements in the temperature range 10-300 K can be made at a preselected magnetic field without operator attendance. Procedures to validate sample installation and correct operation of other system functions, such as magnetic field and thermometry, are included. Advantages of ac measurements are discussed.

  10. Development of Ulta-Efficient Electric Motors

    SciTech Connect

    Shoykhet, B.; Schiferl, R.; Duckworth, R.; Rey, C.M.; Schwenterly, S.W.; Gouge, M.J.

    2008-05-01

    Electric motors utilize a large amount of electrical energy in utility and industrial applications. Electric motors constructed with high temperature superconducting (HTS) materials have the potential to dramatically reduce electric motor size and losses. HTS motors are best suited for large motor applications at ratings above 1000 horsepower (hp), where the energy savings from the efficiency improvement can overcome the additional power required to keep the superconductors on the rotor cooled. Large HTS based motors are expected to be half the volume and have half the losses of conventional induction motors of the same rating. For a 5000 hp industrial motor, this energy savings can result in $50,000 in operating cost savings over the course of a single year of operation. Since large horsepower motors utilize (or convert) about 30% of the electrical power generated in the United States and about 70% of large motors are candidates for replacement by HTS motors, the annual energy savings potential through the utilization of HTS motors can be up to $1 Billion in the United States alone. Research in the application of HTS materials to electric motors has lead to a number of HTS motor prototypes yet no industrial HTS motor product has yet been introduced. These motor demonstrations have been synchronous motors with HTS field windings, on the rotor. Figure 1-1 shows a solid model rendering of this type of motor. The rotor winding is made with HTS coils that are held at cryogenic temperature by introducing cooling fluid from the cryocooler to the rotor through a transfer coupling. The stator winding is made of copper wire. The HTS winding is thermally isolated from the warm armature and motor shafts by a vacuum insulation space and through the use of composite torque tubes. The stator in Figure 1-1 is an air core stator in that the stator teeth and a small part of the yoke is made up of nonmagnetic material so the magnetic fields distribute themselves as if in air

  11. Condition monitoring of machinery using motor current signature analysis

    SciTech Connect

    Kryter, R.C.; Haynes, H.D.

    1989-01-01

    Motor current signature analysis (MCSA) is a powerful monitoring tool for motor-driven equipment that provides a nonintrusive means for detecting the presence of mechanical and electrical abnormalities in the motor and the driven equipment, including altered conditions in the process ''downstream'' of the motor-driven equipment. It was developed at the Oak Ridge National Laboratory as a means for determining the effects of aging and service wear systems, but it is applicable to a broad range of machinery. MCSA is based on the recognition that an electric motor (ac or dc) driving a mechanical load acts as an efficient and permanently available transducer by sensing mechanical load variations, large and small, long-term and rapid, and converting them into variations in the induced current generated in the motor windings. These motor current variations are carried by the electrical cables processes as desired. Motor current signatures, obtained in both time and over time to provide early indication of degradation. Successful applications of MCSA technology (patent applied for) include not only motor-operated valves but also pumps of various designs, blowers, and air conditioning systems. Examples are presented briefly, and speculation regarding the applicability of MCSA to a broader range of equipment monitoring and production line testing is also given. 1 ref., 13 figs.

  12. Assessment of US electric vehicle programs with ac powertrains

    SciTech Connect

    Kevala, R.J. . Transportation Consulting Div.)

    1990-02-01

    AC powertrain technology is a promising approach to improving the performance of electric vehicles. Four major programs are now under way in the United States to develop ac powertrains: the Ford/General Electric single-shaft electric propulsion system (ETX-II), the Eaton dual-shaft electric propulsion system (DSEP), the Jet Propulsion Laboratories (JPL) integrated ac motor drive and recharge system, and the Massachusetts Institute of Technology (MIT) variable reluctance motor (VRM) drive. The JPL program is sponsored by EPRI; the other three programs are funded by the US Department of Energy. This preliminary assessment of the four powertrain programs focuses on potential performance, costs, safety, and commercial feasibility. Interviews with program personnel were supplemented by computer simulations of electric vehicle performance using the four systems. Each of the four powertrains appears superior to standard dc powertrain technology in terms of performance and weight. The powertrain technologies studied in this assessment are at varying degrees of technological maturity. One or more of the systems may be ready for incorporation into an advanced electric vehicle during the early 1990s. Each individual report will have a separate abstract. 5 refs., 37 figs., 29 tabs.

  13. Directed flux motor

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A directed flux motor described utilizes the directed magnetic flux of at least one magnet through ferrous material to drive different planetary gear sets to achieve capabilities in six actuated shafts that are grouped three to a side of the motor. The flux motor also utilizes an interwoven magnet configuration which reduces the overall size of the motor. The motor allows for simple changes to modify the torque to speed ratio of the gearing contained within the motor as well as simple configurations for any number of output shafts up to six. The changes allow for improved manufacturability and reliability within the design.

  14. Flagellar motor based micro hybrid devices.

    PubMed

    Tung, S; Kim, J-W

    2004-01-01

    We are in the process of developing a series of micro hybrid devices based on tethered flagellar motors. Examples of the devices include a microfluidic pump and a micro AC dynamo. The microfluidic pump is realized through the tethering of a harmless strain of Escherichia coli cells to a MEMS based micro channel. Each E. coli cell is about 3 mum long and 1 mum in diameter, with several flagella that are driven at the base by molecular rotary motors. The operational principle of the micro pump is based on the viscous pumping effect where continuous rotation of the tethered cells forms a fluidic conveyor belt that 'drags' fluid from one end of the channel to the other. We used hydrodynamic loading to synchronize cell rotation in order to maximize the fluid pumping capability. The micro dynamo is realized through the integration of tethered flagellar motors with micro ferromagnetic beads and micro copper coils. The micro dynamo generates AC power by using the tethered cells to create a rotating magnetic field around the copper coils. Preliminary result indicates a high power density when compared to other biologically based micro power generators. PMID:17270806

  15. Fully digital controlled A.C. servo engraving machine based on DEC4DA

    NASA Astrophysics Data System (ADS)

    Shu, Zhibing; Chen, Xianfeng; Zhang, Hairong; Huang, Yiqun; Yan, Caizhong

    2005-12-01

    A novel engraving machine (NUT-1A) is presented, in which fully digital controlled AC system based on DEC4DA was used to improve the machining precision and sensitivity. This engraving machine was constructed around AC servo motor with encoder, controlled by a servo motor control card - DEC4DA. As the upper unit of AC servo motor, DEC4DA was a numerical control generator, which received pulses form CPU by ISA bus, and these pulses were amplified and converted to drive AC servo actuator. This novel engraving machine can achieve a higher positioning accuracy of +/-0.01mm and positioning repetition of +/-0.005mm, and its resolution is 0.001mm/0.0001mm. Moreover, because of multi-closed loops were used in the system, the steady and transient performances are more excellent. This system ensures a much quicker current regulation in closed-loop operation, of acceleration and braking in both directions, as well as stable speed characteristics. Amplifier boards are protected against excessive current, excessive temperature and short circuiting of the motor supply cables.

  16. Modeling Of Permanent Magnet Motor Drives

    NASA Astrophysics Data System (ADS)

    Pillay, P.; Krishnan, R.

    1987-10-01

    Recent research has indicated that the permanent magnet motor drives which include the permanent magnet synchronous motor (PMSM) and the brushless DC motor (BDCM) could become serious competitors to the induction motor for servo applications. The PMSM has a sinusoidal back emf and requires sinusoidal stator currents to produce constant torque while the BDCM has a trapezoidal back emf and requires rectangular stator currents to produce constant torque. The PMSM is very similar to the wound rotor synchronous machine except that the PMSM that is used for servo applications tend not to have any damper windings and excitation is provided by a permanent magnet instead of a field winding. Hence the d,q model of the PMSM can be derived from the well known model of the synchronous machine with the equations of the damper windings and field current dynamics removed. Because of the nonsinusoidal variation of the mutual inductances between the stator and rotor in the BDCM, it is also shown in this paper that no particular advantage exists in transforming the abc equations of the BCDM to the d,q frame. Hence the solution of the original abc equations is proposed for the BDCM.

  17. Current Sensor Offset and Motor Parameter Variations Estimation Method for PM Motor by Using Current Simulator

    NASA Astrophysics Data System (ADS)

    Sazawa, Masaki; Senko, Tomohiro; Uenaka, Yutaro; Ohishi, Kiyoshi

    The servo system of a PM motor is required to have a fine torque response and fine speed response. The current controller of the PM motor should have a fine current response. However, when the current sensors of the U phase and V phase have offset values, the servo system of the PM motor shows a torque ripple and cannot accurately identify motor parameters such as the motor resistance Ra and motor inductance La. In order to overcome these problems, this paper proposes a new method for the fine estimation and automatic adjustment of current sensor offsets and the electrical parameters of the PM motor. The proposed method involves the use of a real-time algorithm and a current simulator, which is operated using a DSP software system. The experimental results of this study confirm that the proposed method satisfactorily estimates the offsets of the current of sensors of theU phase and V phase, Ra, and La accurately; the method also helps in the fine self-tuning of the current controller of the servo system.

  18. Fine motor control

    MedlinePlus

    ... figure out the child's developmental age. Children develop fine motor skills over time, by practicing and being taught. To have fine motor control, children need: Awareness and planning Coordination ...

  19. Chronic motor tic disorder

    MedlinePlus

    Chronic vocal tic disorder; Tic - chronic motor tic disorder ... Chronic motor tic disorder is more common than Tourette syndrome . Chronic tics may be forms of Tourette syndrome. Tics usually start ...

  20. MOV motor and gearbox performance under design basis loads

    SciTech Connect

    DeWall, K.G.; Watkins, J.C.; Weidenhamer, G.H.

    1998-06-01

    This paper describes the results of valve testing sponsored by the US Nuclear Regulatory Commission, Office of Nuclear Regulatory Research and conducted at the Idaho National Engineering and Environmental Laboratory. The research objective was to evaluate the capabilities of specific actuator motor and gearbox assemblies under various design basis loading conditions. The testing was performed using the motor-operated valve load simulator, a test fixture that simulates the stem load profiles a valve actuator would experience when closing a valve against flow and pressure loadings. The authors tested five typical motors (four ac motors and one dc motor) with three gearbox assemblies at conditions a motor might experience in a power plant, including such off-normal conditions as operation at high temperature and reduced voltage. The authors also determined the efficiency of the actuator gearbox. The testing produced the following significant results: all five motors operated at or above their rated torque during tests at full voltage and ambient temperature; for all five motors (dc as well as ac), the actual torque loss due to voltage degradation was greater than the torque loss predicted using common methods; startup torques in locked rotor tests compared well with stall torques in dynamometer-type tests; the methods commonly used to predict torque losses due to elevated operating temperatures sometimes bounded the actual losses, but not in all cases; the greatest discrepancy involved the prediction for the dc motor; running efficiencies published by the manufacturer for actuator gearboxes were higher than the actual efficiencies determined from testing, in some instances, the published pullout efficiencies were also higher than the actual values; operation of the gearbox at elevated temperature did not affect the operating efficiency.