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. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

An Efficient Fuzzy Controller Design for Parallel Connected Induction Motor Drives

NASA Astrophysics Data System (ADS)

Usha, S.; Subramani, C.

2018-04-01

Generally, an induction motors are highly non-linear and has a complex time varying dynamics. This makes the speed control of an induction motor a challenging issue in the industries. But, due to the recent trends in the power electronic devices and intelligent controllers, the speed control of the induction motor is achieved by including non-linear characteristics also. Conventionally a single inverter is used to run one induction motor in industries. In the traction applications, two or more inductions motors are operated in parallel to reduce the size and cost of induction motors. In this application, the parallel connected induction motors can be driven by a single inverter unit. The stability problems may introduce in the parallel operation under low speed operating conditions. Hence, the speed deviations should be reduce with help of suitable controllers. The speed control of the parallel connected system is performed by PID controller and fuzzy logic controller. In this paper the speed response of the induction motor for the rating of IHP, 1440 rpm, and 50Hz with these controller are compared in time domain specifications. The stability analysis of the system also performed under low speed using matlab platform. The hardware model is developed for speed control using fuzzy logic controller which exhibited superior performances over the other controller.

Online Monitoring of Induction Motors

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 amore » limited experiment with 40HP to seek the Remaining Useful Life Database of the FW PHM Suite.« less

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.

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.

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.

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.

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.

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.

Gli function is essential for motor neuron induction in zebrafish.

PubMed

Vanderlaan, Gary; Tyurina, Oksana V; Karlstrom, Rolf O; Chandrasekhar, Anand

2005-06-15

The Gli family of zinc-finger transcription factors mediates Hedgehog (Hh) signaling in all vertebrates. However, their roles in ventral neural tube patterning, in particular motor neuron induction, appear to have diverged across species. For instance, cranial motor neurons are essentially lost in zebrafish detour (gli1(-)) mutants, whereas motor neuron development is unaffected in mouse single gli and some double gli knockouts. Interestingly, the expression of some Hh-regulated genes (ptc1, net1a, gli1) is mostly unaffected in the detour mutant hindbrain, suggesting that other Gli transcriptional activators may be involved. To better define the roles of the zebrafish gli genes in motor neuron induction and in Hh-regulated gene expression, we examined these processes in you-too (yot) mutants, which encode dominant repressor forms of Gli2 (Gli2(DR)), and following morpholino-mediated knockdown of gli1, gli2, and gli3 function. Motor neuron induction at all axial levels was reduced in yot (gli2(DR)) mutant embryos. In addition, Hh target gene expression at all axial levels except in rhombomere 4 was also reduced, suggesting an interference with the function of other Glis. Indeed, morpholino-mediated knockdown of Gli2(DR) protein in yot mutants led to a suppression of the defective motor neuron phenotype. However, gli2 knockdown in wild-type embryos generated no discernable motor neuron phenotype, while gli3 knockdown reduced motor neuron induction in the hindbrain and spinal cord. Significantly, gli2 or gli3 knockdown in detour (gli1(-)) mutants revealed roles for Gli2 and Gli3 activator functions in ptc1 expression and spinal motor neuron induction. Similarly, gli1 or gli3 knockdown in yot (gli2(DR)) mutants resulted in severe or complete loss of motor neurons, and of ptc1 and net1a expression, in the hindbrain and spinal cord. In addition, gli1 expression was greatly reduced in yot mutants following gli3, but not gli1, knockdown, suggesting that Gli3 activator

Modernization of gas-turbine engines with high-frequency induction motors

NASA Astrophysics Data System (ADS)

Abramovich, B. N.; Sychev, Yu A.; Kuznetsov, P. A.

2018-03-01

Main tendencies of growth of electric energy consumption in general and mining industries were analyzed in the paper. A key role of electric drive in this process was designated. A review about advantages and disadvantages of unregulated gearboxes with mechanical units that are commonly used in domestically produced gas-turbine engines was made. This review allows one to propose different gas-turbine engines modernization schemes with the help of PWM-driven high-frequency induction motors. Induction motors with the double rotor winding were examined. A simulation of high-frequency induction motors with double rotor windings in Matlab-Simulink software was carried out based on equivalent circuit parameters. Obtained characteristics of new motors were compared with serially produced analogues. After the simulation, results were implemented in the real prototype.

Slot Optimization Design of Induction Motor for Electric Vehicle

NASA Astrophysics Data System (ADS)

Shen, Yiming; Zhu, Changqing; Wang, Xiuhe

2018-01-01

Slot design of induction motor has a great influence on its performance. The RMxprt module based on magnetic circuit method can be used to analyze the influence of rotor slot type on motor characteristics and optimize slot parameters. In this paper, the authors take an induction motor of electric vehicle for a typical example. The first step of the design is to optimize the rotor slot by RMxprt, and then compare the main performance of the motor before and after the optimization through Ansoft Maxwell 2D. After that, the combination of optimum slot type and the optimum parameters are obtained. The results show that the power factor and the starting torque of the optimized motor have been improved significantly. Furthermore, the electric vehicle works at a better running status after the optimization.

Doubly fed induction generator wind turbines with fuzzy controller: a survey.

PubMed

Sathiyanarayanan, J S; Kumar, A Senthil

2014-01-01

Wind energy is one of the extraordinary sources of renewable energy due to its clean character and free availability. With the increasing wind power penetration, the wind farms are directly influencing the power systems. The majority of wind farms are using variable speed wind turbines equipped with doubly fed induction generators (DFIG) due to their advantages over other wind turbine generators (WTGs). Therefore, the analysis of wind power dynamics with the DFIG wind turbines has become a very important research issue, especially during transient faults. This paper presents fuzzy logic control of doubly fed induction generator (DFIG) wind turbine in a sample power system. Fuzzy logic controller is applied to rotor side converter for active power control and voltage regulation of wind turbine.

Doubly Fed Induction Generator Wind Turbines with Fuzzy Controller: A Survey

PubMed Central

Sathiyanarayanan, J. S.; Senthil Kumar, A.

2014-01-01

Wind energy is one of the extraordinary sources of renewable energy due to its clean character and free availability. With the increasing wind power penetration, the wind farms are directly influencing the power systems. The majority of wind farms are using variable speed wind turbines equipped with doubly fed induction generators (DFIG) due to their advantages over other wind turbine generators (WTGs). Therefore, the analysis of wind power dynamics with the DFIG wind turbines has become a very important research issue, especially during transient faults. This paper presents fuzzy logic control of doubly fed induction generator (DFIG) wind turbine in a sample power system. Fuzzy logic controller is applied to rotor side converter for active power control and voltage regulation of wind turbine. PMID:25028677

Soft Computing Application in Fault Detection of Induction Motor

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

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

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.

Fundamentals of electric power conversion. Volume 2, Energy-efficient polyphase AC induction motors, final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Umans, S.D.

1992-12-01

Its rugged nature and straightforward design make the induction motor the most commonly used type of electric motor. This motor ranges in size fro the fractional-horsepower, single-phase motors found in household appliances to polyphase motors rated at thousands of horsepower for industrial applications. Volume 1 of this report describes the function of induction motors, their characteristics, and induction motor testing. Volume 2 describes the characteristics of high-efficiency induction motors, with emphasis on the techniques used to obtain high efficiency. This two-volume report is written in nontechnical language and is intended for readers who require background from applications, marketing, motor planning,more » or managerial perspective.« less

The association between brain activity and motor imagery during motor illusion induction by vibratory stimulation.

PubMed

Kodama, Takayuki; Nakano, Hideki; Katayama, Osamu; Murata, Shin

2017-01-01

The association between motor imagery ability and brain neural activity that leads to the manifestation of a motor illusion remains unclear. In this study, we examined the association between the ability to generate motor imagery and brain neural activity leading to the induction of a motor illusion by vibratory stimulation. The sample consisted of 20 healthy individuals who did not have movement or sensory disorders. We measured the time between the starting and ending points of a motor illusion (the time to illusion induction, TII) and performed electroencephalography (EEG). We conducted a temporo-spatial analysis on brain activity leading to the induction of motor illusions using the EEG microstate segmentation method. Additionally, we assessed the ability to generate motor imagery using the Japanese version of the Movement Imagery Questionnaire-Revised (JMIQ-R) prior to performing the task and examined the associations among brain neural activity levels as identified by microstate segmentation method, TII, and the JMIQ-R scores. The results showed four typical microstates during TII and significantly higher neural activity in the ventrolateral prefrontal cortex, primary sensorimotor area, supplementary motor area (SMA), and inferior parietal lobule (IPL). Moreover, there were significant negative correlations between the neural activity of the primary motor cortex (MI), SMA, IPL, and TII, and a significant positive correlation between the neural activity of the SMA and the JMIQ-R scores. These findings suggest the possibility that a neural network primarily comprised of the neural activity of SMA and M1, which are involved in generating motor imagery, may be the neural basis for inducing motor illusions. This may aid in creating a new approach to neurorehabilitation that enables a more robust reorganization of the neural base for patients with brain dysfunction with a motor function disorder.

The association between brain activity and motor imagery during motor illusion induction by vibratory stimulation

PubMed Central

Kodama, Takayuki; Nakano, Hideki; Katayama, Osamu; Murata, Shin

2017-01-01

Background: The association between motor imagery ability and brain neural activity that leads to the manifestation of a motor illusion remains unclear. Objective: In this study, we examined the association between the ability to generate motor imagery and brain neural activity leading to the induction of a motor illusion by vibratory stimulation. Methods: The sample consisted of 20 healthy individuals who did not have movement or sensory disorders. We measured the time between the starting and ending points of a motor illusion (the time to illusion induction, TII) and performed electroencephalography (EEG). We conducted a temporo-spatial analysis on brain activity leading to the induction of motor illusions using the EEG microstate segmentation method. Additionally, we assessed the ability to generate motor imagery using the Japanese version of the Movement Imagery Questionnaire-Revised (JMIQ-R) prior to performing the task and examined the associations among brain neural activity levels as identified by microstate segmentation method, TII, and the JMIQ-R scores. Results: The results showed four typical microstates during TII and significantly higher neural activity in the ventrolateral prefrontal cortex, primary sensorimotor area, supplementary motor area (SMA), and inferior parietal lobule (IPL). Moreover, there were significant negative correlations between the neural activity of the primary motor cortex (MI), SMA, IPL, and TII, and a significant positive correlation between the neural activity of the SMA and the JMIQ-R scores. Conclusion: These findings suggest the possibility that a neural network primarily comprised of the neural activity of SMA and M1, which are involved in generating motor imagery, may be the neural basis for inducing motor illusions. This may aid in creating a new approach to neurorehabilitation that enables a more robust reorganization of the neural base for patients with brain dysfunction with a motor function disorder. PMID:29172013

Study of linear induction motor characteristics : the Mosebach model

DOT National Transportation Integrated Search

1976-05-31

This report covers the Mosebach theory of the double-sided linear induction motor, starting with the ideallized model and accompanying assumptions, and ending with relations for thrust, airgap power, and motor efficiency. Solutions of the magnetic in...

Study of linear induction motor characteristics : the Oberretl model

DOT National Transportation Integrated Search

1975-05-30

The Oberretl theory of the double-sided linear induction motor (LIM) is examined, starting with the idealized model and accompanying assumptions, and ending with relations for predicted thrust, airgap power, and motor efficiency. The effect of varyin...

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.

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.

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.

An Improved Power Quality BIBRED Converter-Based VSI-Fed BLDC Motor Drive

NASA Astrophysics Data System (ADS)

Singh, Bhim; Bist, Vashist

2014-01-01

This paper presents an IHQRR (integrated high-quality rectifier regulator) BIBRED (boost integrated buck rectifier energy storage DC-DC) converter-based VSI (voltage source inverter)-fed BLDC (brushless DC) motor drive. The speed control of BLDC motor is achieved by controlling the DC link voltage of the VSI using a single voltage sensor. This allows VSI to operate in fundamental frequency switching mode for electronic commutation of BLDC motor which reduces the switching losses due to high-frequency switching used in conventional approach of PWM (pulse width modulation)-based VSI-fed BLDC motor drive. A BIBRED converter is operated in a dual-DCM (discontinuous conduction mode) thus using a voltage follower approach for PFC (power factor correction) and DC link voltage control. The performance of the proposed drive is evaluated for improved power quality over a wide range of speed control and supply voltage variation for demonstrating the behavior of proposed drive. The power quality indices thus obtained are within the recommended limits by international PQ (power quality) standards such as IEC 61000-3-2.

The Design of Software for Three-Phase Induction Motor Test System

NASA Astrophysics Data System (ADS)

Haixiang, Xu; Fengqi, Wu; Jiai, Xue

2017-11-01

The design and development of control system software is important to three-phase induction motor test equipment, which needs to be completely familiar with the test process and the control procedure of test equipment. In this paper, the software is developed according to the national standard (GB/T1032-2005) about three-phase induction motor test method by VB language. The control system and data analysis software and the implement about motor test system are described individually, which has the advantages of high automation and high accuracy.

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.

Fuzzy – PI controller to control the velocity parameter of Induction Motor

NASA Astrophysics Data System (ADS)

Malathy, R.; Balaji, V.

2018-04-01

The major application of Induction motor includes the usage of the same in industries because of its high robustness, reliability, low cost, highefficiency and good self-starting capability. Even though it has the above mentioned advantages, it also have some limitations: (1) the standard motor is not a true constant-speed machine, itsfull-load slip varies less than 1 % (in high-horsepower motors).And (2) it is not inherently capable of providing variable-speedoperation. In order to solve the above mentioned problem smart motor controls and variable speed controllers are used. Motor applications involve non linearity features, which can be controlled by Fuzzy logic controller as it is capable of handling those features with high efficiency and it act similar to human operator. This paper presents individuality of the plant modelling. The fuzzy logic controller (FLC)trusts on a set of linguistic if-then rules, a rule-based Mamdani for closed loop Induction Motor model. Themotor model is designed and membership functions are chosenaccording to the parameters of the motor model. Simulation results contains non linearity in induction motor model. A conventional PI controller iscompared practically to fuzzy logic controller using Simulink.

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.

Effect of different methods of pulse width modulation on power losses in an induction motor

NASA Astrophysics Data System (ADS)

Gulyaev, Alexander; Fokin, Dmitrii; Shuharev, Sergey; Ten, Evgenii

2017-10-01

We consider the calculation of modulation power losses in a system “induction motor-inverter” for various pulse width modulation (PWM) methods of the supply voltage. Presented values of modulation power losses are the result of modeling a system “DC link - two-level three-phase voltage inverter - induction motor - load”. In this study the power losses in a system “induction motor - inverter” are computed, as well as losses caused by higher harmonics of PWM supply voltage, followed by definition of active power consumed by the DC link for a specified value mechanical power on the induction motor shaft. Mechanical power was determined by the rotation speed and the torque on the motor shaft in various quasi-sinusoidal supply voltage PWM modes. These calculations reveal the best coefficient of performance (COP) in a system of a variable frequency drive (VFD) with independent voltage inverter controlled by induction motor PWM.

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…

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 tomore » 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.« less

Induction motor speed control using varied duty cycle terminal voltage via PI controller

NASA Astrophysics Data System (ADS)

Azwin, A.; Ahmed, S.

2018-03-01

This paper deals with the PI speed controller for the three-phase induction motor using PWM technique. The PWM generated signal is utilized for voltage source inverter with an optimal duty cycle on a simplified induction motor model. A control algorithm for generating PWM control signal is developed. Obtained results shows that the steady state error and overshoot of the developed system is in the limit under different speed and load condition. The robustness of the control performance would be potential for induction motor performance improvement.

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.

Implementation of a new fuzzy vector control of induction motor.

PubMed

Rafa, Souad; Larabi, Abdelkader; Barazane, Linda; Manceur, Malik; Essounbouli, Najib; Hamzaoui, Abdelaziz

2014-05-01

The aim of this paper is to present a new approach to control an induction motor using type-1 fuzzy logic. The induction motor has a nonlinear model, uncertain and strongly coupled. The vector control technique, which is based on the inverse model of the induction motors, solves the coupling problem. Unfortunately, in practice this is not checked because of model uncertainties. Indeed, the presence of the uncertainties led us to use human expertise such as the fuzzy logic techniques. In order to maintain the decoupling and to overcome the problem of the sensitivity to the parametric variations, the field-oriented control is replaced by a new block control. The simulation results show that the both control schemes provide in their basic configuration, comparable performances regarding the decoupling. However, the fuzzy vector control provides the insensitivity to the parametric variations compared to the classical one. The fuzzy vector control scheme is successfully implemented in real-time using a digital signal processor board dSPACE 1104. The efficiency of this technique is verified as well as experimentally at different dynamic operating conditions such as sudden loads change, parameter variations, speed changes, etc. The fuzzy vector control is found to be a best control for application in an induction motor. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Multilevel DC Link Inverter for Brushless Permanent Magnet Motors with Very Low Inductance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, G.J.

2001-10-29

Due to their long effective air gaps, permanent magnet motors tend to have low inductance. The use of ironless stator structure in present high power PM motors (several tens of kWs) reduces the inductance even further (< 100 {micro}H). This low inductance imposes stringent current regulation demands for the inverter to obtain acceptable current ripple. An analysis of the current ripple for these low inductance brushless PM motors shows that a standard inverter with the most commonly used IGBT switching devices cannot meet the current regulation demands and will produce unacceptable current ripples due to the IGBT's limited switching frequency.more » This paper introduces a new multilevel dc link inverter, which can dramatically reduce the current ripple for brushless PM motor drives. The operating principle and design guidelines are included.« less

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.

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.

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

Fault detection and diagnosis of induction motors using motor current signature analysis and a hybrid FMM-CART model.

PubMed

Seera, Manjeevan; Lim, Chee Peng; Ishak, Dahaman; Singh, Harapajan

2012-01-01

In this paper, a novel approach to detect and classify comprehensive fault conditions of induction motors using a hybrid fuzzy min-max (FMM) neural network and classification and regression tree (CART) is proposed. The hybrid model, known as FMM-CART, exploits the advantages of both FMM and CART for undertaking data classification and rule extraction problems. A series of real experiments is conducted, whereby the motor current signature analysis method is applied to form a database comprising stator current signatures under different motor conditions. The signal harmonics from the power spectral density are extracted as discriminative input features for fault detection and classification with FMM-CART. A comprehensive list of induction motor fault conditions, viz., broken rotor bars, unbalanced voltages, stator winding faults, and eccentricity problems, has been successfully classified using FMM-CART with good accuracy rates. The results are comparable, if not better, than those reported in the literature. Useful explanatory rules in the form of a decision tree are also elicited from FMM-CART to analyze and understand different fault conditions of induction motors.

Fundamentals of electric power conversion. Volume 1, Operating characteristics and testing of AC induction motors, final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Umans, S.D.

1992-12-01

Its rugged nature and straightforward design make the induction motor the most commonly used type of electric motor. This motor ranges in size from the fractional-horsepower, single-phase motors found in household appliances to polyphase motors rated at thousands of horsepower for industrial applications. Volume 1 of this report describes the function of induction motors, their characteristics, and induction motor testing. Volume 2 describes the characteristics of high-efficiency induction motors, with emphasis on the techniques used to obtain high efficiency. This two-volume report is written in nontechnical language and is intended for readers who require background from an applications, marketing, motormore » planning, or managerial perspective.« less

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.

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.

Accuracy of iron loss estimation in induction motors by using different iron loss models

NASA Astrophysics Data System (ADS)

Štumberger, B.; Hamler, A.; Goričan, V.; Jesenik, M.; Trlep, M.

2004-05-01

The paper presents iron loss estimation in a three-phase induction motor by using different iron loss models for the posterior iron loss calculation. The iron losses were determined by using modeled properties of used electrical steel and calculated distribution of magnetic induction B(t) in all parts of the motor by using 2D finite element software for a complete cycle of field variation. The comparison between estimated and measured core losses for a 4kW induction motor at no-load in dependency on supply voltage is given.

Neural network based control of Doubly Fed Induction Generator in wind power generation

NASA Astrophysics Data System (ADS)

Barbade, Swati A.; Kasliwal, Prabha

2012-07-01

To complement the other types of pollution-free generation wind energy is a viable option. Previously wind turbines were operated at constant speed. The evolution of technology related to wind systems industry leaded to the development of a generation of variable speed wind turbines that present many advantages compared to the fixed speed wind turbines. In this paper the phasor model of DFIG is used. This paper presents a study of a doubly fed induction generator driven by a wind turbine connected to the grid, and controlled by artificial neural network ANN controller. The behaviour of the system is shown with PI control, and then as controlled by ANN. The effectiveness of the artificial neural network controller is compared to that of a PI controller. The SIMULINK/MATLAB simulation for Doubly Fed Induction Generator and corresponding results and waveforms are displayed.

Tissue Plasminogen Activator Induction in Purkinje Neurons After Cerebellar Motor Learning

NASA Astrophysics Data System (ADS)

Seeds, Nicholas W.; Williams, Brian L.; Bickford, Paula C.

1995-12-01

The cerebellar cortex is implicated in the learning of complex motor skills. This learning may require synaptic remodeling of Purkinje cell inputs. An extracellular serine protease, tissue plasminogen activator (tPA), is involved in remodeling various nonneural tissues and is associated with developing and regenerating neurons. In situ hybridization showed that expression of tPA messenger RNA was increased in the Purkinje neurons of rats within an hour of their being trained for a complex motor task. Antibody to tPA also showed the induction of tPA protein associated with cerebellar Purkinje cells. Thus, the induction of tPA during motor learning may play a role in activity-dependent synaptic plasticity.

Performance characteristics of three-phase induction motors

NASA Technical Reports Server (NTRS)

Wood, M. E.

1977-01-01

An investigation into the characteristics of three phase, 400 Hz, induction motors of the general type used on aircraft and spacecraft is summarized. Results of laboratory tests are presented and compared with results from a computer program. Representative motors were both tested and simulated under nominal conditions as well as off nominal conditions of temperature, frequency, voltage magnitude, and voltage balance. Good correlation was achieved between simulated and laboratory results. The primary purpose of the program was to verify the simulation accuracy of the computer program, which in turn will be used as an analytical tool to support the shuttle orbiter.

A Deep Learning Approach for Fault Diagnosis of Induction Motors in Manufacturing

NASA Astrophysics Data System (ADS)

Shao, Si-Yu; Sun, Wen-Jun; Yan, Ru-Qiang; Wang, Peng; Gao, Robert X.

2017-11-01

Extracting features from original signals is a key procedure for traditional fault diagnosis of induction motors, as it directly influences the performance of fault recognition. However, high quality features need expert knowledge and human intervention. In this paper, a deep learning approach based on deep belief networks (DBN) is developed to learn features from frequency distribution of vibration signals with the purpose of characterizing working status of induction motors. It combines feature extraction procedure with classification task together to achieve automated and intelligent fault diagnosis. The DBN model is built by stacking multiple-units of restricted Boltzmann machine (RBM), and is trained using layer-by-layer pre-training algorithm. Compared with traditional diagnostic approaches where feature extraction is needed, the presented approach has the ability of learning hierarchical representations, which are suitable for fault classification, directly from frequency distribution of the measurement data. The structure of the DBN model is investigated as the scale and depth of the DBN architecture directly affect its classification performance. Experimental study conducted on a machine fault simulator verifies the effectiveness of the deep learning approach for fault diagnosis of induction motors. This research proposes an intelligent diagnosis method for induction motor which utilizes deep learning model to automatically learn features from sensor data and realize working status recognition.

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.

Comparative evaluation of power factor impovement techniques for squirrel cage induction motors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spee, R.; Wallace, A.K.

1992-04-01

This paper describes the results obtained from a series of tests of relatively simple methods of improving the power factor of squirrel-cage induction motors. The methods, which are evaluated under controlled laboratory conditions for a 10-hp, high-efficiency motor, include terminal voltage reduction; terminal static capacitors; and a floating'' winding with static capacitors. The test results are compared with equivalent circuit model predictions that are then used to identify optimum conditions for each of the power factor improvement techniques compared with the basic induction motor. Finally, the relative economic value, and the implications of component failures, of the three methods aremore » discussed.« less

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.

Design optimization of high frequency transformer with controlled leakage inductance for current fed dual active bridge converter

NASA Astrophysics Data System (ADS)

Jung, Tae-Uk; Kim, Myung-Hwan; Yoo, Jin-Hyung

2018-05-01

Current fed dual active bridge converters for photovoltaic generation may typically require a given leakage or extra inductance in order to provide proper control of the currents. Therefore, the many researches have been focused on the leakage inductance control of high frequency transformer to integrate an extra inductor. In this paper, an asymmetric winding arrangement to get the controlled leakage inductance for the high frequency transformer is proposed to improve the efficiency of the current fed dual active bridge converter. In order to accurate analysis, a coupled electromagnetic analysis model of transformer connected with high frequency switching circuit is used. A design optimization procedure for high efficiency is also presented using design analysis model, and it is verified by the experimental result.

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.

Two models for identification and predicting behaviour of an induction motor system

NASA Astrophysics Data System (ADS)

Kuo, Chien-Hsun

2018-01-01

System identification or modelling is the process of building mathematical models of dynamical systems based on the available input and output data from the systems. This paper introduces system identification by using ARX (Auto Regressive with eXogeneous input) and ARMAX (Auto Regressive Moving Average with eXogeneous input) models. Through the identified system model, the predicted output could be compared with the measured one to help prevent the motor faults from developing into a catastrophic machine failure and avoid unnecessary costs and delays caused by the need to carry out unscheduled repairs. The induction motor system is illustrated as an example. Numerical and experimental results are shown for the identified induction motor system.

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.

29. INDUCTION MOTOR (6600 VOLTS, 5750 H.P.) DRIVES THE 21INCH ...

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

29. INDUCTION MOTOR (6600 VOLTS, 5750 H.P.) DRIVES THE 21-INCH AND 18-INCH BILLET MILLS. MOTOR WAS MANUFACTURED BY THE GENERAL ELECTRIC COMPANY, SCHENECTADY, NEW YORK. - Corrigan, McKinney Steel Company, 3100 East Forty-fifth Street, Cleveland, Cuyahoga County, OH

Evaluation of linear induction motor characteristics : the Yamamura model

DOT National Transportation Integrated Search

1975-04-30

The Yamamura theory of the double-sided linear induction motor (LIM) excited by a constant current source is discussed in some detail. The report begins with a derivation of thrust and airgap power using the method of vector potentials and theorem of...

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.

Novel Observer Scheme of Fuzzy-MRAS Sensorless Speed Control of Induction Motor Drive

NASA Astrophysics Data System (ADS)

Chekroun, S.; Zerikat, M.; Mechernene, A.; Benharir, N.

2017-01-01

This paper presents a novel approach Fuzzy-MRAS conception for robust accurate tracking of induction motor drive operating in a high-performance drives environment. Of the different methods for sensorless control of induction motor drive the model reference adaptive system (MRAS) finds lot of attention due to its good performance. The analysis of the sensorless vector control system using MRAS is presented and the resistance parameters variations and speed observer using new Fuzzy Self-Tuning adaptive IP Controller is proposed. In fact, fuzzy logic is reminiscent of human thinking processes and natural language enabling decisions to be made based on vague information. The present approach helps to achieve a good dynamic response, disturbance rejection and low to plant parameter variations of the induction motor. In order to verify the performances of the proposed observer and control algorithms and to test behaviour of the controlled system, numerical simulation is achieved. Simulation results are presented and discussed to shown the validity and the performance of the proposed observer.

A Drive Method for Small Inductance PM Motor Under No-Load Condition

NASA Astrophysics Data System (ADS)

Tanaka, Daisuke; Ohishi, Kiyoshi

The harmonic wave of the exciting current of the motor is generated by the pulsewidth modulated voltage of the inverter. The motors that have low inpedance genetate more harmonics and make larger iron loss. This paper describes an implementation of drive control for a small inductance permanent-magnet motor drive. A comparative experiment has been carried out with conventional methods and the utility of the proposed method has been verified.

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.

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.

Advanced simulation model for IPM motor drive with considering phase voltage and stator inductance

NASA Astrophysics Data System (ADS)

Lee, Dong-Myung; Park, Hyun-Jong; Lee, Ju

2016-10-01

This paper proposes an advanced simulation model of driving system for Interior Permanent Magnet (IPM) BrushLess Direct Current (BLDC) motors driven by 120-degree conduction method (two-phase conduction method, TPCM) that is widely used for sensorless control of BLDC motors. BLDC motors can be classified as SPM (Surface mounted Permanent Magnet) and IPM motors. Simulation model of driving system with SPM motors is simple due to the constant stator inductance regardless of the rotor position. Simulation models of SPM motor driving system have been proposed in many researches. On the other hand, simulation models for IPM driving system by graphic-based simulation tool such as Matlab/Simulink have not been proposed. Simulation study about driving system of IPMs with TPCM is complex because stator inductances of IPM vary with the rotor position, as permanent magnets are embedded in the rotor. To develop sensorless scheme or improve control performance, development of control algorithm through simulation study is essential, and the simulation model that accurately reflects the characteristic of IPM is required. Therefore, this paper presents the advanced simulation model of IPM driving system, which takes into account the unique characteristic of IPM due to the position-dependent inductances. The validity of the proposed simulation model is validated by comparison to experimental and simulation results using IPM with TPCM control scheme.

22. DIABLO POWERHOUSE: COOLING WATER PUMPS (WESTINGHOUSE C.S. INDUCTION MOTORS), ...

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

22. DIABLO POWERHOUSE: COOLING WATER PUMPS (WESTINGHOUSE C.S. INDUCTION MOTORS), 1989. - Skagit Power Development, Diablo Powerhouse, On Skagit River, 6.1 miles upstream from Newhalem, Newhalem, Whatcom County, WA

Growth, motor, and social development in breast- and formula-fed infants of metformin-treated women with polycystic ovary syndrome.

PubMed

Glueck, Charles J; Salehi, Marzieh; Sieve, Luann; Wang, Ping

2006-05-01

To test the hypothesis that metformin during lactation versus formula feeding would have no adverse effects on infants' growth, motor-social development, or intercurrent illness. Growth, motor-social development, and illness requiring a pediatrician visit were assessed in 61 nursing infants (21 male, 40 female) and 50 formula-fed infants (19 male, 31 female) born to 92 mothers with polycystic ovary syndrome (PCOS) taking a median of 2.55 g metformin per day throughout pregnancy and lactation. Within sex, at 3 and 6 months of age, weight, height, and motor-social development did not differ (p > or = .06) between breast- and formula-fed infants. No infants had retardation of growth, motor, or social development. Intercurrent illnesses did not differ. Metformin during lactation appears to be safe and effective in the first 6 months of infancy.

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

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.

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.

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.

Performance Analysis of Three-Phase Induction Motor with AC Direct and VFD

NASA Astrophysics Data System (ADS)

Kumar, Dinesh

2018-03-01

The electrical machine analysis and performance calculation is a very important aspect of efficient drive system design. The development of power electronics devices and power converters provide smooth speed control of Induction Motors by changing the frequency of input supply. These converters, on one hand are providing a more flexible speed control that also leads to problems of harmonics and their associated ailments like pulsating torque, distorted current and voltage waveforms, increasing losses etc. This paper includes the performance analysis of three phase induction motor with three-phase AC direct and variable frequency drives (VFD). The comparison has been concluded with respect to various parameters. MATLAB-SIMULINKTM is used for the analysis.

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.

The Numerical Calculation and Experimental Measurement of the Inductance Parameters for Permanent Magnet Synchronous Motor in Electric Vehicle

NASA Astrophysics Data System (ADS)

Jiang, Chao; Qiao, Mingzhong; Zhu, Peng

2017-12-01

A permanent magnet synchronous motor with radial magnetic circuit and built-in permanent magnet is designed for the electric vehicle. Finite element numerical calculation and experimental measurement are adopted to obtain the direct axis and quadrature axis inductance parameters of the motor which are vital important for the motor control. The calculation method is simple, the measuring principle is clear, the results of numerical calculation and experimental measurement are mutual confirmation. A quick and effective method is provided to obtain the direct axis and quadrature axis inductance parameters of the motor, and then improve the design of motor or adjust the control parameters of the motor controller.

Demonstration of LenzÂ's law with an induction motor

NASA Astrophysics Data System (ADS)

Kraftmakher, Yaakov

2005-03-01

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.

Induction of motor neuron differentiation by transduction of Olig2 protein.

PubMed

Mie, Masayasu; Kaneko, Mami; Henmi, Fumiaki; Kobatake, Eiry

2012-10-26

Olig2 protein, a member of the basic helix-loop-helix transcription factor family, was introduced into the mouse embryonic carcinoma cell line P19 for induction of motor neuron differentiation. We show that Olig2 protein has the ability to permeate the cell membrane without the addition of a protein transduction domain (PTD), similar to other basic helix-loop-helix transcription factors such as MyoD and NeuroD2. Motor neuron differentiation was evaluated for the elongation of neurites and the expression of choline acetyltransferase (ChAT) mRNA, a differentiation marker of motor neurons. By addition of Olig2 protein, motor neuron differentiation was induced in P19 cells. Copyright © 2012 Elsevier Inc. All rights reserved.

Three-dimensional magnetic induction model of an octagonal edge-defined film-fed growth system

NASA Astrophysics Data System (ADS)

Rajendran, S.; Holmes, K.; Menna, A.

1994-03-01

Silicon wafers for the photovoltaic industry are produced by growing thin octagonal tubes by the edge-defined film-fed growth (EFG) process. The thermal origin of the wafer thickness variations was studied with a three-dimensional (3D) magnetic induction model. The implementation of the computer code and the significance of the computed results for improving the thickness uniformity are discussed.

Structural Design Optimization of Doubly-Fed Induction Generators Using GeneratorSE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sethuraman, Latha; Fingersh, Lee J; Dykes, Katherine L

2017-11-13

A wind turbine with a larger rotor swept area can generate more electricity, however, this increases costs disproportionately for manufacturing, transportation, and installation. This poster presents analytical models for optimizing doubly-fed induction generators (DFIGs), with the objective of reducing the costs and mass of wind turbine drivetrains. The structural design for the induction machine includes models for the casing, stator, rotor, and high-speed shaft developed within the DFIG module in the National Renewable Energy Laboratory's wind turbine sizing tool, GeneratorSE. The mechanical integrity of the machine is verified by examining stresses, structural deflections, and modal properties. The optimization results aremore » then validated using finite element analysis (FEA). The results suggest that our analytical model correlates with the FEA in some areas, such as radial deflection, differing by less than 20 percent. But the analytical model requires further development for axial deflections, torsional deflections, and stress calculations.« less

The Study of Residual Voltage of Induction Motor and the Influence of Various Parameters on the Residual Voltage

NASA Astrophysics Data System (ADS)

Zhang, Shuping; Zhao, Chen; Tan, Weipu

2017-05-01

The majority important load of industrial area is mainly composed of induction motor, it is more common that induction motor becomes sluggishness and even tripping due to the lose of power supply or other malfunction in the practical work. In this paper, space vector method is used to establish a reduced order model of induction motor, and then study the changes of motor electromagnetic after losing electricity. Based on motion equations of the rotor and magnetic flux conservation principle, it uses mathematical methods to deduce the expression of rotor current, rotor flux, the stator flux and the residual voltage of stator side. In addition, relying on thermal power plants, it uses the actual data of power plants, takes DIgsilent software to simulate the residual voltage of motor after losing electricity. analyses the influence on the residual voltage with the changes of the moment of inertia, load ratio, initial size of slip and the load characteristic of induction motor. By analysis of these, it has a more detailed understanding about the changes of residual voltage in practical application, in additional, it is more beneficial to put into standby power supply safely and effectively, moreover, reduce the influence of the input process to the whole system.

Design of motor induction 3-Phase from waste industry to generator for microhydro at isolated village

NASA Astrophysics Data System (ADS)

Rimbawati; Azis Hutasuhut, Abdul; Irsan Pasaribu, Faisal; Cholish; Muharnif

2017-09-01

There is an electric machine that can operate as a generator either single-phase or three-phase in almost every household and industry today. This electric engine cannot be labeled as a generator but can be functioned as a generator. The machine that is mentioned is “squirrel cage motors” or it is well-known as induction motor that can be found in water pumps, washing machines, fans, blowers and other industrial machines. The induction motor can be functioned as a generator when the rotational speed of the rotor is made larger than the speed of the rotary field. In this regard, this study aims to modify the remains of 3-phase induction motor to be a permanent generator. Data of research based conducted on the river flow of Rumah Sumbul Village, STM Hulu district of Deli Serdang. The method of this research is by changing rotor and stator winding on a 3 phase induction motor, so it can produce a generator with rotation speed of 500 rpm. Based on the research, it can be concluded that the output voltage generator has occurred a voltage drop 10% between before and after loading for Star circuit and 2% for Delta circuit.

High-efficiency induction motor drives using type-2 fuzzy logic

NASA Astrophysics Data System (ADS)

Khemis, A.; Benlaloui, I.; Drid, S.; Chrifi-Alaoui, L.; Khamari, D.; Menacer, A.

2018-03-01

In this work we propose to develop an algorithm for improving the efficiency of an induction motor using type-2 fuzzy logic. Vector control is used to control this motor due to the high performances of this strategy. The type-2 fuzzy logic regulators are developed to obtain the optimal rotor flux for each torque load by minimizing the copper losses. We have compared the performances of our fuzzy type-2 algorithm with the type-1 fuzzy one proposed in the literature. The proposed algorithm is tested with success on the dSPACE DS1104 system even if there is parameters variance.

Approach to Computer Implementation of Mathematical Model of 3-Phase Induction Motor

NASA Astrophysics Data System (ADS)

Pustovetov, M. Yu

2018-03-01

This article discusses the development of the computer model of an induction motor based on the mathematical model in a three-phase stator reference frame. It uses an approach that allows combining during preparation of the computer model dual methods: means of visual programming circuitry (in the form of electrical schematics) and logical one (in the form of block diagrams). The approach enables easy integration of the model of an induction motor as part of more complex models of electrical complexes and systems. The developed computer model gives the user access to the beginning and the end of a winding of each of the three phases of the stator and rotor. This property is particularly important when considering the asymmetric modes of operation or when powered by the special circuitry of semiconductor converters.

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.

Induction of mice adult bone marrow mesenchymal stem cells into functional motor neuron-like cells.

PubMed

Abdullah, Rafal H; Yaseen, Nahi Y; Salih, Shahlaa M; Al-Juboory, Ahmad Adnan; Hassan, Ayman; Al-Shammari, Ahmed Majeed

2016-11-01

The differentiation of mesenchymal stem cells (MSC) into acetylcholine secreted motor neuron-like cells, followed by elongation of the cell axon, is a promising treatment for spinal cord injury and motor neuron cell dysfunction in mammals. Differentiation is induced through a pre-induction step using Beta- mercaptoethanol (BME) followed by four days of induction with retinoic acid and sonic hedgehog. This process results in a very efficient differentiation of BM-MSCs into motor neuron-like cells. Immunocytochemistry showed that these treated cells had specific motor neural markers: microtubule associated protein-2 and acetylcholine transferase. The ability of these cells to function as motor neuron cells was assessed by measuring acetylcholine levels in a culture media during differentiation. High-performance liquid chromatography (HPLC) showed that the differentiated cells were functional. Motor neuron axon elongation was then induced by adding different concentrations of a nerve growth factor (NGF) to the differentiation media. Using a collagen matrix to mimic the natural condition of neural cells in a three-dimensional model showed that the MSCs were successfully differentiated into motor neuron-like cells. This process can efficiently differentiate MSCs into functional motor neurons that can be used for autologous nervous system therapy and especially for treating spinal cord injuries. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

The classification of explosion-proof protected induction motor into adequate temperature and efficiency class

NASA Astrophysics Data System (ADS)

Brinovar, Iztok; Srpčič, Gregor; Seme, Sebastijan; Štumberger, Bojan; Hadžiselimović, Miralem

2017-07-01

This article deals with the classification of explosion-proof protected induction motors, which are used in hazardous areas, into adequate temperature and efficiency class. Hazardous areas are defined as locations with a potentially explosive atmosphere where explosion may occur due to present of flammable gasses, liquids or combustible dusts (industrial plants, mines, etc.). Electric motors and electrical equipment used in such locations must be specially designed and tested to prevent electrical initiation of explosion due to high surface temperature and arcing contacts. This article presents the basic tests of three-phase explosion-proof protected induction motor with special emphasis on the measuring system and temperature rise test. All the measurements were performed with high-accuracy instrumentation and accessory equipment and carried out at the Institute of energy technology in the Electric machines and drives laboratory and Applied electrical engineering laboratory.

State reference design and saturated control of doubly-fed induction generators under voltage dips

NASA Astrophysics Data System (ADS)

Tilli, Andrea; Conficoni, Christian; Hashemi, Ahmad

2017-04-01

In this paper, the stator/rotor currents control problem of doubly-fed induction generator under faulty line voltage is carried out. Common grid faults cause a steep decline in the line voltage profile, commonly denoted as voltage dip. This point is critical for such kind of machines, having their stator windings directly connected to the grid. In this respect, solid methodological nonlinear control theory arguments are exploited and applied to design a novel controller, whose main goal is to improve the system behaviour during voltage dips, endowing it with low voltage ride through capability, a fundamental feature required by modern Grid Codes. The proposed solution exploits both feedforward and feedback actions. The feedforward part relies on suitable reference trajectories for the system internal dynamics, which are designed to prevent large oscillations in the rotor currents and command voltages, excited by line perturbations. The feedback part uses state measurements and is designed according to Linear Matrix Inequalities (LMI) based saturated control techniques to further reduce oscillations, while explicitly accounting for the system constraints. Numerical simulations verify the benefits of the internal dynamics trajectory planning, and the saturated state feedback action, in crucially improving the Doubly-Fed Induction Machine response under severe grid faults.

Sensorless Load Torque Estimation and Passivity Based Control of Buck Converter Fed DC Motor

PubMed Central

Kumar, S. Ganesh; Thilagar, S. Hosimin

2015-01-01

Passivity based control of DC motor in sensorless configuration is proposed in this paper. Exact tracking error dynamics passive output feedback control is used for stabilizing the speed of Buck converter fed DC motor under various load torques such as constant type, fan type, propeller type, and unknown load torques. Under load conditions, sensorless online algebraic approach is proposed, and it is compared with sensorless reduced order observer approach. The former produces better response in estimating the load torque. Sensitivity analysis is also performed to select the appropriate control variables. Simulation and experimental results fully confirm the superiority of the proposed approach suggested in this paper. PMID:25893208

Numerical calculation of primary slot leakage inductance of a Single-sided HTS linear induction motor used for linear metro

NASA Astrophysics Data System (ADS)

Li, Dong; Wen, Yinghong; Li, Weili; Fang, Jin; Cao, Junci; Zhang, Xiaochen; Lv, Gang

2017-03-01

In the paper, the numerical method calculating asymmetric primary slot leakage inductances of Single-sided High-Temperature Superconducting (HTS) Linear Induction Motor (HTS LIM) is presented. The mathematical and geometric models of three-dimensional nonlinear transient electromagnetic field are established and the boundary conditions are also given. The established model is solved by time-stepping Finite Element Method (FEM). Then, the three-phase asymmetric primary slot leakage inductances under different operation conditions are calculated by using the obtained electromagnetic field distribution. The influences of the special effects such as longitudinal end effects, transversal edge effects, etc. on the primary slot leakage inductance are investigated. The presented numerical method is validated by experiments carried out on a 3.5 kW prototype with copper wires which has the same structures with the HTS LIM.

Sherrington's Model of Successive Induction for Comparative Analysis of Zebrafish Motor Response

EPA Science Inventory

The responses in motor activity of zebrafish to sudden changes in lighting conditions may be modeled by Sherrington’s model of successive induction. Fish left in the dark exhibit very little motion, when exposed to light zebrafish motion increases towards an apparent horizo...

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

2015-06-29

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.

Neurogenic differentiation of dental pulp stem cells to neuron-like cells in dopaminergic and motor neuronal inductive media.

PubMed

Chang, Chia-Chieh; Chang, Kai-Chun; Tsai, Shang-Jye; Chang, Hao-Hueng; Lin, Chun-Pin

2014-12-01

Dental pulp stem cells (DPSCs) have been proposed as a promising source of stem cells in nerve regeneration due to their close embryonic origin and ease of harvest. The aim of this study was to evaluate the efficacy of dopaminergic and motor neuronal inductive media on transdifferentiation of human DPSCs (hDPSCs) into neuron-like cells. Isolation, cultivation, and identification of hDPSCs were performed with morphological analyses and flow cytometry. The proliferation potential of DPSCs was evaluated with an XTT [(2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide)] assay. Media for the induction of dopaminergic and spinal motor neuronal differentiation were prepared. The efficacy of neural induction was evaluated by detecting the expression of neuron cell-specific cell markers in DPSCs by immunocytochemistry and quantitative real-time reverse transcription polymerase chain reaction (RT-PCR). In the XTT assay, there was a 2.6- or 2-fold decrease in DPSCs cultured in dopaminergic or motor neuronal inductive media, respectively. The proportions of βIII-tubulin (βIII-tub), glial fibrillary acidic protein (GFAP), and oligodendrocyte (O1)-positive cells were significantly higher in DPSCs cultured in both neuronal inductive media compared with those cultured in control media. Furthermore, hDPSC-derived dopaminergic and spinal motor neuron cells after induction expressed a higher density of neuron cell markers than those before induction. These findings suggest that in response to the neuronal inductive stimuli, a greater proportion of DPSCs stop proliferation and acquire a phenotype resembling mature neurons. Such neural crest-derived adult DPSCs may provide an alternative stem cell source for therapy-based treatments of neuronal disorders and injury. Copyright © 2014. Published by Elsevier B.V.

Direct Torque Control of a Three-Phase Voltage Source Inverter-Fed Induction Machine

DTIC Science & Technology

2013-12-01

factors, FOC acquires all advantages of DC machine control and frees itself from the mechanical commutation drawbacks. Furthermore, FOC leads to high...of three-phase induction motor using microcontroller,” S.R.M Engineering College, Tamil Nadu, India , June/July 2006. [5] Texas Instruments Europe...loop. Direct flux control is possible through the constant magnetic field orientation achieved through commutator action. These two primary factors

Various Indices for Diagnosis of Air-gap Eccentricity Fault in Induction Motor-A Review

NASA Astrophysics Data System (ADS)

Nikhil; Mathew, Lini, Dr.; Sharma, Amandeep

2018-03-01

From the past few years, research has gained an ardent pace in the field of fault detection and diagnosis in induction motors. In the current scenario, software is being introduced with diagnostic features to improve stability and reliability in fault diagnostic techniques. Human involvement in decision making for fault detection is slowly being replaced by Artificial Intelligence techniques. In this paper, a brief introduction of eccentricity fault is presented along with their causes and effects on the health of induction motors. Various indices used to detect eccentricity are being introduced along with their boundary conditions and their future scope of research. At last, merits and demerits of all indices are discussed and a comparison is made between them.

Development of a linear induction motor based artificial muscle system.

PubMed

Gruber, A; Arguello, E; Silva, R

2013-01-01

We present the design of a linear induction motor based on electromagnetic interactions. The engine is capable of producing a linear movement from electricity. The design consists of stators arranged in parallel, which produce a magnetic field sufficient to displace a plunger along its axial axis. Furthermore, the winding has a shell and cap of ferromagnetic material that amplifies the magnetic field. This produces a force along the length of the motor that is similar to that of skeletal muscle. In principle, the objective is to use the engine in the development of an artificial muscle system for prosthetic applications, but it could have multiple applications, not only in the medical field, but in other industries.

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

Dynamic Average-Value Modeling of Doubly-Fed Induction Generator Wind Energy Conversion Systems

NASA Astrophysics Data System (ADS)

Shahab, Azin

In a Doubly-fed Induction Generator (DFIG) wind energy conversion system, the rotor of a wound rotor induction generator is connected to the grid via a partial scale ac/ac power electronic converter which controls the rotor frequency and speed. In this research, detailed models of the DFIG wind energy conversion system with Sinusoidal Pulse-Width Modulation (SPWM) scheme and Optimal Pulse-Width Modulation (OPWM) scheme for the power electronic converter are developed in detail in PSCAD/EMTDC. As the computer simulation using the detailed models tends to be computationally extensive, time consuming and even sometimes not practical in terms of speed, two modified approaches (switching-function modeling and average-value modeling) are proposed to reduce the simulation execution time. The results demonstrate that the two proposed approaches reduce the simulation execution time while the simulation results remain close to those obtained using the detailed model simulation.

Effect of Frequency and Spatial-Harmonics on Rotary and Linear Induction Motor Characteristics

DOT National Transportation Integrated Search

1972-03-01

A computer analysis is made of the effect of current and MMF airgap harmonics on the output characteristics of rotary and linear induction motors. The current harmonics accompanying thyristor-control operation are evaluated by Fourier analyzing the p...

Experimental setup for the measurement of induction motor cage currents

NASA Astrophysics Data System (ADS)

Bottauscio, Oriano; Chiampi, Mario; Donadio, Lorenzo; Zucca, Mauro

2005-04-01

An experimental setup for measurement of the currents flowing in the rotor bars of induction motors during synchronous no-load tests is described in the paper. The experimental verification of the high-frequency phenomena in the rotor cage is fundamental for a deep insight of the additional loss estimation by numerical methods. The attention is mainly focused on the analysis and design of the transducers developed for the cage current measurement.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hatakeyma, S., E-mail: hatakeyama.shoichi@torus.nr.titech.ac.jp; Yoshino, F.; Tsutsui, H.

2016-04-15

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).

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).

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.

Fast and accurate spectral estimation for online detection of partial broken bar in induction motors

NASA Astrophysics Data System (ADS)

Samanta, Anik Kumar; Naha, Arunava; Routray, Aurobinda; Deb, Alok Kanti

2018-01-01

In this paper, an online and real-time system is presented for detecting partial broken rotor bar (BRB) of inverter-fed squirrel cage induction motors under light load condition. This system with minor modifications can detect any fault that affects the stator current. A fast and accurate spectral estimator based on the theory of Rayleigh quotient is proposed for detecting the spectral signature of BRB. The proposed spectral estimator can precisely determine the relative amplitude of fault sidebands and has low complexity compared to available high-resolution subspace-based spectral estimators. Detection of low-amplitude fault components has been improved by removing the high-amplitude fundamental frequency using an extended-Kalman based signal conditioner. Slip is estimated from the stator current spectrum for accurate localization of the fault component. Complexity and cost of sensors are minimal as only a single-phase stator current is required. The hardware implementation has been carried out on an Intel i7 based embedded target ported through the Simulink Real-Time. Evaluation of threshold and detectability of faults with different conditions of load and fault severity are carried out with empirical cumulative distribution function.

About the Power Generation Confirmation of the Induction Motor and the Influence on the Islanding Detection Device

NASA Astrophysics Data System (ADS)

Igarashi, Hironobu; Sato, Takashi; Miyamoto, Kazunori; Kurokawa, Kousuke

The photovoltaic generation system must have protection device and islanding detection devices to connect with utility line of the electric power company. It is regulated in the technological requirement guideline and the electric equipment technology standard that the country provides. The islanding detection device detected purpose install for blackout due to the accident occurrence of the earth fault and the short-circuit in the utility line. When the islanding detection device detects the power blackout, it is necessary to stop the photovoltaic generation system immediately. If the photovoltaic generation system is not stopped immediately, electricity comes to charge the utility power line very at risk. We had already known that the islanding detection device can't detect the islanding phenomenon, if is there the induction motor in the loads. Authors decided to investigate the influence that the induction motors gave to the islanding detection device. The result was the load condition that the induction motors changed generator the voltage is restraining. Moreover, it was clarified that the time of the islanding was long compared with the load condition of not changing into the state of the generator. The value changes into the reactance of the induction motors according to the frequency change after the supply of electric power line stops. The frequency after the supply of electric power line stops changes for the unbalance the reactive power by the effect of the power rate constancy control with PLL of the power conditioner. However, the induction motors is also to the changing frequency, makes amends for the amount of reactive power, and the change in the frequency after the supply of electric power line stops as a result is controlled. When the frequency changed after the supply of electric power line stopped, it was clarified of the action on the direction where it made amends from the change of the constant for the amount of an invalid electric power, and

Simulation of three-phase induction motor drives using indirect field oriented control in PSIM environment

NASA Astrophysics Data System (ADS)

Aziri, Hasif; Patakor, Fizatul Aini; Sulaiman, Marizan; Salleh, Zulhisyam

2017-09-01

This paper presents the simulation of three-phase induction motor drives using Indirect Field Oriented Control (IFOC) in PSIM environment. The asynchronous machine is well known about natural limitations fact of highly nonlinearity and complexity of motor model. In order to resolve these problems, the IFOC is applied to control the instantaneous electrical quantities such as torque and flux component. As FOC is controlling the stator current that represented by a vector, the torque component is aligned with d coordinate while the flux component is aligned with q coordinate. There are five levels of the incremental system are gradually built up to verify and testing the software module in the system. Indeed, all of system build levels are verified and successfully tested in PSIM environment. Moreover, the corresponding system of five build levels are simulated in PSIM environment which is user-friendly for simulation studies in order to explore the performance of speed responses based on IFOC algorithm for three-phase induction motor drives.

CFAVC scheme for high frequency series resonant inverter-fed domestic induction heating system

NASA Astrophysics Data System (ADS)

Nagarajan, Booma; Reddy Sathi, Rama

2016-01-01

This article presents the investigations on the constant frequency asymmetric voltage cancellation control in the AC-AC resonant converter-fed domestic induction heating system. Conventional fixed frequency control techniques used in the high frequency converters lead to non-zero voltage switching operation and reduced output power. The proposed control technique produces higher output power than the conventional fixed-frequency control strategies. In this control technique, zero-voltage-switching operation is maintained during different duty cycle operation for reduction in the switching losses. Complete analysis of the induction heating power supply system with asymmetric voltage cancellation control is discussed in this article. Simulation and experimental study on constant frequency asymmetric voltage cancellation (CFAVC)-controlled full bridge series resonant inverter is performed. Time domain simulation results for the open and closed loop of the system are obtained using MATLAB simulation tool. The simulation results prove the control of voltage and power in a wide range. PID controller-based closed loop control system achieves the voltage regulation of the proposed system for the step change in load. Hardware implementation of the system under CFAVC control is done using the embedded controller. The simulation and experimental results validate the performance of the CFAVC control technique for series resonant-based induction cooking system.

Modeling and Demonstrating Regenerative Braking of a Squirrel Cage Induction Motor with Various Deceleration Rates Using V by F Control

DTIC Science & Technology

2010-06-01

DEMONSTRATING REGENERATIVE BRAKING OF A SQUIRREL CAGE INDUCTION MOTOR WITH VARIOUS DECELERATION RATES USING V BY F CONTROL by Billy J. Nytko...Regenerative Braking of a Squirrel Cage Induction Motor with Various Deceleration Rates Using V by F Control 6. AUTHOR(S) Billy J. Nytko 5. FUNDING...Naval Postgraduate School (NPS) to model regenerative braking to support energy conservation technologies and to improve the efficiencies within the

The chording effect on core losses of three-phase induction motor under sinusoidal and PWM voltage supplies

NASA Astrophysics Data System (ADS)

Deshmukh, Ram; Moses, A. J.; Anayi, F.

The core losses and the lower-order voltage harmonics of four different chorded motors fed from sinusoidal supply and inverter voltage supply were invigilated at no-load condition. All the four motors were tested with 4, 8 and 16 kHz switching frequencies and 30, 40, 50 and 60 Hz modulation frequencies The motor with 120° coil pitch has the least core losses and the lower-order voltage harmonics under sinusoidal and pulse width modulation (PWM) voltage supplies at all switching and modulation frequencies. The drop in the core losses for this motor was 46% and 53% under sinusoidal and PWM voltage supplies, respectively. The motor with 120° coil pitch is recommended to be used under sinusoidal and PWM voltage supplies.

A linear induction motor with a coated conductor superconducting secondary

NASA Astrophysics Data System (ADS)

Chen, Xin; Zheng, Shijun; Li, Jing; Ma, Guang Tong; Yen, Fei

2018-07-01

A linear induction motor system composed of a high-Tc superconducting secondary with close-ended coils made of REBCO coated conductor wire was designed and tested experimentally. The measured thrust, normal force and power loss are presented and explained by combining the flux dynamics inside superconductors with existing linear drive theory. It is found that an inherent capacitive component associated to the flux motion of vortices in the Type-II superconductor reduces the impedance of the coils; from such, the associated Lorentz forces are drastically increased. The resulting breakout thrust of the designed linear motor system was found to be extremely high (up to 4.7 kN/m2) while the associated normal forces only a fraction of the thrust. Compared to its conventional counterparts, high-Tc superconducting secondaries appear to be more feasible for use in maglev propulsion and electromagnetic launchers.

Speed control of an induction motor by 6-switched 3-level inverter

NASA Astrophysics Data System (ADS)

Saygin, Ali; Kerem, Alper

2017-12-01

This paper presents speed control analysis of an induction motor by a 6-switched 3-level inverter. In the analysis of topology, the study used the field oriented control technique which is widely used in the literature, easy and stable for operating systems. The field weaking technique was used for speeds exceeding nominal speed to reduce magnetic saturation and thermal losses. At the end of the process, it was observed to increase motor torque and inverter efficiency. Instead of using 12 switches in conventional 3-level inverters, 6 switches are used in this topology. Reduced number of switches is the greatest contribution of this study.

Condition monitoring of a wind turbine doubly-fed induction generator through current signature analysis

NASA Astrophysics Data System (ADS)

Artigao, Estefania; Honrubia-Escribano, Andres; Gomez-Lazaro, Emilio

2017-11-01

Operation and maintenance (O&M) of wind turbines is recently becoming the spotlight in the wind energy sector. While wind turbine power capacities continue to increase and new offshore developments are being installed, O&M costs keep raising. With the objective of reducing such costs, the new trends are moving from corrective and preventive maintenance toward predictive actions. In this scenario, condition monitoring (CM) has been identified as the key to achieve this goal. The induction generator of a wind turbine is a major contributor to failure rates and downtime where doubly-fed induction generators (DFIG) are the dominant technology employed in variable speed wind turbines. The current work presents the analysis of an in-service DFIG. A one-year measurement campaign has been used to perform the study. Several signal processing techniques have been applied and the optimal method for CM has been identified. A diagnosis has been reached, the DFIG under study shows potential gearbox damage.

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.

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.

Sensorless Modeling of Varying Pulse Width Modulator Resolutions in Three-Phase Induction Motors

PubMed Central

Marko, Matthew David; Shevach, Glenn

2017-01-01

A sensorless algorithm was developed to predict rotor speeds in an electric three-phase induction motor. This sensorless model requires a measurement of the stator currents and voltages, and the rotor speed is predicted accurately without any mechanical measurement of the rotor speed. A model of an electric vehicle undergoing acceleration was built, and the sensorless prediction of the simulation rotor speed was determined to be robust even in the presence of fluctuating motor parameters and significant sensor errors. Studies were conducted for varying pulse width modulator resolutions, and the sensorless model was accurate for all resolutions of sinusoidal voltage functions. PMID:28076418

Sensorless Modeling of Varying Pulse Width Modulator Resolutions in Three-Phase Induction Motors.

PubMed

Marko, Matthew David; Shevach, Glenn

2017-01-01

A sensorless algorithm was developed to predict rotor speeds in an electric three-phase induction motor. This sensorless model requires a measurement of the stator currents and voltages, and the rotor speed is predicted accurately without any mechanical measurement of the rotor speed. A model of an electric vehicle undergoing acceleration was built, and the sensorless prediction of the simulation rotor speed was determined to be robust even in the presence of fluctuating motor parameters and significant sensor errors. Studies were conducted for varying pulse width modulator resolutions, and the sensorless model was accurate for all resolutions of sinusoidal voltage functions.

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). © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

NASTRAN buckling study of a linear induction motor reaction rail

NASA Technical Reports Server (NTRS)

Williams, J. G.

1973-01-01

NASTRAN was used to study problems associated with the installation of a linear induction motor reaction rail test track. Specific problems studied include determination of the critical axial compressive buckling stress and establishment of the lateral stiffness of the reaction rail under combined loads. NASTRAN results were compared with experimentally obtained values and satisfactory agreement was obtained. The reaction rail was found to buckle at an axial compressive stress of 11,400 pounds per square inch. The results of this investigation were used to select procedures for installation of the reaction rail.

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.

Analysis of the mechanical stresses on a squirrel cage induction motor by the finite element method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jun, C.H.; Nicolas, A.

1999-05-01

The mechanical deformations and stresses have been analyzed by the Finite Element Method (FEM) in 3 dimensions on the rotor bars of a small squirrel cage induction motor. The authors considered the magnetic forces and the centrifugal forces as sources which provoked the deformations and stresses on the rotor bars. The mechanical calculations have been performed after doing the electromagnetic Finite Element modeling on the motor in steady states with various slip conditions.

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. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

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.

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.

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.

Infrared thermography based diagnosis of inter-turn fault and cooling system failure in three phase induction motor

NASA Astrophysics Data System (ADS)

Singh, Gurmeet; Naikan, V. N. A.

2017-12-01

Thermography has been widely used as a technique for anomaly detection in induction motors. International Electrical Testing Association (NETA) proposed guidelines for thermographic inspection of electrical systems and rotating equipment. These guidelines help in anomaly detection and estimating its severity. However, it focus only on location of hotspot rather than diagnosing the fault. This paper addresses two such faults i.e. inter-turn fault and failure of cooling system, where both results in increase of stator temperature. Present paper proposes two thermal profile indicators using thermal analysis of IRT images. These indicators are in compliance with NETA standard. These indicators help in correctly diagnosing inter-turn fault and failure of cooling system. The work has been experimentally validated for healthy and with seeded faults scenarios of induction motors.

Methodology for fault detection in induction motors via sound and vibration signals

NASA Astrophysics Data System (ADS)

Delgado-Arredondo, Paulo Antonio; Morinigo-Sotelo, Daniel; Osornio-Rios, Roque Alfredo; Avina-Cervantes, Juan Gabriel; Rostro-Gonzalez, Horacio; Romero-Troncoso, Rene de Jesus

2017-01-01

Nowadays, timely maintenance of electric motors is vital to keep up the complex processes of industrial production. There are currently a variety of methodologies for fault diagnosis. Usually, the diagnosis is performed by analyzing current signals at a steady-state motor operation or during a start-up transient. This method is known as motor current signature analysis, which identifies frequencies associated with faults in the frequency domain or by the time-frequency decomposition of the current signals. Fault identification may also be possible by analyzing acoustic sound and vibration signals, which is useful because sometimes this information is the only available. The contribution of this work is a methodology for detecting faults in induction motors in steady-state operation based on the analysis of acoustic sound and vibration signals. This proposed approach uses the Complete Ensemble Empirical Mode Decomposition for decomposing the signal into several intrinsic mode functions. Subsequently, the frequency marginal of the Gabor representation is calculated to obtain the spectral content of the IMF in the frequency domain. This proposal provides good fault detectability results compared to other published works in addition to the identification of more frequencies associated with the faults. The faults diagnosed in this work are two broken rotor bars, mechanical unbalance and bearing defects.

Solar fed DC-DC single ended primary inductance converter for low power applications

NASA Astrophysics Data System (ADS)

Narendranath, K. V.; Viswanath, Y.; Babu, K. Suresh; Arunkumar, G.; Elangovan, D.

2017-11-01

This paper presents 34 to 36 volts. SEPIC converter for solar fed applications. Now days, there has been tremendous increase in the usage of solar energy and this solar energy is most valuable energy source available all around the world. The solar energy system require a Dc-Dc converter in order to modulate and govern the changing output of the panel. In this paper, a system comprising of Single Ended Primary Inductance Converter [SEPIC] integrated with solar panel is proposed. This paper proposes SEPIC power converter design that will secure high performance and cost efficiency while powering up a LAMP load. This power converter designed with low output ripple voltage, higher efficiency and less electrical pressure on the power switching elements. The simulation and prototype hardware results are presented in this paper.

An Improved Power Quality Based Sheppard-Taylor Converter Fed BLDC Motor Drive

NASA Astrophysics Data System (ADS)

Singh, Bhim; Bist, Vashist

2015-12-01

This paper deals with the design and analysis of a power factor correction based Sheppard-Taylor converter fed brushless dc motor (BLDCM) drive. The speed of the BLDCM is controlled by adjusting the dc link voltage of the voltage source inverter (VSI) feeding BLDCM. Moreover, a low frequency switching of the VSI is used for electronically commutating the BLDCM for reduced switching losses. The Sheppard-Taylor converter is designed to operate in continuous conduction mode to achieve an improved power quality at the ac mains for a wide range of speed control and supply voltage variation. The BLDCM drive is designed and its performance is simulated in a MATLAB/Simulink environment to achieve the power quality indices within the limits of the international power quality standard IEC-61000-3-2.

Stable Adaptive Inertial Control of a Doubly-Fed Induction Generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Moses; Muljadi, Eduard; Hur, Kyeon

2016-11-01

This paper proposes a stable adaptive inertial control scheme of a doubly-fed induction generator. The proposed power reference is defined in two sections: the deceleration period and the acceleration period. The power reference in the deceleration period consists of a constant and the reference for maximum power point tracking (MPPT) operation. The latter contributes to preventing a second frequency dip (SFD) in this period because its reduction rate is large at the early stage of an event but quickly decreases with time. To improve the frequency nadir (FN), the constant value is set to be proportional to the rotor speedmore » prior to an event. The reference ensures that the rotor speed converges to a stable operating region. To accelerate the rotor speed while causing a small SFD, when the rotor speed converges, the power reference is reduced by a small amount and maintained until it meets the MPPT reference. The results show that the scheme causes a small SFD while improving the FN and the rate of change of frequency in any wind conditions, even in a grid that has a high penetration of wind power.« less

Punching influence on magnetic properties of the stator teeth of an induction motor

NASA Astrophysics Data System (ADS)

Kedous-Lebouc, A.; Cornut, B.; Perrier, J. C.; Manfé, Ph.; Chevalier, Th.

2003-01-01

In order to study the effects of punching of electrical steel sheets, a suitable geometrical structure able to characterize the stator teeth behavior of an induction motor is proposed and validated. The influence of the punching on a fully processed M330-65A is then characterized. A spectacular degradation of loss and B( H) curves is observed. This leads to a perceptible increase of the no-load machine current.

Mesodermal and neuronal retinoids regulate the induction and maintenance of limb innervating spinal motor neurons.

PubMed

Ji, Sheng-Jian; Zhuang, BinQuan; Falco, Crystal; Schneider, André; Schuster-Gossler, Karin; Gossler, Achim; Sockanathan, Shanthini

2006-09-01

During embryonic development, the generation, diversification and maintenance of spinal motor neurons depend upon extrinsic signals that are tightly regulated. Retinoic acid (RA) is necessary for specifying the fates of forelimb-innervating motor neurons of the Lateral Motor Column (LMC), and the specification of LMC neurons into medial and lateral subtypes. Previous studies implicate motor neurons as the relevant source of RA for specifying lateral LMC fates at forelimb levels. However, at the time of LMC diversification, a significant amount of retinoids in the spinal cord originates from the adjacent paraxial mesoderm. Here we employ mouse genetics to show that RA derived from the paraxial mesoderm is required for lateral LMC induction at forelimb and hindlimb levels, demonstrating that mesodermally synthesized RA functions as a second source of signals to specify lateral LMC identity. Furthermore, reduced RA levels in postmitotic motor neurons result in a decrease of medial and lateral LMC neurons, and abnormal axonal projections in the limb; invoking additional roles for neuronally synthesized RA in motor neuron maintenance and survival. These findings suggest that during embryogenesis, mesodermal and neuronal retinoids act coordinately to establish and maintain appropriate cohorts of spinal motor neurons that innervate target muscles in the limb.

Hybrid renewable energy system using doubly-fed induction generator and multilevel inverter

NASA Astrophysics Data System (ADS)

Ahmed, Eshita

The proposed hybrid system generates AC power by combining solar and wind energy converted by a doubly-fed induction generator (DFIG). The DFIG, driven by a wind turbine, needs rotor excitation so the stator can supply a load or the grid. In a variable-speed wind energy system, the stator voltage and its frequency vary with wind speed, and in order to keep them constant, variable-voltage and variable-frequency rotor excitation is to be provided. A power conversion unit supplies the rotor, drawing power either from AC mains or from a PV panel depending on their availability. It consists of a multilevel inverter which gives lower harmonic distortion in the stator voltage. Maximum power point tracking techniques have been implemented for both wind and solar power. The complete hybrid renewable energy system is implemented in a PSIM-Simulink interface and the wind energy conversion portion is realized in hardware using dSPACE controller board.

Induction of Parkinson disease-related proteins in motor neurons after transient spinal cord ischemia in rabbits.

PubMed

Sakurai, Masahiro; Kawamura, Takae; Nishimura, Hidekazu; Suzuki, Hiroyoshi; Tezuka, Fumiaki; Abe, Koji

2009-04-01

The mechanism of spinal cord injury has been thought to be related to the vulnerability of spinal motor neuron cells against ischemia. However, the mechanisms of such vulnerability are not fully understood. We investigated a possible mechanism of neuronal death by immunohistochemical analysis for DJ-1, PINK1, and alpha-Synuclein. We used a 15-min rabbit spinal cord ischemia model, with use of a balloon catheter. Western blot analysis for DJ-1, PINK1, and alpha-Synuclein; temporal profiles of DJ-1, PINK1, and alpha-Synuclein immunoreactivity; and double-label fluorescence immunocytochemical studies were performed. Western blot analysis revealed scarce immunoreactivity for DJ-1, PINK1, and alpha-Synuclein in the sham-operated spinal cords. However, they became apparent at 8 h after transient ischemia, which returned to the baseline level at 1 day. Double-label fluorescence immunocytochemical study revealed that both DJ-1 and PINK1, and DJ-1 and alpha-Synuclein were positive at 8 h of reperfusion in the same motor neurons, which eventually die. The induction of DJ-1 and PINK1 proteins in the motor neurons at the early stage of reperfusion may indicate oxidative stress, and the induction of alpha-Synuclein may be implicated in the programmed cell death change after transient spinal cord ischemia.

Introduction to IEEE 841-1994, IEEE standard for petroleum and chemical industry: Severe duty totally enclosed fan-cooled (TEFC) squirrel cage induction motors -- up to and including 500 hp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Doughty, R.L.

1995-12-31

IEEE 841, Recommended Practice for Chemical Industry Severe Duty Squirrel-Cage Induction Motors--600 V and Below, first issued in 1986, has been significantly revised and reissued as a Standard. The scope has been increased to include severe duty TEFC squirrel-cage induction motors with antifriction bearings in sizes up to and including 500 horsepower. Motor rated voltages of 2,300 V and 4,000 V have been added. Changes to the standard are reviewed in detail. Requirements are identified that improve motor reliability and increase motor life.

PI controller design for indirect vector controlled induction motor: A decoupling approach.

PubMed

Jain, Jitendra Kr; Ghosh, Sandip; Maity, Somnath; Dworak, Pawel

2017-09-01

Decoupling of the stator currents is important for smoother torque response of indirect vector controlled induction motors. Typically, feedforward decoupling is used to take care of current coupling that requires exact knowledge of motor parameters, additional circuitry and signal processing. In this paper, a method is proposed to design the regulating proportional-integral gains that minimize coupling without any requirement of the additional decoupler. The variation of the coupling terms for change in load torque is considered as the performance measure. An iterative linear matrix inequality based H ∞ control design approach is used to obtain the controller gains. A comparison between the feedforward and the proposed decoupling schemes is presented through simulation and experimental results. The results show that the proposed scheme is simple yet effective even without additional block or burden on signal processing. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

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

PubMed

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.

Grid-connected in-stream hydroelectric generation based on the doubly fed induction machine

NASA Astrophysics Data System (ADS)

Lenberg, Timothy J.

Within the United States, there is a growing demand for new environmentally friendly power generation. This has led to a surge in wind turbine development. Unfortunately, wind is not a stable prime mover, but water is. Why not apply the advances made for wind to in-stream hydroelectric generation? One important advancement is the creation of the Doubly Fed Induction Machine (DFIM). This thesis covers the application of a gearless DFIM topology for hydrokinetic generation. After providing background, this thesis presents many of the options available for the mechanical portion of the design. A mechanical turbine is then specified. Next, a method is presented for designing a DFIM including the actual design for this application. In Chapter 4, a simulation model of the system is presented, complete with a control system that maximizes power generation based on water speed. This section then goes on to present simulation results demonstrating proper operation.

Induction of human umbilical Wharton's jelly-derived mesenchymal stem cells toward motor neuron-like cells.

PubMed

Bagher, Zohreh; Ebrahimi-Barough, Somayeh; Azami, Mahmoud; Mirzadeh, Hamid; Soleimani, Mansooreh; Ai, Jafar; Nourani, Mohammad Reza; Joghataei, Mohammad Taghi

2015-10-01

The most important property of stem cells from different sources is the capacity to differentiate into various cells and tissue types. However, problems including contamination, normal karyotype, and ethical issues cause many limitations in obtaining and using these cells from different sources. The cells in Wharton's jelly region of umbilical cord represent a pool source of primitive cells with properties of mesenchymal stem cells (MSCs). The aim of this study was to determine the potential of human Wharton's jelly-derived mesenchymal stem cells (WJMSCs) for differentiation to motor neuron cells. WJMSCs were induced to differentiate into motor neuron-like cells by using different signaling molecules and neurotrophic factors in vitro. Differentiated neurons were then characterized for expression of motor neuron markers including nestin, PAX6, NF-H, Islet 1, HB9, and choline acetyl transferase (ChAT) by quantitative reverse transcription PCR and immunocytochemistry. Our results showed that differentiated WJMSCs could significantly express motor neuron biomarkers in RNA and protein levels 15 d post induction. These results suggested that WJMSCs can differentiate to motor neuron-like cells and might provide a potential source in cell therapy for neurodegenerative disease.

Opposite optimal current flow directions for induction of neuroplasticity and excitation threshold in the human motor cortex.

PubMed

Sommer, Martin; Norden, Christoph; Schmack, Lars; Rothkegel, Holger; Lang, Nicolas; Paulus, Walter

2013-05-01

Directional sensitivity is relevant for the excitability threshold of the human primary motor cortex, but its importance for externally induced plasticity is unknown. To study the influence of current direction on two paradigms inducing neuroplasticity by repetitive transcranial magnetic stimulation (rTMS). We studied short-lasting after-effects induced in the human primary motor cortex of 8 healthy subjects, using 5 Hz rTMS applied in six blocks of 200 pulses each, at 90% active motor threshold. We controlled for intensity, frequency, waveform and spinal effects. Only biphasic pulses with the effective component delivered in an anterioposterior direction (henceforth posteriorly directed) in the brain yielded an increase of motor-evoked potential (MEP) amplitudes outlasting rTMS. MEP latencies and F-wave amplitudes remained unchanged. Biphasic pulses directed posteroanterior (i.e. anteriorly) were ineffective, as were monophasic pulses from either direction. A 1 Hz study in a group of 12 healthy subjects confirmed facilitation after posteriorly directed biphasic pulses only. The anisotropy of the human primary motor cortex is relevant for induction of plasticity by subtreshold rTMS, with a current flow opposite to that providing lowest excitability thresholds. This is consistent with the idea of TMS primarily targeting cortical columns of the phylogenetically new M1 in the anterior bank of the central sulcus. For these, anteriorly directed currents are soma-depolarizing, therefore optimal for low thresholds, whereas posteriorly directed currents are soma-hyperpolarizing, likely dendrite-depolarizing and bested suited for induction of plasticity. Our findings should help focus and enhance rTMS effects in experimental and clinical settings. Copyright © 2013 Elsevier Inc. All rights reserved.

Energy Efficiency of Induction Motors Running Off Frequency Converters with Pulse-Width Voltage Modulation{sup 1}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shvetsov, N. K., E-mail: elmash@em.ispu.ru

2016-11-15

The results of calculations of the increase in losses in an induction motor with frequency control and different forms of the supply voltage are presented. The calculations were performed by an analytic method based on harmonic analysis of the supply voltage as well as numerical calculation of the electromagnetic processes by the finite-element method.

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.

Permanent magnet motors

NASA Astrophysics Data System (ADS)

Richter, E.

1984-09-01

The work deals with the design and analysis study for the conceptual design of an economical high efficiency ac motor based on permanent magnets. The design and trade off studies have covered the material considerations, the design tradeoff options as well as transient and steady state performance considerations, and other options. The baseline comparison is the high efficiency induction motor. The permanent magnet (PM) motor must fit into the same frame size and surpass the induction motor on a life cost basis that includes 2.5 years of operation at a 50% duty cycle. It is shown that a motor based upon ferrite magnets does meet the objectives of the program in ratings of up to 25 hp. A 7.5 motor design is carried through the conceptual design stage.

A multi-train electrical stimulation protocol facilitates transcranial electrical motor evoked potentials and increases induction rate and reproducibility even in patients with preoperative neurological deficits.

PubMed

Ushio, Shuta; Kawabata, Shigenori; Sumiya, Satoshi; Kato, Tsuyoshi; Yoshii, Toshitaka; Yamada, Tsuyoshi; Enomoto, Mitsuhiro; Okawa, Atsushi

2018-06-01

This study sought to evaluate the facilitation effect of repetitive multi-train transcranial electrical stimulation (mt-TES) at 2 repetition rates on transcranial electrical motor evoked potential (Tc-MEP) monitoring during spinal surgery, and to assess the induction rate in patients with impaired motor function from a compromised spinal cord or spinal nerve. We studied 32 consecutive patients with impaired motor function undergoing cervical or thoracic spinal surgery (470 muscles). A series of 10 TESs with 5 pulse trains were preoperatively delivered at 2 repetition rates (1 and 5 Hz). All peak-topeak amplitudes of the MEPs of the upper and lower extremity muscles elicited by the 10 TESs were measured. The induction rates of the lower extremity muscles were also assessed with muscle and preoperative lower extremity motor function scores. In each of the muscles, MEP amplitudes were augmented by about 2-3 times at 1 Hz and 5-6 times at 5 Hz. Under the 5-Hz condition, all limb muscles showed significant amplification. Also, in all preoperative motor function score groups, the amplitudes and induction rates of the lower extremity muscles were significantly increased. Moreover, the facilitation effects tended to peak in the last half of the series of 10 TESs. In all score groups of patients with preoperative neurological deficits, repetitive mt-TES delivered at a frequency of 5 Hz markedly facilitated the MEPs of all limb muscles and increased the induction rate. We recommend this method to improve the reliability of intraoperative monitoring during spinal surgery.

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.

Power Smoothing and MPPT for Grid-connected Wind Power Generation with Doubly Fed Induction Generator

NASA Astrophysics Data System (ADS)

Kai, Takaaki; Tanaka, Yuji; Kaneda, Hirotoshi; Kobayashi, Daichi; Tanaka, Akio

Recently, doubly fed induction generator (DFIG) and synchronous generator are mostly applied for wind power generation, and variable speed control and power factor control are executed for high efficiently for wind energy capture and high quality for power system voltage. In variable speed control, a wind speed or a generator speed is used for maximum power point tracking. However, performances of a wind generation power fluctuation due to wind speed variation have not yet investigated for those controls. The authors discuss power smoothing by those controls for the DFIG inter-connected to 6.6kV distribution line. The performances are verified using power system simulation software PSCAD/EMTDC for actual wind speed data and are examined from an approximate equation of wind generation power fluctuation for wind speed variation.

Specific induction of Akt3 in spinal cord motor neurons is neuroprotective in a mouse model of familial amyotrophic lateral sclerosis.

PubMed

Peviani, Marco; Tortarolo, Massimo; Battaglia, Elisa; Piva, Roberto; Bendotti, Caterina

2014-02-01

Evidence is accumulating that an imbalance between pathways for degeneration or survival in motor neurons may play a central role in mechanisms that lead to neurodegeneration in amyotrophic lateral sclerosis (ALS). We and other groups have observed that downregulation, or lack of induction, of the PI3K/Akt prosurvival pathway may be responsible for defective response of motor neurons to injury and their consequent cellular demise. Some of the neuroprotective effects mediated by growth factors may involve activation of Akt, but a proof of concept of Akt as a target for therapy is lacking. We demonstrate that specific expression of constitutively activated Akt3 in motor neurons through the use of the promoter of homeobox gene Hb9 prevents neuronal loss induced by SOD1.G93A both in vitro (in mixed neuron/astrocyte cocultures) and in vivo (in a mouse model of ALS). Inhibition of ASK1 and GSK3beta was involved in the neuroprotective effects of activated Akt3, further supporting the hypothesis that induction of Akt3 may be a key step in activation of pathways for survival in the attempt to counteract motor neuronal degeneration in ALS.

Induction of lesions of selenium-vitamin E deficiency in pigs fed silver

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Vleet, J.F.

1976-12-01

Four weanling swine fed for 4 weeks a commercial ration adequate in selenium and vitamin E, but supplemented with 0.5% silver acetate, developed lesions typical of selenium-vitamin E deficiency. Clinically, the pigs fed this high level of silver had anorexia, diarrhea, and growth depression; 3 of 4 pigs died. At necropsy, hepatic lesions of hepatosis dietetica were present in 4 of 4 silver-fed pigs, and 1 of 4 pigs had cardiac and skeletal muscle lesions characteristic of selenium-vitamin E deficiency. Development of lesions and mortality was prevented in 2 pigs fed the silver diet supplemented with ..cap alpha..-tocopherol (100 IU/kgmore » of diet), but not in 2 pigs fed the ratio supplemented with selenium as selenite (1 ppm). Four pigs fed a lower dose level of silver (0.2% silver acetate) for 6 weeks failed to develop clinical or pathologic features of selenium-vitamin E deficiency. However, hepatic selenium content was significantly increased in pigs fed the silver-supplemented ration.« less

Specific induction of PAG608 in cranial and spinal motor neurons of L-DOPA-treated parkinsonian rats.

PubMed

Shimizu, Masako; Miyazaki, Ikuko; Higashi, Youichirou; Eslava-Alva, Maria J; Diaz-Corrales, Francisco J; Asanuma, Masato; Ogawa, Norio

2008-04-01

We identified p53-activated gene 608 (PAG608) as a specifically induced gene in striatal tissue of L-DOPA (100mg/kg)-injected hemi-parkinsonian rats using differential display assay. In the present study, we further examined morphological distribution of PAG608 in the central nervous system of L-DOPA-treated hemi-parkinsonian rats. PAG608 expression was markedly induced in fibers and neuronal cells of the lateral globus pallidus and reticular thalamic nucleus adjacent to internal capsule, specifically in the parkinsonian side of L-DOPA-treated models. The protein was also constitutively expressed in motor neurons specifically in either side of the pontine nucleus and motor nuclei of trigeminal and facial nerves. Furthermore, L-DOPA-induced PAG608 expression on motor neurons in the contralateral side of the ventral horn of the spinal cord and the lateral corticospinal tract without cell loss. The specific induction of PAG608 6-48h after L-DOPA injection in the extrapyramidal tracts, pyramidal tracts and corresponding lower motor neurons of the spinal cords suggests its involvement in molecular events in stimulated motor neurons. Taken together with the constitutive expression of PAG608 in the motor nuclei of cranial nerves, PAG608 may be a useful marker of stressed or activated lower motor neurons.

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.

Modeling and simulation of soft sensor design for real-time speed estimation, measurement and control of induction motor.

PubMed

Etien, Erik

2013-05-01

This paper deals with the design of a speed soft sensor for induction motor. The sensor is based on the physical model of the motor. Because the validation step highlight the fact that the sensor cannot be validated for all the operating points, the model is modified in order to obtain a fully validated sensor in the whole speed range. An original feature of the proposed approach is that the modified model is derived from stability analysis using automatic control theory. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

Dynamic Droop–Based Inertial Control of a Doubly-Fed Induction Generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, Min; Muljadi, Eduard; Park, Jung-Wook

2016-07-01

If a large disturbance occurs in a power grid, two auxiliary loops for the inertial control of a wind turbine generator have been used: droop loop and rate of change of frequency (ROCOF) loop. Because their gains are fixed, difficulties arise in determining them suitable for all grid and wind conditions. This paper proposes a dynamic droop-based inertial control scheme of a doubly-fed induction generator (DFIG). The scheme aims to improve the frequency nadir (FN) and ensure stable operation of a DFIG. To achieve the first goal, the scheme uses a droop loop, but it dynamically changes its gain basedmore » on the ROCOF to release a large amount of kinetic energy during the initial stage of a disturbance. To do this, a shaping function that relates the droop to the ROCOF is used. To achieve the second goal, different shaping functions, which depend on rotor speeds, are used to give a large contribution in high wind conditions and prevent over-deceleration in low wind conditions during inertial control. The performance of the proposed scheme was investigated under various wind conditions using an EMTP-RV simulator. The results indicate that the scheme improves the FN and ensures stable operation of a DFIG.« less

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.

Electromagnetic Performance Calculation of HTS Linear Induction Motor for Rail Systems

NASA Astrophysics Data System (ADS)

Liu, Bin; Fang, Jin; Cao, Junci; Chen, Jie; Shu, Hang; Sheng, Long

2017-07-01

According to a high temperature superconducting (HTS) linear induction motor (LIM) designed for rail systems, the influence of electromagnetic parameters and mechanical structure parameters on the electromagnetic horizontal thrust, vertical force of HTS LIM and the maximum vertical magnetic field of HTS windings are analyzed. Through the research on the vertical field of HTS windings, the development regularity of the HTS LIM maximum input current with different stator frequency and different thickness value of the secondary conductive plate is obtained. The theoretical results are of great significance to analyze the stability of HTS LIM. Finally, based on theory analysis, HTS LIM test platform was built and the experiment was carried out with load. The experimental results show that the theoretical analysis is correct and reasonable.

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.

A novel adaptive control method for induction motor based on Backstepping approach using dSpace DS 1104 control board

NASA Astrophysics Data System (ADS)

Ben Regaya, Chiheb; Farhani, Fethi; Zaafouri, Abderrahmen; Chaari, Abdelkader

2018-02-01

This paper presents a new adaptive Backstepping technique to handle the induction motor (IM) rotor resistance tracking problem. The proposed solution leads to improve the robustness of the control system. Given the presence of static error when estimating the rotor resistance with classical methods, and the sensitivity to the load torque variation at low speed, a new Backstepping observer enhanced with an integral action of the tracking errors is presented, which can be established in two steps. The first one consists to estimate the rotor flux using a Backstepping observer. The second step, defines the adaptation mechanism of the rotor resistance based on the estimated rotor-flux. The asymptotic stability of the observer is proven by Lyapunov theory. To validate the proposed solution, a simulation and experimental benchmarking of a 3 kW induction motor are presented and analyzed. The obtained results show the effectiveness of the proposed solution compared to the model reference adaptive system (MRAS) rotor resistance observer presented in other recent works.

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.

Reducing current reversal time in electric motor control

DOEpatents

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.

Hepatic microsomal cytochromes P450 in mink fed Saginaw Bay carp (SBC)

USGS Publications Warehouse

Melancon, M.J.; LeCaptain, L.; Rattner, B.A.; Heaton, S.; Aulerich, R.; Tillitt, D.; Stegeman, John J.; Woodin, B.

1992-01-01

Livers from mink fed diets containing 0% (n = 12), 10% (n = 11), 20% (n = 12) and 40% (n = 10) SBC for 6 months contained 0.1, 2.2, 3.6, and 6.3 ug/g total PCBs, respectively. Hepatic microsomes were prepared and assayed for protein, arylhydrocarbon hydroxylase (AHH), benzyloxyresorufin-O-dealkylase (BROD), ethoxy-ROD (ER0D), pentoxy-ROD (PROD), and ethoxycoumarin-OD (ECOD). Mink fed SBC had increased AHH, EROD, and ECOD (group means 2.2-3.4 X control means), decreased BROD and unchanged PROD (the latter 2 assays indicators for phenobarbital-type induction in mammals). Three samples from each group were examined by western blot using a polyclonal anti-P450llB antibody and a monoclonal anti-P450lA antibody (MAb 1-12-3). Mink fed SBC showed induction of a protein recognized by anti-P450lA (8 X control), but had little protein recognized by anti-P450IlB. The monooxygenase activities and western blot data give a consistent picture of MC-type but not PB-type induction in mink fed SBC.

Full-order observer for direct torque control of induction motor based on constant V/F control technique.

PubMed

Pimkumwong, Narongrit; Wang, Ming-Shyan

2018-02-01

This paper presents another control method for the three-phase induction motor that is direct torque control based on constant voltage per frequency control technique. This method uses the magnitude of stator flux and torque errors to generate the stator voltage and phase angle references for controlling the induction motor by using constant voltage per frequency control method. Instead of hysteresis comparators and optimum switching table, the PI controllers and space vector modulation technique are used to reduce torque and stator-flux ripples and achieve constant switching frequency. Moreover, the coordinate transformations are not required. To implement this control method, a full-order observer is used to estimate stator flux and overcome the problems from drift and saturation in using pure integrator. The feedback gains are designed by simple manner to improve the convergence of stator flux estimation, especially in low speed range. Furthermore, the necessary conditions to maintain the stability for feedback gain design are introduced. The simulation and experimental results show accurate and stable operation of the introduced estimator and good dynamic response of the proposed control method. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Modelling high frequency phenomena in the rotor of induction motors under no-load test conditions

NASA Astrophysics Data System (ADS)

Boglietti, Aldo; Bottauscio, Oriano; Chiampi, Mario; Lazzari, Mario

2003-01-01

The paper aims to deep the electromagnetic phenomena in the rotor of induction motors produced during the no-load test by the high-order harmonics of the spatial distribution of magnetic flux. The analysis is carried out by a flux driven finite element procedure, which can take into account the hysteresis of magnetic material, the induced currents in rotor cage and the eddy currents in the laminations. The computed results, including losses and local waveforms of electrical and magnetic quantities, are finally discussed.

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.

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. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Issues of Exploitation of Induction Motors in the Course of Underground Mining Operations

NASA Astrophysics Data System (ADS)

Gumula, Stanisław; Hudy, Wiktor; Piaskowska-Silarska, Malgorzata; Pytel, Krzysztof

2017-09-01

Mining industry is one of the most important customers of electric motors. The most commonly used in the contemporary mining industry is alternating current machines used for processing electrical energy into mechanical energy. The operating problems and the influence of qualitative interference acting on the inputs of individual regulators to field-oriented system in the course of underground mining operations has been presented in the publication. The object of controlling the speed is a slip-ring induction motor. Settings of regulators were calculated using an evolutionary algorithm. Examination of system dynamics was performed by a computer with the use of the MATLAB / Simulink software. According to analyzes, large distortion of input signals of regulators adversely affects the rotational speed that pursued by the control system, which may cause a large vibration of the whole system and, consequently, its much faster destruction. Designed system is characterized by a significantly better resistance to interference. The system is stable with the properly selected settings of regulators, which is particularly important during the operation of machinery used in underground mining.

Age-related changes in late I-waves influence motor cortex plasticity induction in older adults.

PubMed

Opie, George M; Cirillo, John; Semmler, John G

2018-04-18

The response to neuroplasticity interventions using transcranial magnetic stimulation (TMS) is reduced in older adults, which may be due, in part, to age-related alterations in interneuronal (I-wave) circuitry. The current study investigated age-related changes in interneuronal characteristics and whether they influence motor cortical plasticity in older adults. While I-wave recruitment was unaffected by age, there was a shift in the temporal characteristics of the late, but not early I-waves. Using I-wave periodicity repetitive TMS (iTMS), we showed that these differences in I-wave characteristics influence the induction of cortical plasticity in older adults. Previous research shows that neuroplasticity assessed using transcranial magnetic stimulation (TMS) is reduced in older adults. While this deficit is often assumed to represent altered synaptic modification processes, age-related changes in the interneuronal circuits activated by TMS may also contribute. Here we assessed age-related differences in the characteristics of the corticospinal indirect (I) waves and how they influence plasticity induction in primary motor cortex. Twenty young (23.7 ± 3.4 years) and 19 older adults (70.6 ± 6.0 years) participated in these studies. I-wave recruitment was assessed by changing the direction of the current used to activate the motor cortex, whereas short-interval intracortical facilitation (SICF) was recorded to assess facilitatory I-wave interactions. In a separate study, I-wave periodicity TMS (iTMS) was used to examine the effect of I-wave latency on motor cortex plasticity. Data from the motor evoked potential (MEP) onset latency produced using different coil orientations suggested that there were no age-related differences in preferential I-wave recruitment (P = 0.6). However, older adults demonstrated significant reductions in MEP facilitation at all 3 SICF peaks (all P-values < 0.05) and a delayed latency of the second and third SICF peaks (all P

API 541 Third Edition, a revised and improved purchasing specification for form wound squirrel cage induction motors -- 250 horsepower and larger

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donner, G.; Subler, W.

1995-12-31

API 541 Third Edition is a standard that covers the minimum requirements for all form wound squirrel cage induction motors above NEMA 440 frame sizes (normally 250 HP and above). The standard is intended to be used to describe motors that will be used by the petroleum industry. The purpose of API 541 is to serve as a comprehensive standard which can be used by specifiers of high performance motors. Users no longer have to prepare their own purchase specifications, and manufacturers can produce a standard motor that will be widely accepted and competitively priced. The API 541 Standard ismore » revised on a 5 year cycle to insure that it is always timely and reflects the latest technology.« less

HO-1 induction in motor cortex and intestinal dysfunction in TDP-43 A315T transgenic mice.

PubMed

Guo, Yansu; Wang, Qian; Zhang, Kunxi; An, Ting; Shi, Pengxiao; Li, Zhongyao; Duan, Weisong; Li, Chunyan

2012-06-15

TAR DNA-binding protein 43 (TDP-43) has been found to be related to the pathogenesis of amyotrophic lateral sclerosis (ALS). TDP-43 A315T transgenic mice develop degeneration of specific motor neurons, and accumulation of ubiquitinated proteins has been observed in the pyramidal cells of motor cortex of these mice. In this study, we found stress-responsive HO-1 induction and no autophagic alteration in motor cortex of TDP-43 A315T transgenic mice. Glial activation, especially astrocytic proliferation, occurred in cortical layer 5 and sub-meningeal region. Interestingly, we noticed that progressively thinned colon, swollen small intestine and reduced food intake, rather than severe muscle weakness, contributed to the death of TDP-43 A315T transgenic mice. Increased TDP-43 accumulation in the myenteric nerve plexus and increased thickness of muscular layer of colon were related to the intestinal dysfunction. Copyright © 2012 Elsevier B.V. All rights reserved.

A Novelty Design Of Minimization Of Electrical Losses In A Vector Controlled Induction Machine Drive

NASA Astrophysics Data System (ADS)

Aryza, Solly; Irwanto, M.; Lubis, Zulkarnain; Putera Utama Siahaan, Andysah; Rahim, Robbi; Furqan, Mhd.

2018-01-01

The induction motor has in the industry . More attention has been a focus to develop and design of induction motor drive. With the method of vector control novelty prove the efficiency of induction motor over their entire speed range. In this paper desirable to design a loss minimization controller which can improve the efficiency. Also, this research described Modeling of an induction motor with core loss included. Realization of methods vector control for an induction motor drive with loss element included. The case of the loss minimization condition. The procedure was successful to calculate the gains of a PI controller. Though the problem of obtaining a robust and sensorless induction motor drive is by no means completely solved, the results obtained as part of this work point in a promising direction.

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.

Detection of stator winding faults in induction motors using three-phase current monitoring.

PubMed

Sharifi, Rasool; Ebrahimi, Mohammad

2011-01-01

The objective of this paper is to propose a new method for the detection of inter-turn short circuits in the stator windings of induction motors. In the previous reported methods, the supply voltage unbalance was the major difficulty, and this was solved mostly based on the sequence component impedance or current which are difficult to implement. Some other methods essentially are included in the offline methods. The proposed method is based on the motor current signature analysis and utilizes three phase current spectra to overcome the mentioned problem. Simulation results indicate that under healthy conditions, the rotor slot harmonics have the same magnitude in three phase currents, while under even 1 turn (0.3%) short circuit condition they differ from each other. Although the magnitude of these harmonics depends on the level of unbalanced voltage, they have the same magnitude in three phases in these conditions. Experiments performed under various load, fault, and supply voltage conditions validate the simulation results and demonstrate the effectiveness of the proposed technique. It is shown that the detection of resistive slight short circuits, without sensitivity to supply voltage unbalance is possible. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

Composite synchronization of three eccentric rotors driven by induction motors in a vibrating system

NASA Astrophysics Data System (ADS)

Kong, Xiangxi; Chen, Changzheng; Wen, Bangchun

2018-03-01

This paper addresses the problem of composite synchronization of three eccentric rotors (ERs) driven by induction motors in a vibrating system. The composite synchronous motion of three ERs is composed of the controlled synchronous motion of two ERs and the self-synchronous motion of the third ER. Combining an adaptive sliding mode control (ASMC) algorithm with a modified master-slave control structure, the controllers are designed to implement controlled synchronous motion of two ERs with zero phase difference. Based on Lyapunov stability theorem and Barbalat's lemma, the stability of the designed controllers is verified. On basis of controlled synchronization of two ERs, self-synchronization of the third ER is introduced to implement composite synchronous motion of three ERs. The feasibility of the proposed composite synchronization method is analyzed by numerical method. The effects of motor and structure parameters on composite synchronous motion are discussed. Experiments on a vibrating test bench driven by three ERs are operated to validate the effectiveness of the proposed composite synchronization method, including a comparison with self-synchronization method.

A Kalman Filter Based Technique for Stator Turn-Fault Detection of the Induction Motors

NASA Astrophysics Data System (ADS)

Ghanbari, Teymoor; Samet, Haidar

2017-11-01

Monitoring of the Induction Motors (IMs) through stator current for different faults diagnosis has considerable economic and technical advantages in comparison with the other techniques in this content. Among different faults of an IM, stator and bearing faults are more probable types, which can be detected by analyzing signatures of the stator currents. One of the most reliable indicators for fault detection of IMs is lower sidebands of power frequency in the stator currents. This paper deals with a novel simple technique for detecting stator turn-fault of the IMs. Frequencies of the lower sidebands are determined using the motor specifications and their amplitudes are estimated by a Kalman Filter (KF). Instantaneous Total Harmonic Distortion (ITHD) of these harmonics is calculated. Since variation of the ITHD for the three-phase currents is considerable in case of stator turn-fault, the fault can be detected using this criterion, confidently. Different simulation results verify high performance of the proposed method. The performance of the method is also confirmed using some experiments.

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.

Self-modulation of primary motor cortex activity with motor and motor imagery tasks using real-time fMRI-based neurofeedback

PubMed Central

Berman, Brian D.; Horovitz, Silvina G.; Venkataraman, Gaurav; Hallett, Mark

2011-01-01

Advances in fMRI data acquisition and processing have made it possible to analyze brain activity as rapidly as the images are acquired allowing this information to be fed back to subjects in the scanner. The ability of subjects to learn to volitionally control localized brain activity within motor cortex using such real-time fMRI-based neurofeedback (NF) is actively being investigated as it may have clinical implications for motor rehabilitation after central nervous system injury and brain-computer interfaces. We investigated the ability of fifteen healthy volunteers to use NF to modulate brain activity within the primary motor cortex (M1) during a finger tapping and tapping imagery task. The M1 hand area ROI (ROIm) was functionally localized during finger tapping and a visual representation of BOLD signal changes within the ROIm fed back to the subject in the scanner. Surface EMG was used to assess motor output during tapping and ensure no motor activity was present during motor imagery task. Subjects quickly learned to modulate brain activity within their ROIm during the finger-tapping task, which could be dissociated from the magnitude of the tapping, but did not show a significant increase within the ROIm during the hand motor imagery task at the group level despite strongly activating a network consistent with the performance of motor imagery. The inability of subjects to modulate M1 proper with motor imagery may reflect an inherent difficulty in activating synapses in this area, with or without NF, since such activation may lead to M1 neuronal output and obligatory muscle activity. Future real-time fMRI-based NF investigations involving motor cortex may benefit from focusing attention on cortical regions other than M1 for feedback training or alternative feedback strategies such as measures of functional connectivity within the motor system. PMID:21803163

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. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Rail Brake System Using a Linear Induction Motor for Dynamic Braking

NASA Astrophysics Data System (ADS)

Sakamoto, Yasuaki; Kashiwagi, Takayuki; Tanaka, Minoru; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

One type of braking system for railway vehicles is the eddy current brake. Because this type of brake has the problem of rail heating, it has not been used for practical applications in Japan. Therefore, we proposed the use of a linear induction motor (LIM) for dynamic braking in eddy current brake systems. The LIM reduces rail heating and uses an inverter for self excitation. In this paper, we estimated the performance of an LIM from experimental results of a fundamental test machine and confirmed that the LIM generates an approximately constant braking force under constant current excitation. At relatively low frequencies, this braking force remains unaffected by frequency changes. The reduction ratio of rail heating is also approximately proportional to the frequency. We also confirmed that dynamic braking resulting in no electrical output can be used for drive control of the LIM. These characteristics are convenient for the realization of the LIM rail brake system.

Three-phase short circuit calculation method based on pre-computed surface for doubly fed induction generator

NASA Astrophysics Data System (ADS)

Ma, J.; Liu, Q.

2018-02-01

This paper presents an improved short circuit calculation method, based on pre-computed surface to determine the short circuit current of a distribution system with multiple doubly fed induction generators (DFIGs). The short circuit current, injected into power grid by DFIG, is determined by low voltage ride through (LVRT) control and protection under grid fault. However, the existing methods are difficult to calculate the short circuit current of DFIG in engineering practice due to its complexity. A short circuit calculation method, based on pre-computed surface, was proposed by developing the surface of short circuit current changing with the calculating impedance and the open circuit voltage. And the short circuit currents were derived by taking into account the rotor excitation and crowbar activation time. Finally, the pre-computed surfaces of short circuit current at different time were established, and the procedure of DFIG short circuit calculation considering its LVRT was designed. The correctness of proposed method was verified by simulation.

Robust fractional order sliding mode control of doubly-fed induction generator (DFIG)-based wind turbines.

PubMed

Ebrahimkhani, Sadegh

2016-07-01

Wind power plants have nonlinear dynamics and contain many uncertainties such as unknown nonlinear disturbances and parameter uncertainties. Thus, it is a difficult task to design a robust reliable controller for this system. This paper proposes a novel robust fractional-order sliding mode (FOSM) controller for maximum power point tracking (MPPT) control of doubly fed induction generator (DFIG)-based wind energy conversion system. In order to enhance the robustness of the control system, uncertainties and disturbances are estimated using a fractional order uncertainty estimator. In the proposed method a continuous control strategy is developed to achieve the chattering free fractional order sliding-mode control, and also no knowledge of the uncertainties and disturbances or their bound is assumed. The boundedness and convergence properties of the closed-loop signals are proven using Lyapunov׳s stability theory. Simulation results in the presence of various uncertainties were carried out to evaluate the effectiveness and robustness of the proposed control scheme. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

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.

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

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.

Use of an AC induction motor system for producing finger movements in human subjects.

PubMed

Proudlock, F A; Scott, J J

1998-12-01

This report describes the set-up and evaluation of a novel system for producing precise finger movements, for tests of movement perception. The specifications were to construct a system using commercially available components that were easy to use but which offered both flexibility and also high precision control. The system was constructed around an industrial AC induction motor with an optical encoder, controlled by an AC servo digital control module that could be programmed using a simple, high-level language. This set-up fulfilled the requirements regarding position and velocity control for a range of movements and also the facility for the subject to move the joint voluntarily while still attached to the motor. However a number of problems were encountered, the most serious being the level of vibration and the inability to vary the torque during movements. The vibration was reduced to the point where it did not affect the subject, by the introduction of mechanical dampening using an anti-vibration coupling and a pneumatic splint. The torque control could not be modified during rotation and so the system could only be operated using constant torque for any given movement.

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.

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…

Educational Inductive Gravimeter

ERIC Educational Resources Information Center

Nunn, John

2014-01-01

A simple inductive gravimeter constructed from a rigid plastic pipe and insulated copper wire is described. When a magnet is dropped through the vertically mounted pipe it induces small alternating voltages. These small signals are fed to the microphone input of a typical computer and sampled at a typical rate of 44.1 kHz using a custom computer…

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,…

Directed induction of functional motor neuron-like cells from genetically engineered human mesenchymal stem cells.

PubMed

Park, Hwan-Woo; Cho, Jung-Sun; Park, Chul-Kyu; Jung, Sung Jun; Park, Chang-Hwan; Lee, Shin-Jae; Oh, Seog Bae; Park, Young-Seok; Chang, Mi-Sook

2012-01-01

Cell replacement using stem cells is a promising therapeutic approach to treat degenerative motor neuron (MN) disorders, such as amyotrophic lateral sclerosis and spinal cord injury. Human bone marrow-derived mesenchymal stem cells (hMSCs) are a desirable cell source for autologous cell replacement therapy to treat nervous system injury due to their plasticity, low immunogenicity, and a lower risk of tumor formation than embryonic stem cells. However, hMSCs are inefficient with regards to differentiating into MN-like cells. To solve this limitation, we genetically engineered hMSCs to express MN-associated transcription factors, Olig2 and Hb9, and then treat the hMSCs expressing Olig2 and Hb9 with optimal MN induction medium (MNIM). This method of induction led to higher expression (>30% of total cells) of MN markers. Electrophysiological data revealed that the induced hMSCs had the excitable properties of neurons and were able to form functional connections with muscle fibers in vitro. Furthermore, when the induced hMSCs were transplanted into an injured organotypic rat spinal cord slice culture, an ex vivo model of spinal cord injury, they exhibited characteristics of MNs. The data strongly suggest that induced Olig2/Hb9-expressing hMSCs were clearly reprogrammed and directed toward a MN-like lineage. We propose that methods to induce Olig2 and Hb9, followed by further induction with MNIM have therapeutic potential for autologous cell replacement therapy to treat degenerative MN disorders.

Cortical Plasticity Induction by Pairing Subthalamic Nucleus Deep-Brain Stimulation and Primary Motor Cortical Transcranial Magnetic Stimulation in Parkinson's Disease.

PubMed

Udupa, Kaviraja; Bahl, Nina; Ni, Zhen; Gunraj, Carolyn; Mazzella, Filomena; Moro, Elena; Hodaie, Mojgan; Lozano, Andres M; Lang, Anthony E; Chen, Robert

2016-01-13

Noninvasive brain stimulation studies have shown abnormal motor cortical plasticity in Parkinson's disease (PD). These studies used peripheral nerve stimulation paired with transcranial magnetic stimulation (TMS) to primary motor cortex (M1) at specific intervals to induce plasticity. Induction of cortical plasticity through stimulation of the basal ganglia (BG)-M1 connections has not been studied. In the present study, we used a novel technique of plasticity induction by repeated pairing of deep-brain stimulation (DBS) of the BG with M1 stimulation using TMS. We hypothesize that repeated pairing of subthalamic nucleus (STN)-DBS and M1-TMS at specific time intervals will lead to plasticity in the M1. Ten PD human patients with STN-DBS were studied in the on-medication state with DBS set to 3 Hz. The interstimulus intervals (ISIs) between STN-DBS and TMS that produced cortical facilitation were determined individually for each patient. Three plasticity induction conditions with repeated pairings (180 times) at specific ISIs (∼ 3 and ∼ 23 ms) that produced cortical facilitation and a control ISI of 167 ms were tested in random order. Repeated pairing of STN-DBS and M1-TMS at short (∼ 3 ms) and medium (∼ 23 ms) latencies increased M1 excitability that lasted for at least 45 min, whereas the control condition (fixed ISI of 167 ms) had no effect. There were no specific changes in motor thresholds, intracortical circuits, or recruitment curves. Our results indicate that paired-associative cortical plasticity can be induced by repeated STN and M1 stimulation at specific intervals. These results show that STN-DBS can modulate cortical plasticity. We introduced a new experimental paradigm to test the hypothesis that pairing subthalamic nucleus deep-brain stimulation (STN-DBS) with motor cortical transcranial magnetic stimulation (M1-TMS) at specific times can induce cortical plasticity in patients with Parkinson's disease (PD). We found that repeated pairing of STN

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.

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.

Electric vehicle motors and controllers

NASA Astrophysics Data System (ADS)

Secunde, R. R.

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.

Induction generators for Wind Energy Conversion Systems. Part I: review of induction generator with squirrel cage rotor. Part II: the Double Output Induction Generator (DOIG). Progress report, July-December 1975

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jayadev, T.S.

1976-02-01

The application of induction generators in Wind Energy Conversion Systems (WECS) is described. The conventional induction generator, which is an induction machine with a squirrel cage rotor, had been used in large wind power plants in Europe, but has not caught much attention until now by designers of large systems in this country. The induction generator with a squirrel cage rotor is described and useful design techniques to build induction generators for wind energy application are outlined. The Double Output Induction Generator (DOIG) - so called because power is fed into the grid from the stator, as well as themore » rotor is described. It is a wound rotor induction machine with power electronics to convert rotor slip frequency power to that of line frequency.« less

Universal adaptive torque control for PM motors for field-weakening region operation

DOEpatents

Royak, Semyon [Beachwood, OH; Harbaugh, Mark M [Richfield, OH; Breitzmann, Robert J [South Russel, OH; Nondahl, Thomas A [Wauwatosa, WI; Schmidt, Peter B [Franklin, WI; Liu, Jingbo [Milwaukee, WI

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.

Extended cage adjustable speed electric motors and drive packages

DOEpatents

Hsu, John S.

1999-01-01

The rotor cage of a motor is extended, a second stator is coupled to this extended rotor cage, and the windings have the same number of poles. The motor torque and speed can be controlled by either injecting energy into or extracting energy out from the rotor cage. The motor produces less harmonics than existing doubly-fed motors. Consequently, a new type of low cost, high efficiency drive is produced.

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.

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.

Dual-loop self-optimizing robust control of wind power generation with Doubly-Fed Induction Generator.

PubMed

Chen, Quan; Li, Yaoyu; Seem, John E

2015-09-01

This paper presents a self-optimizing robust control scheme that can maximize the power generation for a variable speed wind turbine with Doubly-Fed Induction Generator (DFIG) operated in Region 2. A dual-loop control structure is proposed to synergize the conversion from aerodynamic power to rotor power and the conversion from rotor power to the electrical power. The outer loop is an Extremum Seeking Control (ESC) based generator torque regulation via the electric power feedback. The ESC can search for the optimal generator torque constant to maximize the rotor power without wind measurement or accurate knowledge of power map. The inner loop is a vector-control based scheme that can both regulate the generator torque requested by the ESC and also maximize the conversion from the rotor power to grid power. An ℋ(∞) controller is synthesized for maximizing, with performance specifications defined based upon the spectrum of the rotor power obtained by the ESC. Also, the controller is designed to be robust against the variations of some generator parameters. The proposed control strategy is validated via simulation study based on the synergy of several software packages including the TurbSim and FAST developed by NREL, Simulink and SimPowerSystems. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

An Intelligent Harmonic Synthesis Technique for Air-Gap Eccentricity Fault Diagnosis in Induction Motors

NASA Astrophysics Data System (ADS)

Li, De Z.; Wang, Wilson; Ismail, Fathy

2017-11-01

Induction motors (IMs) are commonly used in various industrial applications. To improve energy consumption efficiency, a reliable IM health condition monitoring system is very useful to detect IM fault at its earliest stage to prevent operation degradation, and malfunction of IMs. An intelligent harmonic synthesis technique is proposed in this work to conduct incipient air-gap eccentricity fault detection in IMs. The fault harmonic series are synthesized to enhance fault features. Fault related local spectra are processed to derive fault indicators for IM air-gap eccentricity diagnosis. The effectiveness of the proposed harmonic synthesis technique is examined experimentally by IMs with static air-gap eccentricity and dynamic air-gap eccentricity states under different load conditions. Test results show that the developed harmonic synthesis technique can extract fault features effectively for initial IM air-gap eccentricity fault detection.

Extended cage adjustable speed electric motors and drive packages

DOEpatents

Hsu, J.S.

1999-03-23

The rotor cage of a motor is extended, a second stator is coupled to this extended rotor cage, and the windings have the same number of poles. The motor torque and speed can be controlled by either injecting energy into or extracting energy out from the rotor cage. The motor produces less harmonics than existing doubly-fed motors. Consequently, a new type of low cost, high efficiency drive is produced. 12 figs.

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.

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.)

Somatic and movement inductions phantom limb in non-amputees

NASA Astrophysics Data System (ADS)

Casas, D. M.; Gentiletti, G. G.; Braidot, A. A.

2016-04-01

The illusion of the mirror box is a tool for phantom limb pain treatment; this article proposes the induction of phantom limb syndrome on non-amputees upper limb, with a neurological trick of the mirror box. With two study situations: a) Somatic Induction is a test of the literature reports qualitatively, and novel proposal b) Motor Induction, which is an objective report by recording surface EEG. There are 3 cases proposed for Motor illusion, for which grasped movement is used: 1) Control: movement is made, 2) illusion: the mirror box is used, and 3) Imagination: no movement is executed; the subject only imagines its execution. Three different tasks are registered for each one of them (left hand, right hand, and both of them). In 64% of the subjects for somatic experience, a clear response to the illusion was observed. In the experience of motor illusion, cortical activation is detected in both hemispheres of the primary motor cortex during the illusion, where the hidden hand remains motionless. These preliminary findings in phantom limb on non-amputees can be a tool for neuro-rehabilitation and neuro-prosthesis control training.

Structural optimisation of cage induction motors using finite element analysis

NASA Astrophysics Data System (ADS)

Palko, S.

The current trend in motor design is to have highly efficient, low noise, low cost, and modular motors with a high power factor. High torque motors are useful in applications like servo motors, lifts, cranes, and rolling mills. This report contains a detailed review of different optimization methods applicable in various design problems. Special attention is given to the performance of different methods, when they are used with finite element analysis (FEA) as an objective function, and accuracy problems arising from the numerical simulations. Also an effective method for designing high starting torque and high efficiency motors is presented. The method described in this work utilizes FEA combined with algorithms for the optimization of the slot geometry. The optimization algorithm modifies the position of the nodal points in the element mesh. The number of independent variables ranges from 14 to 140 in this work.

Variable-frequency synchronous motor drives for electric vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 ofmore » 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.).« less

Variable-frequency synchronous motor drives for electric vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 designmore » 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.).« less

Induction of motor associative plasticity in the posterior parietal cortex-primary motor network.

PubMed

Chao, Chi-Chao; Karabanov, Anke Ninija; Paine, Rainer; Carolina de Campos, Ana; Kukke, Sahana N; Wu, Tianxia; Wang, Han; Hallett, Mark

2015-02-01

There is anatomical and functional connectivity between the primary motor cortex (M1) and posterior parietal cortex (PPC) that plays a role in sensorimotor integration. In this study, we applied corticocortical paired-associative stimuli to ipsilateral PPC and M1 (parietal ccPAS) in healthy right-handed subjects to test if this procedure could modulate M1 excitability and PPC-M1 connectivity. One hundred and eighty paired transcranial magnetic stimuli to the PPC and M1 at an interstimulus interval (ISI) of 8 ms were delivered at 0.2 Hz. We found that parietal ccPAS in the left hemisphere increased the excitability of conditioned left M1 assessed by motor evoked potentials (MEPs) and the input-output curve. Motor behavior assessed by the Purdue pegboard task was unchanged compared with controls. At baseline, conditioning stimuli over the left PPC potentiated MEPs from left M1 when ISI was 8 ms. This interaction significantly attenuated at 60 min after left parietal ccPAS. Additional experiments showed that parietal ccPAS induced plasticity was timing-dependent, was absent if ISI was 100 ms, and could also be seen in the right hemisphere. Our results suggest that parietal ccPAS can modulate M1 excitability and PPC-M1 connectivity and is a new approach to modify motor excitability and sensorimotor interaction. Published by Oxford University Press 2013. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Comparison of linear synchronous and induction motors

DOT National Transportation Integrated Search

2004-06-01

A propulsion prade study was conducted as part of the Colorado Maglev Project of FTA's Urban Maglev Technology Development Program to identify and evaluate prospective linear motor designs that could potentially meet the system performance requiremen...

Electric motor-transformer aggregate in hermetic objects of transport vehicles

NASA Astrophysics Data System (ADS)

Zabora, Igor

2017-10-01

The construction and features of operation for new electrical unit - electric motor-transformer aggregate (DTA) are considered. Induction motors are intended for operation in hermetic plants with extreme conditions surrounding gas, steam-to-gas and liquid environment at a high temperature (to several hundred of degrees). Main objective of spent researches is the substantiation of possibility reliable and effective electric power transform with electric machine means directly in hermetic objects with extreme conditions environment by means of new DTA. The principle and job analysis of new disk induction motors of block-module type are observed.

Induction of ketosis in rats fed low-carbohydrate, high-fat diets depends on the relative abundance of dietary fat and protein.

PubMed

Bielohuby, Maximilian; Menhofer, Dominik; Kirchner, Henriette; Stoehr, Barbara J M; Müller, Timo D; Stock, Peggy; Hempel, Madlen; Stemmer, Kerstin; Pfluger, Paul T; Kienzle, Ellen; Christ, Bruno; Tschöp, Matthias H; Bidlingmaier, Martin

2011-01-01

Low-carbohydrate/high-fat diets (LC-HFDs) in rodent models have been implicated with both weight loss and as a therapeutic approach to treat neurological diseases. LC-HFDs are known to induce ketosis; however, systematic studies analyzing the impact of the macronutrient composition on ketosis induction and weight loss success are lacking. Male Wistar rats were pair-fed for 4 wk either a standard chow diet or one of three different LC-HFDs, which only differed in the relative abundance of fat and protein (percentages of fat/protein in dry matter: LC-75/10; LC-65/20; LC-55/30). We subsequently measured body composition by nuclear magnetic resonance (NMR), analyzed blood chemistry and urine acetone content, evaluated gene expression changes of key ketogenic and gluconeogenic genes, and measured energy expenditure (EE) and locomotor activity (LA) during the first 4 days and after 3 wk on the respective diets. Compared with chow, rats fed with LC-75/10, LC-65/20, and LC-55/30 gained significantly less body weight. Reductions in body weight were mainly due to lower lean body mass and paralleled by significantly increased fat mass. Levels of β-hydroxybutyate were significantly elevated feeding LC-75/10 and LC-65/20 but decreased in parallel to reductions in dietary fat. Acetone was about 16-fold higher with LC-75/10 only (P < 0.001). In contrast, rats fed with LC-55/30 were not ketotic. Serum fibroblast growth factor-21, hepatic mRNA expression of hydroxymethylglutaryl-CoA-lyase, peroxisome proliferator-activated receptor-γ coactivator-1α, and peroxisome proliferator-activated receptor-γ coactivator-1β were increased with LC-75/10 only. Expression of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase was downregulated by 50-70% in LC-HF groups. Furthermore, EE and LA were significantly decreased in all groups fed with LC-HFDs after 3 wk on the diets. In rats, the absence of dietary carbohydrates per se does not induce ketosis. LC-HFDs must be high in fat

The operation of a single-sided linear induction motor with squirrel-cage and solid-steel reaction rails

NASA Astrophysics Data System (ADS)

Eastham, A. R.; Katz, R. M.

1980-09-01

Two test programs have been conducted to evaluate the performance of a single-sided linear induction motor with a squirrel-cage reaction rail and with a solid steel reaction rail. A 1.73-m-long six-pole stator interacted with the rails mounted on the rim of a 7.6-m-diam wheel. A 64-channel data acquisition system allowed tests to be performed over a wide range of operating conditions at speeds up to 20 m/sec. Typical test results which compare and contrast the mechanical, electrical and magnetic behavior of the SLIMs are presented. The test data are being used to assess the SLIM as an integrated suspension/propulsion system and for other transportation applications.

Comparative induction of nitrate reductase by nitrate and nitrite in barley leaves

NASA Technical Reports Server (NTRS)

Aslam, M.; Rosichan, J. L.; Huffaker, R. C.

1987-01-01

The comparative induction of nitrate reductase (NR) by ambient NO3- and NO2- as a function of influx, reduction (as NR was induced) and accumulation in detached leaves of 8-day-old barley (Hordeum vulgare L.) seedlings was determined. The dynamic interaction of NO3- influx, reduction and accumulation on NR induction was shown. The activity of NR, as it was induced, influenced its further induction by affecting the internal concentration of NO3-. As the ambient concentration of NO3- increased, the relative influences imposed by influx and reduction on NO3- accumulation changed with influx becoming a more predominant regulant. Significant levels of NO3- accumulated in NO2(-)-fed leaves. When the leaves were supplied cycloheximide or tungstate along with NO2-, about 60% more NO3- accumulated in the leaves than in the absence of the inhibitors. In NO3(-)-supplied leaves NR induction was observed at an ambient concentration of as low as 0.02 mM. No NR induction occurred in leaves supplied with NO2- until the ambient NO2- concentration was 0.5 mM. In fact, NR induction from NO2- solutions was not seen until NO3- was detected in the leaves. The amount of NO3- accumulating in NO2(-)-fed leaves induced similar levels of NR as did equivalent amounts of NO3- accumulating from NO3(-)-fed leaves. In all cases the internal concentration of NO3-, but not NO2-, was highly correlated with the amount of NR induced. The evidence indicated that NO3- was a more likely inducer of NR than was NO2-.

The analysis of 3-phase squirrel-cage induction motors including space harmonics and mutual slotting in transient and steady state

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paap, G.C.

1991-03-01

From general equations which describe the transient electromechanical behavior of the asynchronous squirrel-cage motor, and which include the influence of space harmonics and mutual slotting, simplified models are derived and compared. The models derived are demonstrated in examples where special attention is paid to the influence of the place of the harmonics in the mutual inductance matrix and the influence of mutual slotting. Further, the steady-state equations are derived and the back-transformation for the stator and rotor currents is given. One example is compared with the result of measurements.

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.

Molybdenum deprivation, purine ingestion and an astrocyte-associated motor neurone syndrome in sheep: assumed clinical effects of inosine.

PubMed

Bourke, Ca

2015-03-01

An astrocyte-associated motor neurone syndrome was produced in molybdenum-deprived sheep fed xanthosine. Mo-deprived sheep fed inosine, adenosine or guanosine would be also expected to develop astrocyte-associated motor neurone syndromes, because all these purine nucleosides can act as neuromodulators and all depend on the Mo-associated enzyme xanthine oxidase-dehydrogenase for their catabolism. To investigate the relationship between inosine ingestion and low Mo concentration, eight sheep were fed lucerne chaff with a Mo value <0.10 ppm and the Mo antagonist, sodium tungstate, for 21 weeks, with inosine (35 mg/kg/day) fed for the last 18 of these weeks. This clinical study was uncontrolled. An astrocyte-associated motor neurone syndrome was produced in three sheep 18-27 months later. It was characterised by diaphragmatic, laryngeal, lingual and pharyngeal muscle weakness. The diaphragmatic muscle weakness was the most severe and potentially lethal. These findings suggest that purinergic neuromodulation of respiration, vocalisation and swallowing is different to that of limb movement. The syndrome produced, and assumed to be caused by the treatment given, has not been reported in livestock. A similar syndrome is seen in human motor neurone disease, but not in equine motor neurone disease, and this is consistent with it being an upper, not a lower, motor neurone effect. © 2015 Australian Veterinary Association.

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...

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hwang, Don-Ha; Woo, Byung-Chul; Sun, Jong-Ho

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. Amore » 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.« less

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.

Effect of inter-train interval on the induction of repetition suppression of motor-evoked potentials using transcranial magnetic stimulation.

PubMed

Pitkänen, Minna; Kallioniemi, Elisa; Julkunen, Petro

2017-01-01

Repetition suppression (RS) is evident as a weakened response to repeated stimuli after the initial response. RS has been demonstrated in motor-evoked potentials (MEPs) induced with transcranial magnetic stimulation (TMS). Here, we investigated the effect of inter-train interval (ITI) on the induction of RS of MEPs with the attempt to optimize the investigative protocols. Trains of TMS pulses, targeted to the primary motor cortex by neuronavigation, were applied at a stimulation intensity of 120% of the resting motor threshold. The stimulus trains included either four or twenty pulses with an inter-stimulus interval (ISI) of 1 s. The ITI was here defined as the interval between the last pulse in a train and the first pulse in the next train; the ITIs used here were 1, 3, 4, 6, 7, 12, and 17 s. RS was observed with all ITIs except with the ITI of 1 s, in which the ITI was equal to ISI. RS was more pronounced with longer ITIs. Shorter ITIs may not allow sufficient time for a return to baseline. RS may reflect a startle-like response to the first pulse of a train followed by habituation. Longer ITIs may allow more recovery time and in turn demonstrate greater RS. Our results indicate that RS can be studied with confidence at relatively short ITIs of 6 s and above.

Influence of cutting strains and magnetic anisotropy of electrical steel on the air gap flux distribution of an induction motor

NASA Astrophysics Data System (ADS)

Hribernik, Božo

1984-02-01

This paper describes an iterative algorithm for the simulation of various real magnetic materials in a small induction motor and their influence on the flux distribution in the air gap. Two standard materials, fully-, and semi-processed steel strips were used. The nonlinearity of the magnetization curve, the influence of cutting strains and magnetic anisotropy are also considered. All these influences bring out the facts that the uniformly rotated and sine form exitation causes a nonuniformly rotated and deformed magnetic field in the air gap of the machine and that the magnetization current is winding place dependent.

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.

Parallel steady state studies on a milliliter scale accelerate fed-batch bioprocess design for recombinant protein production with Escherichia coli.

PubMed

Schmideder, Andreas; Cremer, Johannes H; Weuster-Botz, Dirk

2016-11-01

In general, fed-batch processes are applied for recombinant protein production with Escherichia coli (E. coli). However, state of the art methods for identifying suitable reaction conditions suffer from severe drawbacks, i.e. direct transfer of process information from parallel batch studies is often defective and sequential fed-batch studies are time-consuming and cost-intensive. In this study, continuously operated stirred-tank reactors on a milliliter scale were applied to identify suitable reaction conditions for fed-batch processes. Isopropyl β-d-1-thiogalactopyranoside (IPTG) induction strategies were varied in parallel-operated stirred-tank bioreactors to study the effects on the continuous production of the recombinant protein photoactivatable mCherry (PAmCherry) with E. coli. Best-performing induction strategies were transferred from the continuous processes on a milliliter scale to liter scale fed-batch processes. Inducing recombinant protein expression by dynamically increasing the IPTG concentration to 100 µM led to an increase in the product concentration of 21% (8.4 g L -1 ) compared to an implemented high-performance production process with the most frequently applied induction strategy by a single addition of 1000 µM IPGT. Thus, identifying feasible reaction conditions for fed-batch processes in parallel continuous studies on a milliliter scale was shown to be a powerful, novel method to accelerate bioprocess design in a cost-reducing manner. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1426-1435, 2016. © 2016 American Institute of Chemical Engineers.

Heritability of motor control and motor learning

PubMed Central

Missitzi, Julia; Gentner, Reinhard; Misitzi, Angelica; Geladas, Nickos; Politis, Panagiotis; Klissouras, Vassilis; Classen, Joseph

2013-01-01

Abstract The aim of this study was to elucidate the relative contribution of genes and environment on individual differences in motor control and acquisition of a force control task, in view of recent association studies showing that several candidate polymorphisms may have an effect on them. Forty‐four healthy female twins performed brisk isometric abductions with their right thumb. Force was recorded by a transducer and fed back to the subject on a computer screen. The task was to place the tracing of the peak force in a force window defined between 30% and 40% of the subject's maximum force, as determined beforehand. The initial level of proficiency was defined as the number of attempts reaching the force window criterion within the first 100 trials. The difference between the number of successful trials within the last and the first 100 trials was taken as a measure of motor learning. For motor control, defined by the initial level of proficiency, the intrapair differences in monozygotic (MZ) and dizygotic (DZ) twins were 6.8 ± 7.8 and 13.8 ± 8.4, and the intrapair correlations 0.77 and 0.39, respectively. Heritability was estimated at 0.68. Likewise for motor learning intrapair differences in the increment of the number of successful trials in MZ and DZ twins were 5.4 ± 5.2 and 12.8 ± 7, and the intrapair correlations 0.58 and 0.19. Heritability reached 0.70. The present findings suggest that heredity accounts for a major part of existing differences in motor control and motor learning, but uncertainty remains which gene polymorphisms may be responsible. PMID:24744865

Detection of broken rotor bar faults in induction motor at low load using neural network.

PubMed

Bessam, B; Menacer, A; Boumehraz, M; Cherif, H

2016-09-01

The knowledge of the broken rotor bars characteristic frequencies and amplitudes has a great importance for all related diagnostic methods. The monitoring of motor faults requires a high resolution spectrum to separate different frequency components. The Discrete Fourier Transform (DFT) has been widely used to achieve these requirements. However, at low slip this technique cannot give good results. As a solution for these problems, this paper proposes an efficient technique based on a neural network approach and Hilbert transform (HT) for broken rotor bar diagnosis in induction machines at low load. The Hilbert transform is used to extract the stator current envelope (SCE). Two features are selected from the (SCE) spectrum (the amplitude and frequency of the harmonic). These features will be used as input for neural network. The results obtained are astonishing and it is capable to detect the correct number of broken rotor bars under different load conditions. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Static air-gap eccentricity fault diagnosis using rotor slot harmonics in line neutral voltage of three-phase squirrel cage induction motor

NASA Astrophysics Data System (ADS)

Oumaamar, Mohamed El Kamel; Maouche, Yassine; Boucherma, Mohamed; Khezzar, Abdelmalek

2017-02-01

The mixed eccentricity fault detection in a squirrel cage induction motor has been thoroughly investigated. However, a few papers have been related to pure static eccentricity fault and the authors focused on the RSH harmonics presented in stator current. The main objective of this paper is to present an alternative method based on the analysis of line neutral voltage taking place between the supply and the stator neutrals in order to detect air-gap static eccentricity, and to highlight the classification of all RSH harmonics in line neutral voltage. The model of squirrel cage induction machine relies on the rotor geometry and winding layout. Such developed model is used to analyze the impact of the pure static air-gap eccentricity by predicting the related frequencies in the line neutral voltage spectrum. The results show that the line neutral voltage spectrum are more sensitive to the air-gap static eccentricity fault compared to stator current one. The theoretical analysis and simulated results are confirmed by experiments.

Real-time simulation of a Doubly-Fed Induction Generator based wind power system on eMEGASimRTM Real-Time Digital Simulator

NASA Astrophysics Data System (ADS)

Boakye-Boateng, Nasir Abdulai

The growing demand for wind power integration into the generation mix prompts the need to subject these systems to stringent performance requirements. This study sought to identify the required tools and procedures needed to perform real-time simulation studies of Doubly-Fed Induction Generator (DFIG) based wind generation systems as basis for performing more practical tests of reliability and performance for both grid-connected and islanded wind generation systems. The author focused on developing a platform for wind generation studies and in addition, the author tested the performance of two DFIG models on the platform real-time simulation model; an average SimpowerSystemsRTM DFIG wind turbine, and a detailed DFIG based wind turbine using ARTEMiSRTM components. The platform model implemented here consists of a high voltage transmission system with four integrated wind farm models consisting in total of 65 DFIG based wind turbines and it was developed and tested on OPAL-RT's eMEGASimRTM Real-Time Digital Simulator.

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.

Theobromine up-regulates cerebral brain-derived neurotrophic factor and facilitates motor learning in mice.

PubMed

Yoneda, Mitsugu; Sugimoto, Naotoshi; Katakura, Masanori; Matsuzaki, Kentaro; Tanigami, Hayate; Yachie, Akihiro; Ohno-Shosaku, Takako; Shido, Osamu

2017-01-01

Theobromine, which is a caffeine derivative, is the primary methylxanthine produced by Theobroma cacao. Theobromine works as a phosphodiesterase (PDE) inhibitor to increase intracellular cyclic adenosine monophosphate (cAMP). cAMP activates the cAMP-response element-binding protein (CREB), which is involved in a large variety of brain processes, including the induction of the brain-derived neurotrophic factor (BDNF). BDNF supports cell survival and neuronal functions, including learning and memory. Thus, cAMP/CREB/BDNF pathways play an important role in learning and memory. Here, we investigated whether orally administered theobromine could act as a PDE inhibitor centrally and affect cAMP/CREB/BDNF pathways and learning behavior in mice. The mice were divided into two groups. The control group (CN) was fed a normal diet, whereas the theobromine group (TB) was fed a diet supplemented with 0.05% theobromine for 30 days. We measured the levels of theobromine, phosphorylated vasodilator-stimulated phosphoprotein (p-VASP), phosphorylated CREB (p-CREB), and BDNF in the brain. p-VASP was used as an index of cAMP increases. Moreover, we analyzed the performance of the mice on a three-lever motor learning task. Theobromine was detectable in the brains of TB mice. The brain levels of p-VASP, p-CREB, and BDNF were higher in the TB mice compared with those in the CN mice. In addition, the TB mice performed better on the three-lever task than the CN mice did. These results strongly suggested that orally administered theobromine acted as a PDE inhibitor in the brain, and it augmented the cAMP/CREB/BDNF pathways and motor learning in mice. Copyright © 2016 Elsevier Inc. All rights reserved.

Electronically commutated motors for vehicle applications

NASA Astrophysics Data System (ADS)

Echolds, E. F.

1980-02-01

Two permanent magnet electronically commutated motors for electric vehicle traction are discussed. One, based on existing technology, produces 23 kW (peak) at 26,000 rpm, and 11 kW continuous at 18,000 rpm. The motor has a conventional design: a four-pole permanent magnet rotor and a three-phase stator similar to those used on ordinary induction motors. The other, advanced technology motor, is rated at 27 kW (peak) at 14,000 rpm, and 11 kW continuous at 10,500 rpm. The machine employs a permanent magnet rotor and a novel ironless stator design in an axial air gap, homopolar configuration. Comparison of the new motors with conventional brush type machines indicates potential for substantial cost savings.

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.

Ultra-Efficient and Power Dense Electric Motors for U. S. Industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melfi, Michael J.; Schiferl, Richard F.; Umans, Stephen D.

2013-03-12

The primary purpose of this project was to combine the ease-of-installation and ease-of-use attributes of industrial induction motors with the low-loss and small size and weight advantages of PM motors to create an ultra-efficient, high power density industrial motor that can be started across-the-line or operated from a standard, Volts/Hertz drive without the need for a rotor position feedback device. PM motor products that are currently available are largely variable speed motors that require a special adjustable speed drive with rotor position feedback. The reduced size and weight helps to offset the magnet cost in order make these motors commerciallymore » viable. The scope of this project covers horsepower ratings from 20 ? 500. Prototypes were built and tested at ratings ranging from 30 to 250 HP. Since fans, pumps and compressors make up a large portion of industrial motor applications, the motor characteristics are tailored to those applications. Also, since there is extensive use of adjustable frequency inverters in these applications, there is the opportunity to design for an optimal pole number and operate at other than 60 Hz frequency when inverters are utilized. Designs with four and eight pole configurations were prototyped as part of this work. Four pole motors are the most commonly used configuration in induction motors today. The results of the prototype design, fabrication, and testing were quite successful. The 50 HP rating met all of the design goals including efficiency and power density. Tested values of motor losses at 50 HP were 30% lower than energy efficient induction motors and the motor weight is 35% lower than the energy efficient induction motor of the same rating. Further, when tested at the 30 HP rating that is normally built in this 286T frame size, the efficiency far exceeds the project design goals with 30 HP efficiency levels indicating a 55% reduction in loss compared to energy efficient motors with a motor weight that is a

Induction of apoptosis by thrombin in the cultured neurons of dorsal motor nucleus of the vagus.

PubMed

Wu, X; Zhang, W; Li, J-Y; Chai, B-X; Peng, J; Wang, H; Mulholland, M W

2011-03-01

A previous study demonstrated the presence of protease-activated receptor (PAR) 1 and 2 in the dorsal motor nucleus of vagus (DMV). The aim of this study is to characterize the effect of thrombin on the apoptosis of DMV neurons. The dorsal motor nucleus of vagus neurons were isolated from neonatal rat brainstems using micro-dissection and enzymatic digestion and cultured. Apoptosis of DMV neurons were examined in cultured neurons. Apoptotic neuron was examined by TUNEL and ELISA. Data were analyzed using anova and Student's t-test. Exposure of cultured DMV neurons to thrombin (0.1 to 10 U mL(-1)) for 24 h significantly increased apoptosis. Pretreatment of DMV neurons with hirudin attenuated the apoptotic effect of thrombin. Similar induction of apoptosis was observed for the PAR1 receptor agonist SFLLR, but not for the PAR3 agonist TFRGAP, nor for the PAR4 agonist YAPGKF. Protease-activated receptors 1 receptor antagonist Mpr(Cha) abolished the apoptotic effect of thrombin, while YPGKF, a specific antagonist for PAR4, demonstrated no effect. After administration of thrombin, phosphorylation of JNK and P38 occurred as early as 15 min, and remained elevated for up to 45 min. Pretreatment of DMV neurons with SP600125, a specific inhibitor for JNK, or SB203580, a specific inhibitor for P38, significantly inhibited apoptosis induced by thrombin. Thrombin induces apoptosis in DMV neurons through a mechanism involving the JNK and P38 signaling pathways. © 2010 Blackwell Publishing Ltd.

Role of nitrate and nitrite in the induction of nitrite reductase in leaves of barley seedlings

NASA Technical Reports Server (NTRS)

Aslam, M.; Huffaker, R. C.

1989-01-01

The role of NO3- and NO2- in the induction of nitrite reductase (NiR) activity in detached leaves of 8-day-old barley (Hordeum vulgare L.) seedlings was investigated. Barley leaves contained 6 to 8 micromoles NO2-/gram fresh weight x hour of endogenous NiR activity when grown in N-free solutions. Supply of both NO2- and NO3- induced the enzyme activity above the endogenous levels (5 and 10 times, respectively at 10 millimolar NO2- and NO3- over a 24 hour period). In NO3(-)-supplied leaves, NiR induction occurred at an ambient NO3- concentration of as low as 0.05 millimolar; however, no NiR induction was found in leaves supplied with NO2- until the ambient NO2- concentration was 0.5 millimolar. Nitrate accumulated in NO2(-)-fed leaves. The amount of NO3- accumulating in NO2(-)-fed leaves induced similar levels of NiR as did equivalent amounts of NO3- accumulating in NO3(-)-fed leaves. Induction of NiR in NO2(-)-fed leaves was not seen until NO3- was detectable (30 nanomoles/gram fresh weight) in the leaves. The internal concentrations of NO3-, irrespective of N source, were highly correlated with the levels of NiR induced. When the reduction of NO3- to NO2- was inhibited by WO4(2-), the induction of NiR was inhibited only partially. The results indicate that in barley leaves in NiR is induced by NO3- directly, i.e. without being reduced to NO2-, and that absorbed NO2- induces the enzyme activity indirectly after being oxidized to NO3- within the leaf.

Limitations of the Conventional Phase Advance Method for Constant Power Operation of the Brushless DC Motor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawler, J.S.

2001-10-29

The brushless dc motor (BDCM) has high-power density and efficiency relative to other motor types. These properties make the BDCM well suited for applications in electric vehicles provided a method can be developed for driving the motor over the 4 to 6:1 constant power speed range (CPSR) required by such applications. The present state of the art for constant power operation of the BDCM is conventional phase advance (CPA) [1]. In this paper, we identify key limitations of CPA. It is shown that the CPA has effective control over the developed power but that the current magnitude is relatively insensitivemore » to power output and is inversely proportional to motor inductance. If the motor inductance is low, then the rms current at rated power and high speed may be several times larger than the current rating. The inductance required to maintain rms current within rating is derived analytically and is found to be large relative to that of BDCM designs using high-strength rare earth magnets. Th us, the CPA requires a BDCM with a large equivalent inductance.« less

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

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.

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

PubMed

Zaafouri, Abderrahmen; Regaya, Chiheb Ben; Azza, Hechmi Ben; 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. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

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. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

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.

Methionine deficiency in rats fed soy protein induces hypercholesterolemia and potentiates lipoprotein susceptibility to peroxidation.

PubMed

Moundras, C; Rémésy, C; Levrat, M A; Demigné, C

1995-09-01

A number of studies have provided evidence that plant proteins, especially soy protein, have a cholesterol-lowering effect as compared with casein. However, dietary supply of sulfur amino acids may be deficient when soy protein is present in the diet at a suboptimal level, which could affect lipid metabolism. Accordingly, in rats fed 13% protein diets, soy protein feeding resulted in a cholesterol-increasing effect (+18%), which could be counteracted by methionine supplementation (0.4%). In contrast, soy protein was effective in decreasing plasma triglyceride, as compared with levels in rats fed casein; this triglyceride-lowering effect was entirely abolished by methionine supplementation. The hypercholesterolemic effect of soy protein was characterized by a higher cholesterol content in low-density lipoprotein (LDL) and high-density lipoprotein 1 (HDL1) fractions, together with a marked induction of hepatic hydroxymethyl glutaryl coenzyme A (HMG CoA) reductase activity and to a lesser extent cholesterol 7 alpha-hydroxylase. There was practically no induction of these enzymes, as compared with levels in rats fed casein diets, when the soy protein diet was supplemented with methionine. Very-low-density lipoprotein (VLDL) plus LDL susceptibility to peroxidation was higher in rats fed soy protein than in casein-fed rats, which could reflect in part the lack of sulfur amino acid availability, since methionine supplementation led to a partial recovery of lipoprotein resistance to peroxidation. These findings suggest that amino acid imbalance could be atherogenic by increasing circulating cholesterol and leading to a higher lipoprotein susceptibility to peroxidation.

Passive magnetic bearing for a motor-generator

DOEpatents

Post, Richard F [Walnut Creek, CA

2006-07-18

Conductive lap windings are interleaved with conventional loops in the stator of a motor-generator. The rotor provides magnetic induction lines that, when rotated, cut across the lap windings and the loops. When the rotor is laterally displaced from its equilibrium axis of rotation, its magnetic lines of induction induce a current in the interleaved lap windings. The induced current interacts with the magnetic lines of induction of the rotor in accordance with Lenz's law to generate a radial force that returns the rotor to its equilibrium axis of rotation.

Mood induction effects on motor sequence learning and stop signal reaction time.

PubMed

Greeley, Brian; Seidler, Rachael D

2017-01-01

The neurobiological theory of positive affect proposes that positive mood states may benefit cognitive performance due to an increase of dopamine throughout the brain. However, the results of many positive affect studies are inconsistent; this may be due to individual differences. The relationship between dopamine and performance is not linear, but instead follows an inverted "U" shape. Given this, we hypothesized that individuals with high working memory capacity, a proxy measure for dopaminergic transmission, would not benefit from positive mood induction and in fact performance in dopamine-mediated tasks would decline. In contrast, we predicted that individuals with low working memory capacities would receive the most benefit after positive mood induction. Here, we explored the effect of positive affect on two dopamine-mediated tasks, an explicit serial reaction time sequence learning task and the stop signal task, predicting that an individual's performance is modulated not only by working memory capacity, but also on the type of mood. Improvements in explicit sequence learning from pre- to post-positive mood induction were associated with working memory capacity; performance declined in individuals with higher working memory capacities following positive mood induction, but improved in individuals with lower working memory capacities. This was not the case for negative or neutral mood induction. Moreover, there was no relationship between the change in stop signal reaction time with any of the mood inductions and individual differences in working memory capacity. These results provide partial support for the neurobiological theory of positive affect and highlight the importance of taking into account individual differences in working memory when examining the effects of positive mood induction.

Induction motor broken rotor bar fault location detection through envelope analysis of start-up current using Hilbert transform

NASA Astrophysics Data System (ADS)

Abd-el-Malek, Mina; Abdelsalam, Ahmed K.; Hassan, Ola E.

2017-09-01

Robustness, low running cost and reduced maintenance lead Induction Motors (IMs) to pioneerly penetrate the industrial drive system fields. Broken rotor bars (BRBs) can be considered as an important fault that needs to be early assessed to minimize the maintenance cost and labor time. The majority of recent BRBs' fault diagnostic techniques focus on differentiating between healthy and faulty rotor cage. In this paper, a new technique is proposed for detecting the location of the broken bar in the rotor. The proposed technique relies on monitoring certain statistical parameters estimated from the analysis of the start-up stator current envelope. The envelope of the signal is obtained using Hilbert Transformation (HT). The proposed technique offers non-invasive, fast computational and accurate location diagnostic process. Various simulation scenarios are presented that validate the effectiveness of the proposed technique.

Nonlinear SVM-DTC for induction motor drive using input-output feedback linearization and high order sliding mode control.

PubMed

Ammar, Abdelkarim; Bourek, Amor; Benakcha, Abdelhamid

2017-03-01

This paper presents a nonlinear Direct Torque Control (DTC) strategy with Space Vector Modulation (SVM) for an induction motor. A nonlinear input-output feedback linearization (IOFL) is implemented to achieve a decoupled torque and flux control and the SVM is employed to reduce high torque and flux ripples. Furthermore, the control scheme performance is improved by inserting a super twisting speed controller in the outer loop and a load torque observer to enhance the speed regulation. The combining of dual nonlinear strategies ensures a good dynamic and robustness against parameters variation and disturbance. The system stability has been analyzed using Lyapunov stability theory. The effectiveness of the control algorithm is investigated by simulation and experimental validation using Matlab/Simulink software with real-time interface based on dSpace 1104. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

Code of Federal Regulations, 2014 CFR

2014-01-01

... full load efficiency Capacitor-start capacitor-run and capacitor-start induction-run Open motors... 10 Energy 3 2014-01-01 2014-01-01 false Small electric motors energy conservation standards and... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy Conservation...

10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

Code of Federal Regulations, 2012 CFR

2012-01-01

... full load efficiency Capacitor-start capacitor-run and capacitor-start induction-run Open motors... 10 Energy 3 2012-01-01 2012-01-01 false Small electric motors energy conservation standards and... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy Conservation...

10 CFR 431.446 - Small electric motors energy conservation standards and their effective dates.

Code of Federal Regulations, 2013 CFR

2013-01-01

... full load efficiency Capacitor-start capacitor-run and capacitor-start induction-run Open motors... 10 Energy 3 2013-01-01 2013-01-01 false Small electric motors energy conservation standards and... EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Small Electric Motors Energy Conservation...

High temperature superconducting synchronous motor design and test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schiferl, R.; Zhang, B.; Shoykhet, B.

1996-10-01

High horsepower synchronous motors with high temperature superconducting (HTS) field windings offer the potential to cut motor operating losses in half compared to conventional energy efficient induction motors available today. The design, construction and test of a prototype, air core, synchronous motor with helium gas cooled HTS field coils will be described in this paper. The work described is part of a US Department of Energy, Superconductivity Partnership Initiative award. The motor uses a modified conventional motor armature combined with a vacuum insulated rotor that contains the four racetrack-shaped HTS field coils. The rotor is cooled by helium gas somore » that the HTS coils operate at a temperature of 30 K. This paper provides a status report on HTS motor research and development at Reliance Lab., Rockwell Automation that will lead to commercial HTS motors for utility and industrial applications.« less

Development of Ulta-Efficient Electric Motors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shoykhet, B.; Schiferl, R.; Duckworth, R.

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 industrialmore » 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

General Theory of the Double Fed Synchronous Machine. Ph.D. Thesis - Swiss Technological Univ., 1950

NASA Technical Reports Server (NTRS)

El-Magrabi, M. G.

1982-01-01

Motor and generator operation of a double-fed synchronous machine were studied and physically and mathematically treated. Experiments with different connections, voltages, etc. were carried out. It was concluded that a certain degree of asymmetry is necessary for the best utilization of the machine.

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.

2017-02-01

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.

Mechanism For Adjustment Of Commutation Of Brushless Motor

NASA Technical Reports Server (NTRS)

Schaefer, Richard E.

1995-01-01

Mechanism enables adjustment of angular position of set of Hall-effect devices that sense instantaneous shaft angle of brushless dc motor. Outputs of sensors fed to commutation circuitry. Measurement of shaft angle essential for commutation; that is, application of voltage to stator windings must be synchronized with shaft angle. To obtain correct angle measurement for commutation, Hall-effect angle sensors positioned at proper reference angle. The present mechanism accelerates adjustment procedure and makes it possible to obtain more accurate indication of minimum-current position because it provides for adjustment while motor running.

Finite Element Analysis in the Estimation of Air-Gap Torque and Surface Temperature of Induction Machine

NASA Astrophysics Data System (ADS)

Mr., J. Ravi Kumar; Banakara, Basavaraja, Dr.

2017-08-01

This paper presents electromagnetic and thermal behavior of Induction Motor (IM) through the modeling and analysis by applying multiphysics coupled Finite Element Analysis (FEA). Therefore prediction of the magnetic flux, electromagnetic torque, stator and rotor losses and temperature distribution inside an operating electric motor are the most important issues during its design. Prediction and estimation of these parameters allows design engineers to decide capability of the machine for the proposed load, temperature rating and its application for which it is being designed ensuring normal motor operation at rated conditions. In this work, multiphysics coupled electromagnetic - thermal modeling and analysis of induction motor at rated and high frequency has carried out applying Arkkio’s torque method. COMSOL Multiphysics software is used for modeling and finite element analysis of IM. Transient electromagnetic torque, magnetic field distribution, speed-torque characteristics of IM were plotted and studied at different frequencies. This proposed work helps in the design and prediction of accurate performance of induction motor specific to various industrial drive applications. Results obtained are also validated with experimental analysis. The main purpose of this model is to use it as an integral part of the design aiming to system optimization of Variable Speed Drive (VSD) and its components using coupled simulations.

The rewritable effects of bonded magnet for large starting torque and high efficiency in the small power single-phase written pole motor

NASA Astrophysics Data System (ADS)

Choi, Jae-Hak; Lee, Sung-Ho

2009-04-01

This paper presents a single-phase written pole motor using a bonded ring magnet for the small power home application. The motor has an exciter pole structure inside the stator and hybrid characteristics of an induction motor and permanent magnet motor. The design parameters and operating characteristics of the hybrid concept motor are investigated to increase starting torque and efficiency, which is most important for the small power home application. Larger starting torque and higher efficiency than those of the conventional induction motor could be obtained by using the rewritable characteristics of bonded magnet on the starting and running conditions.

The Influence of Vacuum Circuit Breakers and Different Motor Models on Switching Overvoltages in Motor Circuits

NASA Astrophysics Data System (ADS)

Wong, Cat S. M.; Snider, L. A.; Lo, Edward W. C.; Chung, T. S.

Switching of induction motors with vacuum circuit breakers continues to be a concern. In this paper the influence on statistical overvoltages of the stochastic characteristics of vacuum circuit breakers, high frequency models of motors and transformers, and network characteristics, including cable lengths and network topology are evaluated and a general view of the overvoltages phenomena is presented. Finally, a real case study on the statistical voltage levels and risk-of-failure resulting from switching of a vacuum circuit breaker in an industrial installation in Hong Kong is presented.

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

Extended Constant Power Speed Range of the Brushless DC Motor Through Dual Mode Inverter Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawler, J.S.

2000-06-23

The trapezoidal back electromotive force (emf) brushless direct current (dc) motor (BDCM) with surface-mounted magnets has high-power density and efficiency especially when rare-earth magnet materials are used. Traction applications, such as electric vehicles, could benefit significantly from the use of such motors. Unfortunately, a practical means for driving the motor over a constant power speed ratio (CPSR) of 5:1 or more has not yet been developed. A key feature of these motors is that they have low internal inductance. The phase advance method is effective in controlling the motor power over such a speed range, but the current at highmore » speed may be several times greater than that required at the base speed. The increase in current during high-speed operation is due to the low motor inductance and the action of the bypass diodes of the inverter. The use of such a control would require increased current rating of the inverter semiconductors and additional cooling for the inverter, where the conduction losses increase proportionally with current, and especially for the motor, where the losses increase with the square of the current. The high current problems of phase advance can be mitigated by adding series inductance; however, this reduces power density, requires significant increase in supply voltage, and leaves the CPSR performance of the system highly sensitive to variations in the available voltage. A new inverter topology and control scheme has been developed that can drive low-inductance BDCMs over the CPSR that would be required in electric vehicle applications. This new controller is called the dual-mode inverter control (DMIC). It is shown that the BDCM has an infinite CPSR when it is driven by the DMIC.« less

Optimum Construction of Heating Coil for Domestic Induction Cooker

NASA Astrophysics Data System (ADS)

Sinha, Dola; Bandyopadhyay, Atanu; Sadhu, Pradip Kumar; Pal, Nitai

2010-10-01

The design and optimization of the parameters of heating coil is very important for the analytical analysis of high frequency inverter fed induction cooker. Moreover, accurate prediction of high frequency winding loss (i.e., losses due to skin and proximity effects) is necessary as the induction cooker used in power electronics applications. At high frequency current penetration in the induction coil circuit is very difficult for conducting wire due to skin-effect. To eradicate the skin effect heating coil is made up of bundle conductor i.e., litz wire. In this paper inductances and AC resistances of a litz-wire are calculated and optimized by considering the input parameters like wire type, shape, number of strand, number of spiral turn, number of twist per feet of heating coil and operating frequency. A high frequency half bridge series resonant mirror inverter circuit is used in this paper and taking the optimum values of inductance and ac resistance the circuit is simulated through PSPICE simulations. It has been noticed that the results are feasible enough for real implementation.

Features of Synchronous Electronically Commutated Motors in Servomotor Operation Modes

NASA Astrophysics Data System (ADS)

Dirba, J.; Lavrinovicha, L.; Dobriyan, R.

2017-04-01

The authors consider the features and operation specifics of the synchronous permanent magnet motors and the synchronous reluctance motors with electronic commutation in servomotor operation modes. Calculation results show that mechanical and control characteristics of studied motors are close to a linear shape. The studied motor control is proposed to implement similar to phase control of induction servomotor; it means that angle θ (angle between vectors of the supply voltage and non-load electromotive force) or angle ɛ (angle between rotor direct axis and armature magnetomotive force axis) is changed. The analysis results show that synchronous electronically commutated motors could be used as servomotors.

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.

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. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

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.

Lifecycle Analysis of Different Motors from the Standpoint of Environmental Impact

NASA Astrophysics Data System (ADS)

Orlova, S.; Rassõlkin, A.; Kallaste, A.; Vaimann, T.; Belahcen, A.

2016-12-01

Comparative analysis is performed for different motors from the standpoint of damage inflicted by them during their lifecycle. Three types of motors have been considered: the synchronous reluctance motor, the permanent magnet assisted synchronous reluctance motor and the induction motor. The assessment of lifecycle has been made in terms of its four stages: manufacturing, distribution, use and end of life. The results show that the production costs of synchronous reluctance motor are lower compared to that of permanent magnet assisted motors, but due to their low efficiency they exert the greatest environmental impact. The main conclusion is that the assessment made at the early designing stage for the related environmental impact enables its reduction.

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. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Rats fed soy protein isolate (SPI) have impaired hepatic CYP1A1 induction by polycyclic aromatic hydrocarbons as a result of interference with aryl hydrocarbon receptor signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singhal, Rohit; Badger, Thomas M.; Arkansas Children's Nutrition Center, Little Rock, AR 72202

2008-03-01

Consumption of soy diets has been found to reduce cancer incidence in animals and is associated with reduced cancer risk in humans. Previously, we have demonstrated that female Sprague-Dawley rats fed purified AIN-93G diets with soy protein isolate (SPI) as the sole protein source had reduced CYP1A1 induction and basal aryl hydrocarbon receptor (AhR) levels relative to those fed the same diet containing casein (CAS). In the present study, the molecular mechanisms underlying reduced AhR expression have been studied. The SPI-effect on AhR was not observed after feeding diets containing the purified soy isoflavones genistein or daidzein. Rat hepatoma FGC-4more » cells were treated with the serum obtained from rats fed CAS- or SPI-containing diets. Reduced AhR levels (P < 0.05) were observed after 24 h exposure to SPI-serum without any changes in the overall expression of chaperone proteins-HSP90 and XAP2. SPI-serum-stimulated AhR degradation was inhibited by treating the cells with the proteasome inhibitor, MG132, and was observed to be preceded by ubiquitination of the receptor. A reduced association of XAP2 with the immunoprecipitated AhR complex was observed. SPI-serum-mediated AhR degradation was preceded by nuclear translocation of the receptor. However, the translocated receptor was found to be unable to heterodimerize with ARNT or to bind to XRE elements on the CYP1A1 enhancer. These data suggest that feeding SPI-containing diets antagonizes AhR signaling by a novel mechanism which differs from those established for known AhR antagonists.« less

Fundamental Study on Saving Energy for Electrified Railway System Applying High Temperature Superconductor Motor and Energy Storage System

NASA Astrophysics Data System (ADS)

Konishi, Takeshi; Nakamura, Taketsune; Amemiya, Naoyuki

Induction motor instead of dc one has been applied widely for dc electric rolling stock because of the advantage of its utility and efficiency. However, further improvement of motor characteristics will be required to realize environment-friendly dc railway system in the future. It is important to study more efficient machine applying dc electric rolling stock for next generation high performance system. On the other hand, the methods to reuse regenerative energy produced by motors effectively are also important. Therefore, we carried out fundamental study on saving energy for electrified railway system. For the first step, we introduced the energy storage system applying electric double-layer capacitors (EDLC), and its control system. And then, we tried to obtain the specification of high temperature superconductor induction/synchronous motor (HTS-ISM), which performance is similar with that of the conventional induction motors. Furthermore, we tried to evaluate an electrified railway system applying energy storage system and HTS-ISM based on simulation. We succeeded in showing the effectiveness of the introductions of energy storage system and HTS-ISM in DC electrified railway system.

Impairments of long-term depression induction and motor coordination precede Aβ accumulation in the cerebellum of APPswe/PS1dE9 double transgenic mice.

PubMed

Kuwabara, Yuki; Ishizeki, Masato; Watamura, Naoto; Toba, Junya; Yoshii, Aya; Inoue, Takafumi; Ohshima, Toshio

2014-08-01

Alzheimer's disease (AD) is a neurodegenerative disorder that represents the most common type of dementia among elderly people. Amyloid beta (Aβ) peptides in extracellular Aβ plaques, produced from the amyloid precursor protein (APP) via sequential processing by β- and γ-secretases, impair hippocampal synaptic plasticity, and cause cognitive dysfunction in AD patients. Here, we report that Aβ peptides also impair another form of synaptic plasticity; cerebellar long-term depression (LTD). In the cerebellum of commonly used AD mouse model, APPswe/PS1dE9 mice, Aβ plaques were detected from 8 months and profound accumulation of Aβ plaques was observed at 18 onths of age. Biochemical analysis revealed relatively high levels of APP protein and Aβ in the cerebellum of APPswe/PS1dE9 mice. At pre-Aβ accumulation stage, LTD induction, and motor coordination are disturbed. These results indicate that soluble Aβ oligomers disturb LTD induction and cerebellar function in AD mouse model. © 2014 International Society for Neurochemistry.

Elevated carboxylesterase activity contributes to the lambda-cyhalothrin insensitivity in quercetin fed Helicoverpa armigera (Hübner).

PubMed

Chen, Chengyu; Liu, Ying; Shi, Xueyan; Desneux, Nicolas; Han, Peng; Gao, Xiwu

2017-01-01

Quercetin as one of the key plant secondary metabolite flavonol is ubiquitous in terrestrial plants. In this study, the decrease in sensitivity to lambda-cyhalothrin was observed in quercetin-fed Helicoverpa armigera larvae. In order to figure out the mechanisms underlying the decreased sensitivity of H. armigera larvae to lambda-cyhalothrin by quercetin induction, the changes in carboxylesterase activity and in-vitro hydrolytic metabolic capacity to lambda-cyhalothrin were examined. The LC50 value of quercetin-fed H. armigera larvae to lambda-cyhalothrin showed 2.41-fold higher than that of the control. S, S, S-Tributyl phosphorotrithioate (DEF) treatment showed a synergism effect on lambda-cyhalothrin toxicity to quercetin-fed H. armigera. Moreover, the activity of carboxylesterase was significantly higher in quercetin-fed H. armigera larvae after fed on quercetin for 48 h. The in-vitro hydrolytic metabolic capacity to lambda-cyhalothrin in quercetin-fed H. armigera larvae midgut was 289.82 nmol 3-PBA/mg protein/min, which is significant higher than that in the control group (149.60 nmol 3-PBA/mg protein/min). The elevated CarE enzyme activity and corresponding increased hydrolytic metabolic capacity to lambda-cyhalothrin in quercetin-fed H. armigera contributed to the enhanced tolerance to lambda-cyhalothrin.

Elevated carboxylesterase activity contributes to the lambda-cyhalothrin insensitivity in quercetin fed Helicoverpa armigera (Hübner)

PubMed Central

Chen, Chengyu; Liu, Ying; Desneux, Nicolas; Han, Peng; Gao, Xiwu

2017-01-01

Quercetin as one of the key plant secondary metabolite flavonol is ubiquitous in terrestrial plants. In this study, the decrease in sensitivity to lambda-cyhalothrin was observed in quercetin-fed Helicoverpa armigera larvae. In order to figure out the mechanisms underlying the decreased sensitivity of H. armigera larvae to lambda-cyhalothrin by quercetin induction, the changes in carboxylesterase activity and in-vitro hydrolytic metabolic capacity to lambda-cyhalothrin were examined. The LC50 value of quercetin-fed H. armigera larvae to lambda-cyhalothrin showed 2.41-fold higher than that of the control. S, S, S-Tributyl phosphorotrithioate (DEF) treatment showed a synergism effect on lambda-cyhalothrin toxicity to quercetin-fed H. armigera. Moreover, the activity of carboxylesterase was significantly higher in quercetin-fed H. armigera larvae after fed on quercetin for 48 h. The in-vitro hydrolytic metabolic capacity to lambda-cyhalothrin in quercetin-fed H. armigera larvae midgut was 289.82 nmol 3-PBA/mg protein/min, which is significant higher than that in the control group (149.60 nmol 3-PBA/mg protein/min). The elevated CarE enzyme activity and corresponding increased hydrolytic metabolic capacity to lambda-cyhalothrin in quercetin-fed H. armigera contributed to the enhanced tolerance to lambda-cyhalothrin. PMID:28817718

82. Interior of 41 valve house; the motor (in the ...

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

82. Interior of 4-1 valve house; the motor (in the center) powering the valve mechanism is a two horsepower, 60 cycle, 10.4 amp, 220 volt induction motor manufactured in 1910 by the Allis Chambers Company of Milwaukee, Wisconsin. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

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

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

PubMed

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.

Design and analysis of a new flux-intensifying permanent magnet brushless motor with multilayer flux barriers

NASA Astrophysics Data System (ADS)

Yang, Shen; Zhu, Xiaoyong; Xiang, Zixuan; Fan, Deyang; Wu, Wenye; Yin, Jianing

2017-05-01

This paper proposes a new flux-intensifying permanent magnet brushless motor for potential application in electric vehicles. The key of the proposed motor is to adopt the concept of flux-intensifying effect, thus the preferable flux-weakening ability and extended speed range can be achieved. The usage of segmented and relatively thinner permanent magnet (PM) in the proposed motor contributes to the increase of d-axis inductance Ld. In addition, the multilayer flux barriers along q-axis flux path will effectively decrease q-axis inductance Lq. As a result, the unique feature of Ld>Lq can be obtained, which is beneficial to extending the speed range of the proposed motor. Furthermore, the flux-intensifying effect can reduce the risk of irreversible demagnetization in PMs. The electromagnetic performances of the proposed motor are analyzed and investigated in details by using the finite element methods, which demonstrate the excellent flux-weakening capability and wide speed range can be achieved in the proposed FI-PMBL motor.

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

An adaptive supervisory sliding fuzzy cerebellar model articulation controller for sensorless vector-controlled induction motor drive systems.

PubMed

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

2015-03-25

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.

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

Induction of late LTP-like plasticity in the human motor cortex by repeated non-invasive brain stimulation.

PubMed

Monte-Silva, Katia; Kuo, Min-Fang; Hessenthaler, Silvia; Fresnoza, Shane; Liebetanz, David; Paulus, Walter; Nitsche, Michael A

2013-05-01

Non-invasive brain stimulation enables the induction of neuroplasticity in humans, however, with so far restricted duration of the respective cortical excitability modifications. Conventional anodal transcranial direct current stimulation (tDCS) protocols including one stimulation session induce NMDA receptor-dependent excitability enhancements lasting for about 1 h. We aimed to extend the duration of tDCS effects by periodic stimulation, consisting of two stimulation sessions, since periodic stimulation protocols are able to induce neuroplastic excitability alterations stable for days or weeks, termed late phase long term potentiation (l-LTP), in animal slice preparations. Since both, l-LTP and long term memory formation, require gene expression and protein synthesis, and glutamatergic receptor activity modifications, l-LTP might be a candidate mechanism for the formation of long term memory. The impact of two consecutive tDCS sessions on cortical excitability was probed in the motor cortex of healthy humans, and compared to that of a single tDCS session. The second stimulation was applied without an interval (temporally contiguous tDCS), during the after-effects of the first stimulation (during after-effects; 3, or 20 min interval), or after the after-effects of the first stimulation had vanished (post after-effects; 3 or 24 h interval). The during after-effects condition resulted in an initially reduced, but then relevantly prolonged excitability enhancement, which was blocked by an NMDA receptor antagonist. The other conditions resulted in an abolishment, or a calcium channel-dependent reversal of neuroplasticity. Repeated tDCS within a specific time window is able to induce l-LTP-like plasticity in the human motor cortex. Copyright © 2013 Elsevier Inc. All rights reserved.

Fractal dimension and fuzzy logic systems for broken rotor bar detection in induction motors at start-up and steady-state regimes

NASA Astrophysics Data System (ADS)

Amezquita-Sanchez, Juan P.; Valtierra-Rodriguez, Martin; Perez-Ramirez, Carlos A.; Camarena-Martinez, David; Garcia-Perez, Arturo; Romero-Troncoso, Rene J.

2017-07-01

Squirrel-cage induction motors (SCIMs) are key machines in many industrial applications. In this regard, the monitoring of their operating condition aiming at avoiding damage and reducing economical losses has become a demanding task for industry. In the literature, several techniques and methodologies to detect faults that affect the integrity and performance of SCIMs have been proposed. However, they have only been focused on analyzing either the start-up transient or the steady-state operation regimes, two common operating scenarios in real practice. In this work, a novel methodology for broken rotor bar (BRB) detection in SCIMs during both start-up and steady-state operation regimes is proposed. It consists of two main steps. In the first one, the analysis of three-axis vibration signals using fractal dimension (FD) theory is carried out. Since different FD-based algorithms can give different results, three algorithms named Katz’ FD, Higuchi’s FD, and box dimension, are tested. In the second step, a fuzzy logic system for each regime is presented for automatic diagnosis. To validate the proposal, a motor with different damage levels has been tested: one with a partially BRB, a second with one fully BRB, and the third with two BRBs. The obtained results demonstrate the proposed effectiveness.

Oral microbial profile discriminates breast-fed from formula-fed infants.

PubMed

Holgerson, Pernilla L; Vestman, Nelly R; Claesson, Rolf; Ohman, Carina; Domellöf, Magnus; Tanner, Anne C R; Hernell, Olle; Johansson, Ingegerd

2013-02-01

Little is known about the effect of diet on the oral microbiota of infants, although diet is known to affect the gut microbiota. The aims of the present study were to compare the oral microbiota in breast-fed and formula-fed infants, and investigate growth inhibition of streptococci by infant-isolated lactobacilli. A total of 207 mothers consented to participation of their 3-month-old infants. A total of 146 (70.5%) infants were exclusively and 38 (18.4%) partially breast-fed, and 23 (11.1%) were exclusively formula-fed. Saliva from all of their infants was cultured for Lactobacillus species, with isolate identifications from 21 infants. Lactobacillus isolates were tested for their ability to suppress Streptococcus mutans and S sanguinis. Oral swabs from 73 infants were analysed by the Human Oral Microbe Identification Microarray (HOMIM) and by quantitative polymerase chain reaction for Lactobacillus gasseri. Lactobacilli were cultured from 27.8% of exclusively and partially breast-fed infants, but not from formula-fed infants. The prevalence of 14 HOMIM-detected taxa, and total salivary lactobacilli counts differed by feeding method. Multivariate modelling of HOMIM-detected bacteria and possible confounders clustered samples from breast-fed infants separately from formula-fed infants. The microbiota of breast-fed infants differed based on vaginal or C-section delivery. Isolates of L plantarum, L gasseri, and L vaginalis inhibited growth of the cariogenic S mutans and the commensal S sanguinis: L plantarum >L gasseri >L vaginalis. The microbiota of the mouth differs between 3-month-old breast-fed and formula-fed infants. Possible mechanisms for microbial differences observed include species suppression by lactobacilli indigenous to breast milk.

Dynamic characteristics of motor-gear system under load saltations and voltage transients

NASA Astrophysics Data System (ADS)

Bai, Wenyu; Qin, Datong; Wang, Yawen; Lim, Teik C.

2018-02-01

In this paper, a dynamic model of a motor-gear system is proposed. The model combines a nonlinear permeance network model (PNM) of a squirrel-cage induction motor and a coupled lateral-torsional dynamic model of a planetary geared rotor system. The external excitations including voltage transients and load saltations, as well as the internal excitations such as spatial effects, magnetic circuits topology and material nonlinearity in the motor, and time-varying mesh stiffness and damping in the planetary gear system are considered in the proposed model. Then, the simulation results are compared with those predicted by the electromechanical model containing a dynamic motor model with constant inductances. The comparison showed that the electromechanical system model with the PNM motor model yields more reasonable results than the electromechanical system model with the lumped-parameter electric machine. It is observed that electromechanical coupling effect can induce additional and severe gear vibrations. In addition, the external conditions, especially the voltage transients, will dramatically affect the dynamic characteristics of the electromechanical system. Finally, some suggestions are offered based on this analysis for improving the performance and reliability of the electromechanical system.

Induction of olfaction and cancer-related genes in mice fed a high-fat diet as assessed through the mode-of-action by network identification analysis.

PubMed

Choi, Youngshim; Hur, Cheol-Goo; Park, Taesun

2013-01-01

The pathophysiological mechanisms underlying the development of obesity and metabolic diseases are not well understood. To gain more insight into the genetic mediators associated with the onset and progression of diet-induced obesity and metabolic diseases, we studied the molecular changes in response to a high-fat diet (HFD) by using a mode-of-action by network identification (MNI) analysis. Oligo DNA microarray analysis was performed on visceral and subcutaneous adipose tissues and muscles of male C57BL/6N mice fed a normal diet or HFD for 2, 4, 8, and 12 weeks. Each of these data was queried against the MNI algorithm, and the lists of top 5 highly ranked genes and gene ontology (GO)-annotated pathways that were significantly overrepresented among the 100 highest ranked genes at each time point in the 3 different tissues of mice fed the HFD were considered in the present study. The 40 highest ranked genes identified by MNI analysis at each time point in the different tissues of mice with diet-induced obesity were subjected to clustering based on their temporal patterns. On the basis of the above-mentioned results, we investigated the sequential induction of distinct olfactory receptors and the stimulation of cancer-related genes during the development of obesity in both adipose tissues and muscles. The top 5 genes recognized using the MNI analysis at each time point and gene cluster identified based on their temporal patterns in the peripheral tissues of mice provided novel and often surprising insights into the potential genetic mediators for obesity progression.

Differential Evolution Based IDWNN Controller for Fault Ride-Through of Grid-Connected Doubly Fed Induction Wind Generators

PubMed Central

Manonmani, N.; Subbiah, V.; Sivakumar, L.

2015-01-01

The key objective of wind turbine development is to ensure that output power is continuously increased. It is authenticated that wind turbines (WTs) supply the necessary reactive power to the grid at the time of fault and after fault to aid the flowing grid voltage. At this juncture, this paper introduces a novel heuristic based controller module employing differential evolution and neural network architecture to improve the low-voltage ride-through rate of grid-connected wind turbines, which are connected along with doubly fed induction generators (DFIGs). The traditional crowbar-based systems were basically applied to secure the rotor-side converter during the occurrence of grid faults. This traditional controller is found not to satisfy the desired requirement, since DFIG during the connection of crowbar acts like a squirrel cage module and absorbs the reactive power from the grid. This limitation is taken care of in this paper by introducing heuristic controllers that remove the usage of crowbar and ensure that wind turbines supply necessary reactive power to the grid during faults. The controller is designed in this paper to enhance the DFIG converter during the grid fault and this controller takes care of the ride-through fault without employing any other hardware modules. The paper introduces a double wavelet neural network controller which is appropriately tuned employing differential evolution. To validate the proposed controller module, a case study of wind farm with 1.5 MW wind turbines connected to a 25 kV distribution system exporting power to a 120 kV grid through a 30 km 25 kV feeder is carried out by simulation. PMID:26516636

Differential Evolution Based IDWNN Controller for Fault Ride-Through of Grid-Connected Doubly Fed Induction Wind Generators.

PubMed

Manonmani, N; Subbiah, V; Sivakumar, L

2015-01-01

The key objective of wind turbine development is to ensure that output power is continuously increased. It is authenticated that wind turbines (WTs) supply the necessary reactive power to the grid at the time of fault and after fault to aid the flowing grid voltage. At this juncture, this paper introduces a novel heuristic based controller module employing differential evolution and neural network architecture to improve the low-voltage ride-through rate of grid-connected wind turbines, which are connected along with doubly fed induction generators (DFIGs). The traditional crowbar-based systems were basically applied to secure the rotor-side converter during the occurrence of grid faults. This traditional controller is found not to satisfy the desired requirement, since DFIG during the connection of crowbar acts like a squirrel cage module and absorbs the reactive power from the grid. This limitation is taken care of in this paper by introducing heuristic controllers that remove the usage of crowbar and ensure that wind turbines supply necessary reactive power to the grid during faults. The controller is designed in this paper to enhance the DFIG converter during the grid fault and this controller takes care of the ride-through fault without employing any other hardware modules. The paper introduces a double wavelet neural network controller which is appropriately tuned employing differential evolution. To validate the proposed controller module, a case study of wind farm with 1.5 MW wind turbines connected to a 25 kV distribution system exporting power to a 120 kV grid through a 30 km 25 kV feeder is carried out by simulation.

A Principle and Winding Design of Consequent-Pole Bearingless Motors

NASA Astrophysics Data System (ADS)

Takenaga, Tomohiro; Kubota, Yutaka; Chiba, Akira; Fukao, Tadashi

Recently, bearingless motors have been developed to enhance motor drive systems with magnetic suspension. Several types of motors have been proposed as bearingless motors, such as induction, surface mounted permanent magnet, inset permanent magnet, interior permanent magnet, buried permanent magnet, homopolar, hybrid, and switched reluctance bearingless motors. Permanent magnet bearingless motors have been attracting more interests in these years because of the high efficiency. In this paper, a consequent-pole bearingless motor is proposed. A rotor has buried permanent magnets, of which polarities are like. The radial force of a consequent-pole bearingless motor is generated by dc current. Thus, rotational angular position is not needed in a magnetic suspension controller. Radial force variations caused by a rotor rotation are minimized by improving arrangement of stator suspension conductors. A prototype bearingless motor and its controller are built. In experiment, principles of magnetic suspension in the proposed consequent-pole bearingless drive are confirmed.

Using Induction to Refine Information Retrieval Strategies

NASA Technical Reports Server (NTRS)

Baudin, Catherine; Pell, Barney; Kedar, Smadar

1994-01-01

Conceptual information retrieval systems use structured document indices, domain knowledge and a set of heuristic retrieval strategies to match user queries with a set of indices describing the document's content. Such retrieval strategies increase the set of relevant documents retrieved (increase recall), but at the expense of returning additional irrelevant documents (decrease precision). Usually in conceptual information retrieval systems this tradeoff is managed by hand and with difficulty. This paper discusses ways of managing this tradeoff by the application of standard induction algorithms to refine the retrieval strategies in an engineering design domain. We gathered examples of query/retrieval pairs during the system's operation using feedback from a user on the retrieved information. We then fed these examples to the induction algorithm and generated decision trees that refine the existing set of retrieval strategies. We found that (1) induction improved the precision on a set of queries generated by another user, without a significant loss in recall, and (2) in an interactive mode, the decision trees pointed out flaws in the retrieval and indexing knowledge and suggested ways to refine the retrieval strategies.

Power-Factor Calculation under Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Seong T; Burress, Timothy A; Hsu, John S

2009-01-01

This paper introduces a new method for calculating the power factor with consideration of the cross saturation between the direct-axis (d-axis) and the quadrature-axis (q-axis) of an interior permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include the cross-saturation effect by adding the cross-coupled inductance terms. This paper also contains the new method of calculating the cross-coupled inductance values as well as self-inductance values in d- and q-axes. The analyzed motor is a high-speed brushless field excitation machine that offers high torque per ampere per core length at low speed and weakened flux at highmore » speed, which was developed for the traction motor of a hybrid electric vehicle.« less

Induction of plasticity in the human motor cortex by pairing an auditory stimulus with TMS.

PubMed

Sowman, Paul F; Dueholm, Søren S; Rasmussen, Jesper H; Mrachacz-Kersting, Natalie

2014-01-01

Acoustic stimuli can cause a transient increase in the excitability of the motor cortex. The current study leverages this phenomenon to develop a method for testing the integrity of auditorimotor integration and the capacity for auditorimotor plasticity. We demonstrate that appropriately timed transcranial magnetic stimulation (TMS) of the hand area, paired with auditorily mediated excitation of the motor cortex, induces an enhancement of motor cortex excitability that lasts beyond the time of stimulation. This result demonstrates for the first time that paired associative stimulation (PAS)-induced plasticity within the motor cortex is applicable with auditory stimuli. We propose that the method developed here might provide a useful tool for future studies that measure auditory-motor connectivity in communication disorders.

Cytokine and Chemokine Expression Associated with Steatohepatitis and Hepatocyte Proliferation in Rats Fed Ethanol Via Total Enteral Nutrition

USDA-ARS?s Scientific Manuscript database

Sprague-Dawley rats were intragastrically fed low carbohydrate-containing ethanol (EtOH) diets via total enteral nutrition for up to 49 d. Induction of EtOH metabolism and appearance of steatosis preceded development of oxidative stress, inflammation, and cell death. A transitory peak of tumor necro...

Role of protein kinase C in the induction and maintenance of serotonin-dependent enhancement of the glutamate response in isolated siphon motor neurons of Aplysia californica.

PubMed

Villareal, Greg; Li, Quan; Cai, Diancai; Fink, Ann E; Lim, Travis; Bougie, Joanna K; Sossin, Wayne S; Glanzman, David L

2009-04-22

Serotonin (5-HT) mediates learning-related facilitation of sensorimotor synapses in Aplysia californica. Under some circumstances 5-HT-dependent facilitation requires the activity of protein kinase C (PKC). One critical site of PKC's contribution to 5-HT-dependent synaptic facilitation is the presynaptic sensory neuron. Here, we provide evidence that postsynaptic PKC also contributes to synaptic facilitation. We investigated the contribution of PKC to enhancement of the glutamate-evoked potential (Glu-EP) in isolated siphon motor neurons in cell culture. A 10 min application of either 5-HT or phorbol ester, which activates PKC, produced persistent (> 50 min) enhancement of the Glu-EP. Chelerythrine and bisindolylmaleimide-1 (Bis), two inhibitors of PKC, both blocked the induction of 5-HT-dependent enhancement. An inhibitor of calpain, a calcium-dependent protease, also blocked 5-HT's effect. Interestingly, whereas chelerythrine blocked maintenance of the enhancement, Bis did not. Because Bis has greater selectivity for conventional and novel isoforms of PKC than for atypical isoforms, this result implicates an atypical isoform in the maintenance of 5-HT's effect. Although induction of enhancement of the Glu-EP requires protein synthesis (Villareal et al., 2007), we found that maintenance of the enhancement does not. Maintenance of 5-HT-dependent enhancement appears to be mediated by a PKM-type fragment generated by calpain-dependent proteolysis of atypical PKC. Together, our results suggest that 5-HT treatment triggers two phases of PKC activity within the motor neuron, an early phase that may involve conventional, novel or atypical isoforms of PKC, and a later phase that selectively involves an atypical isoform.

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.

An inductance Fourier decomposition-based current-hysteresis control strategy for switched reluctance motors

NASA Astrophysics Data System (ADS)

Hua, Wei; Qi, Ji; Jia, Meng

2017-05-01

Switched reluctance machines (SRMs) have attracted extensive attentions due to the inherent advantages, including simple and robust structure, low cost, excellent fault-tolerance and wide speed range, etc. However, one of the bottlenecks limiting the SRMs for further applications is its unfavorable torque ripple, and consequently noise and vibration due to the unique doubly-salient structure and pulse-current-based power supply method. In this paper, an inductance Fourier decomposition-based current-hysteresis-control (IFD-CHC) strategy is proposed to reduce torque ripple of SRMs. After obtaining a nonlinear inductance-current-position model based Fourier decomposition, reference currents can be calculated by reference torque and the derived inductance model. Both the simulations and experimental results confirm the effectiveness of the proposed strategy.

Periconceptional Folic Acid Supplementation Benefit to Development of Early Sensory-Motor Function through Increase DNA Methylation in Rat Offspring

PubMed Central

Li, Wen; Li, Zhenshu; Li, Shou; Wang, Xinyan; Wilson, John X.; Huang, Guowei

2018-01-01

Periconceptional maternal folate levels may alter DNA methylation patterns and health outcomes in offspring. We hypothesized that maternal folic acid supplementation alters fetal neural development through DNA methylation in the fetal brain. Twenty-eight rats were randomly assigned to four groups: three groups of the female rats were fed folate-normal, folate-deficient or folate-supplemented diets from seven days before mating to delivery. In another group, folic acid supplementation diet short-period group was fed a folate-normal diet, except for 10 days (begin mating) when this group was fed a folate-supplemented diet. After delivery, the diets were changed to folate-normal diet for all four groups. The cliff avoidance and forelimb grip tests were used to assess sensory motor function of rat offspring. The results indicate that maternal folic acid supplementation improved the early development of sensory-motor function in offspring. Maternal folic acid supplementation increased the methylation potential, global DNA methylation (5-mC) and DNA methyltransferase expression and activity in the brains of the offspring. In conclusion, maternal folic acid supplementation increases DNA methylation pattern in offspring brain and improves the early development of sensory-motor function. PMID:29494536

Simple Motor Control Concept Results High Efficiency at High Velocities

NASA Astrophysics Data System (ADS)

Starin, Scott; Engel, Chris

2013-09-01

The need for high velocity motors in space applications for reaction wheels and detectors has stressed the limits of Brushless Permanent Magnet Motors (BPMM). Due to inherent hysteresis core losses, conventional BPMMs try to balance the need for torque verses hysteresis losses. Cong-less motors have significantly less hysteresis losses but suffer from lower efficiencies. Additionally, the inherent low inductance in cog-less motors result in high ripple currents or high switching frequencies, which lowers overall efficiency and increases performance demands on the control electronics.However, using a somewhat forgotten but fully qualified technology of Isotropic Magnet Motors (IMM), extremely high velocities may be achieved at low power input using conventional drive electronics. This paper will discuss the trade study efforts and empirical test data on a 34,000 RPM IMM.

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. Copyright © 2015. Published by Elsevier Ltd.

An Enhanced Three-Level Voltage Switching State Scheme for Direct Torque Controlled Open End Winding Induction Motor

NASA Astrophysics Data System (ADS)

Kunisetti, V. Praveen Kumar; Thippiripati, Vinay Kumar

2018-01-01

Open End Winding Induction Motors (OEWIM) are popular for electric vehicles, ship propulsion applications due to less DC link voltage. Electric vehicles, ship propulsions require ripple free torque. In this article, an enhanced three-level voltage switching state scheme for direct torque controlled OEWIM drive is implemented to reduce torque and flux ripples. The limitations of conventional Direct Torque Control (DTC) are: possible problems during low speeds and starting, it operates with variable switching frequency due to hysteresis controllers and produces higher torque and flux ripple. The proposed DTC scheme can abate the problems of conventional DTC with an enhanced voltage switching state scheme. The three-level inversion was obtained by operating inverters with equal DC-link voltages and it produces 18 voltage space vectors. These 18 vectors are divided into low and high frequencies of operation based on rotor speed. The hardware results prove the validity of proposed DTC scheme during steady-state and transients. From simulation and experimental results, proposed DTC scheme gives less torque and flux ripples on comparison to two-level DTC. The proposed DTC is implemented using dSPACE DS-1104 control board interface with MATLAB/SIMULINK-RTI model.

An Enhanced Three-Level Voltage Switching State Scheme for Direct Torque Controlled Open End Winding Induction Motor

NASA Astrophysics Data System (ADS)

Kunisetti, V. Praveen Kumar; Thippiripati, Vinay Kumar

2018-06-01

Open End Winding Induction Motors (OEWIM) are popular for electric vehicles, ship propulsion applications due to less DC link voltage. Electric vehicles, ship propulsions require ripple free torque. In this article, an enhanced three-level voltage switching state scheme for direct torque controlled OEWIM drive is implemented to reduce torque and flux ripples. The limitations of conventional Direct Torque Control (DTC) are: possible problems during low speeds and starting, it operates with variable switching frequency due to hysteresis controllers and produces higher torque and flux ripple. The proposed DTC scheme can abate the problems of conventional DTC with an enhanced voltage switching state scheme. The three-level inversion was obtained by operating inverters with equal DC-link voltages and it produces 18 voltage space vectors. These 18 vectors are divided into low and high frequencies of operation based on rotor speed. The hardware results prove the validity of proposed DTC scheme during steady-state and transients. From simulation and experimental results, proposed DTC scheme gives less torque and flux ripples on comparison to two-level DTC. The proposed DTC is implemented using dSPACE DS-1104 control board interface with MATLAB/SIMULINK-RTI model.

Enhancement of Oral Tolerance Induction in DO11.10 Mice by Lactobacillus gasseri OLL2809 via Increase of Effector Regulatory T Cells.

PubMed

Aoki-Yoshida, Ayako; Yamada, Kiyoshi; Hachimura, Satoshi; Sashihara, Toshihiro; Ikegami, Shuji; Shimizu, Makoto; Totsuka, Mamoru

2016-01-01

Food allergy is a serious problem for infants and young children. Induction of antigen-specific oral tolerance is one therapeutic strategy. Enhancement of oral tolerance induction by diet is a promising strategy to prevent food allergy in infants. Thus, in this study, we evaluate the effect of probiotic Lactobacillus gasseri OLL2809 (LG2809) on oral tolerance induction in a mouse model. The degree of oral tolerance induction was evaluated by measuring the proliferation and level of IL-2 production of splenic CD4+ T cells from DO11.10 mice fed ovalbumin (OVA) alone or OVA with LG2809. Oral administration of LG2809 significantly decreased the rate of proliferation and IL-2 production by CD4+ T cells from OVA-fed mice. LG2809 increased a ratio of CD4+ T-cell population, producing high levels of IL-10 and having strong suppressive activity. Moreover, LG2809 increased a ratio of plasmacytoid dendritic cells (pDCs) among the lamina propria (LP) in small intestine. When used as antigen presenting cells to naïve CD4+ T cells from DO11.10 mice, LP cells from BALB/c mice fed LG2809 induced higher IL-10 production and stronger suppressive activity than those from non-treated mice. These results suggest that oral administration of LG2809 increases the population of pDCs in the LP, resulting in the enhancement of oral tolerance induction by increasing the ratio of effector regulatory T cells. LG2809 could, therefore, act as a potent immunomodulator to prevent food allergies by promoting oral tolerance.

Self-regulation of primary motor cortex activity with motor imagery induces functional connectivity modulation: A real-time fMRI neurofeedback study.

PubMed

Makary, Meena M; Seulgi, Eun; Kyungmo Park

2017-07-01

Recent developments in data acquisition of functional magnetic resonance imaging (fMRI) have led to rapid preprocessing and analysis of brain activity in a quasireal-time basis, what so called real-time fMRI neurofeedback (rtfMRI-NFB). This information is fed back to subjects allowing them to gain a voluntary control over their own region-specific brain activity. Forty-one healthy participants were randomized into an experimental (NFB) group, who received a feedback directly proportional to their brain activity from the primary motor cortex (M1), and a control (CTRL) group who received a sham feedback. The M1 ROI was functionally localized during motor execution and imagery tasks. A resting-state functional run was performed before and after the neurofeedback training to investigate the default mode network (DMN) modulation after training. The NFB group revealed increased DMN functional connectivity after training to the cortical and subcortical sensory/motor areas (M1/S1 and caudate nucleus, respectively), which may be associated with sensorimotor processing of learning in the resting state. These results show that motor imagery training through rtfMRI-NFB could modulate the DMN functional connectivity to motor-related areas, suggesting that this modulation potentially subserved the establishment of motor learning in the NFB group.

Induction of cortical plasticity and improved motor performance following unilateral and bilateral transcranial direct current stimulation of the primary motor cortex.

PubMed

Kidgell, Dawson J; Goodwill, Alicia M; Frazer, Ashlyn K; Daly, Robin M

2013-07-01

Transcranial direct current stimulation (tDCS) is a non-invasive technique that modulates the excitability of neurons within the primary motor cortex (M1). Research shows that anodal-tDCS applied over the non-dominant M1 (i.e. unilateral stimulation) improves motor function of the non-dominant hand. Similarly, previous studies also show that applying cathodal tDCS over the dominant M1 improves motor function of the non-dominant hand, presumably by reducing interhemispheric inhibition. In the present study, one condition involved anodal-tDCS over the non-dominant M1 (unilateral stimulation) whilst a second condition involved applying cathodal-tDCS over the dominant M1 and anodal-tDCS over non-dominant M1 (bilateral stimulation) to determine if unilateral or bilateral stimulation differentially modulates motor function of the non-dominant hand. Using a randomized, cross-over design, 11 right-handed participants underwent three stimulation conditions: 1) unilateral stimulation, that involved anodal-tDCS applied over the non-dominant M1, 2) bilateral stimulation, whereby anodal-tDCS was applied over the non-dominant M1, and cathodal-tDCS over the dominant M1, and 3) sham stimulation. Transcranial magnetic stimulation (TMS) was performed before, immediately after, 30 and 60 minutes after stimulation to elucidate the neural mechanisms underlying any potential after-effects on motor performance. Motor function was evaluated by the Purdue pegboard test. There were significant improvements in motor function following unilateral and bilateral stimulation when compared to sham stimulation at all-time points (all P < 0.05); however there was no difference across time points between unilateral and bilateral stimulation. There was also a similar significant increase in corticomotor excitability with both unilateral and bilateral stimulation immediately post, 30 minutes and 60 minutes compared to sham stimulation (all P < 0.05). Unilateral and bilateral stimulation reduced short

The Establishment of Metabolic Syndrome Model by Induction of Fructose Drinking Water in Male Wistar Rats

PubMed Central

Thent, Zar Chi; Sapri, Shaiful Ridzwan; Sahruddin, Natasya Nadia; Mohd Yusof, Mohd Rafizul; Haji Suhaimi, Farihah

2014-01-01

Background. Metabolic syndrome can be caused by modification of diet by means of consumption of high carbohydrate and high fat diet such as fructose. Aims. To develop a metabolic syndrome rat model by induction of fructose drinking water (FDW) in male Wistar rats. Methods. Eighteen male Wistar rats were fed with FDW 20% and FDW 25% for a duration of eight weeks. The physiological changes with regard to food and fluid intake, as well as calorie intake, were measured. The metabolic changes such as obesity, dyslipidaemia, hypertension, and hyperglycaemia were determined. Data was presented in mean ± SEM subjected to one-way ANOVA. Results. Male Wistar rats fed with FDW 20% for eight weeks developed significant higher obesity parameters compared to those fed with FDW 25%. There was hypertrophy of adipocytes in F20 and F25. There were also systolic hypertension, hypertriglyceridemia, and hyperglycemia in both groups. Conclusion. We conclude that the metabolic syndrome rat model is best established with the induction of FDW 20% for eight weeks. This was evident in the form of higher obesity parameter which caused the development of the metabolic syndrome. PMID:25045660

Online Detection of Broken Rotor Bar Fault in Induction Motors by Combining Estimation of Signal Parameters via Min-norm Algorithm and Least Square Method

NASA Astrophysics Data System (ADS)

Wang, Pan-Pan; Yu, Qiang; Hu, Yong-Jun; Miao, Chang-Xin

2017-11-01

Current research in broken rotor bar (BRB) fault detection in induction motors is primarily focused on a high-frequency resolution analysis of the stator current. Compared with a discrete Fourier transformation, the parametric spectrum estimation technique has a higher frequency accuracy and resolution. However, the existing detection methods based on parametric spectrum estimation cannot realize online detection, owing to the large computational cost. To improve the efficiency of BRB fault detection, a new detection method based on the min-norm algorithm and least square estimation is proposed in this paper. First, the stator current is filtered using a band-pass filter and divided into short overlapped data windows. The min-norm algorithm is then applied to determine the frequencies of the fundamental and fault characteristic components with each overlapped data window. Next, based on the frequency values obtained, a model of the fault current signal is constructed. Subsequently, a linear least squares problem solved through singular value decomposition is designed to estimate the amplitudes and phases of the related components. Finally, the proposed method is applied to a simulated current and an actual motor, the results of which indicate that, not only parametric spectrum estimation technique.

Wireless Monitoring of Induction Machine Rotor Physical Variables.

PubMed

Doolan Fernandes, Jefferson; Carvalho Souza, Francisco Elvis; Cipriano Maniçoba, Glauco George; Salazar, Andrés Ortiz; de Paiva, José Alvaro

2017-11-18

With the widespread use of electric machines, there is a growing need to extract information from the machines to improve their control systems and maintenance management. The present work shows the development of an embedded system to perform the monitoring of the rotor physical variables of a squirrel cage induction motor. The system is comprised of: a circuit to acquire desirable rotor variable(s) and value(s) that send it to the computer; a rectifier and power storage circuit that converts an alternating current in a continuous current but also stores energy for a certain amount of time to wait for the motor's shutdown; and a magnetic generator that harvests energy from the rotating field to power the circuits mentioned above. The embedded system is set on the rotor of a 5 HP squirrel cage induction motor, making it difficult to power the system because it is rotating. This problem can be solved with the construction of a magnetic generator device to avoid the need of using batteries or collector rings and will send data to the computer using a wireless NRF24L01 module. For the proposed system, initial validation tests were made using a temperature sensor (DS18b20), as this variable is known as the most important when identifying the need for maintenance and control systems. Few tests have shown promising results that, with further improvements, can prove the feasibility of using sensors in the rotor.

Dynamic characteristic of electromechanical coupling effects in motor-gear system

NASA Astrophysics Data System (ADS)

Bai, Wenyu; Qin, Datong; Wang, Yawen; Lim, Teik C.

2018-06-01

Dynamic characteristics of an electromechanical model which combines a nonlinear permeance network model (PNM) of a squirrel-cage induction motor and a coupled lateral-torsional dynamic model of a planetary geared rotor system is analyzed in this study. The simulations reveal the effects of internal excitations or parameters like machine slotting, magnetic saturation, time-varying mesh stiffness and shaft stiffness on the system dynamics. The responses of the electromechanical system with PNM motor model are compared with those responses of the system with dynamic motor model. The electromechanical coupling due to the interactions between the motor and gear system are studied. Furthermore, the frequency analysis of the electromechanical system dynamic characteristics predicts an efficient way to detect work condition of unsymmetrical voltage sag.

Research and simulation of the decoupling transformation in AC motor vector control

NASA Astrophysics Data System (ADS)

He, Jiaojiao; Zhao, Zhongjie; Liu, Ken; Zhang, Yongping; Yao, Tuozhong

2018-04-01

Permanent magnet synchronous motor (PMSM) is a nonlinear, strong coupling, multivariable complex object, and transformation decoupling can solve the coupling problem of permanent magnet synchronous motor. This paper gives a permanent magnet synchronous motor (PMSM) mathematical model, introduces the permanent magnet synchronous motor vector control coordinate transformation in the process of modal matrix inductance matrix transform through the matrix related knowledge of different coordinates of diagonalization, which makes the coupling between the independent, realize the control of motor current and excitation the torque current coupling separation, and derived the coordinate transformation matrix, the thought to solve the coupling problem of AC motor. Finally, in the Matlab/Simulink environment, through the establishment and combination between the PMSM ontology, coordinate conversion module, built the simulation model of permanent magnet synchronous motor vector control, introduces the model of each part, and analyzed the simulation results.

Reactive power generation in high speed induction machines by continuously occurring space-transients

NASA Astrophysics Data System (ADS)

Laithwaite, E. R.; Kuznetsov, S. B.

1980-09-01

A new technique of continuously generating reactive power from the stator of a brushless induction machine is conceived and tested on a 10-kw linear machine and on 35 and 150 rotary cage motors. An auxiliary magnetic wave traveling at rotor speed is artificially created by the space-transient attributable to the asymmetrical stator winding. At least two distinct windings of different pole-pitch must be incorporated. This rotor wave drifts in and out of phase repeatedly with the stator MMF wave proper and the resulting modulation of the airgap flux is used to generate reactive VA apart from that required for magnetization or leakage flux. The VAR generation effect increases with machine size, and leading power factor operation of the entire machine is viable for large industrial motors and power system induction generators.

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

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.

Cortical oscillatory activity and the induction of plasticity in the human motor cortex.

PubMed

McAllister, Suzanne M; Rothwell, John C; Ridding, Michael C

2011-05-01

Repetitive transcranial magnetic stimulation paradigms such as continuous theta burst stimulation (cTBS) induce long-term potentiation- and long-term depression-like plasticity in the human motor cortex. However, responses to cTBS are highly variable and may depend on the activity of the cortex at the time of stimulation. We investigated whether power in different electroencephalogram (EEG) frequency bands predicted the response to subsequent cTBS, and conversely whether cTBS had after-effects on the EEG. cTBS may utilize similar mechanisms of plasticity to motor learning; thus, we conducted a parallel set of experiments to test whether ongoing electroencephalography could predict performance of a visuomotor training task, and whether training itself had effects on the EEG. Motor evoked potentials (MEPs) provided an index of cortical excitability pre- and post-intervention. The EEG was recorded over the motor cortex pre- and post-intervention, and power spectra were computed. cTBS reduced MEP amplitudes; however, baseline power in the delta, theta, alpha or beta frequencies did not predict responses to cTBS or learning of the visuomotor training task. cTBS had no effect on delta, theta, alpha or beta power. In contrast, there was an increase in alpha power following visuomotor training that was positively correlated with changes in MEP amplitude post-training. The results suggest that the EEG is not a useful state-marker for predicting responses to plasticity-inducing paradigms. The correlation between alpha power and changes in corticospinal excitability following visuomotor training requires further investigation, but may be related to disengagement of the somatosensory system important for motor memory consolidation. © 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Novel permanent magnet linear motor with isolated movers: analytical, numerical and experimental study.

PubMed

Yan, Liang; Peng, Juanjuan; Jiao, Zongxia; Chen, Chin-Yin; Chen, I-Ming

2014-10-01

This paper proposes a novel permanent magnet linear motor possessing two movers and one stator. The two movers are isolated and can interact with the stator poles to generate independent forces and motions. Compared with conventional multiple motor driving system, it helps to increase the system compactness, and thus improve the power density and working efficiency. The magnetic field distribution is obtained by using equivalent magnetic circuit method. Following that, the formulation of force output considering armature reaction is carried out. Then inductances are analyzed with finite element method to investigate the relationships of the two movers. It is found that the mutual-inductances are nearly equal to zero, and thus the interaction between the two movers is negligible. A research prototype of the linear motor and a measurement apparatus on thrust force have been developed. Both numerical computation and experiment measurement are conducted to validate the analytical model of thrust force. Comparison shows that the analytical model matches the numerical and experimental results well.

Music supported therapy promotes motor plasticity in individuals with chronic stroke.

PubMed

Ripollés, P; Rojo, N; Grau-Sánchez, J; Amengual, J L; Càmara, E; Marco-Pallarés, J; Juncadella, M; Vaquero, L; Rubio, F; Duarte, E; Garrido, C; Altenmüller, E; Münte, T F; Rodríguez-Fornells, A

2016-12-01

Novel rehabilitation interventions have improved motor recovery by induction of neural plasticity in individuals with stroke. Of these, Music-supported therapy (MST) is based on music training designed to restore motor deficits. Music training requires multimodal processing, involving the integration and co-operation of visual, motor, auditory, affective and cognitive systems. The main objective of this study was to assess, in a group of 20 individuals suffering from chronic stroke, the motor, cognitive, emotional and neuroplastic effects of MST. Using functional magnetic resonance imaging (fMRI) we observed a clear restitution of both activity and connectivity among auditory-motor regions of the affected hemisphere. Importantly, no differences were observed in this functional network in a healthy control group, ruling out possible confounds such as repeated imaging testing. Moreover, this increase in activity and connectivity between auditory and motor regions was accompanied by a functional improvement of the paretic hand. The present results confirm MST as a viable intervention to improve motor function in chronic stroke individuals.

A review and comparison of fault detection and diagnosis methods for squirrel-cage induction motors: State of the art.

PubMed

Liu, Yiqi; Bazzi, Ali M

2017-09-01

Preventing induction motors (IMs) from failure and shutdown is important to maintain functionality of many critical loads in industry and commerce. This paper provides a comprehensive review of fault detection and diagnosis (FDD) methods targeting all the four major types of faults in IMs. Popular FDD methods published up to 2010 are briefly introduced, while the focus of the review is laid on the state-of-the-art FDD techniques after 2010, i.e. in 2011-2015 and some in 2016. Different FDD methods are introduced and classified into four categories depending on their application domains, instead of on fault types like in many other reviews, to better reveal hidden connections and similarities of different FDD methods. Detailed comparisons of the reviewed papers after 2010 are given in tables for fast referring. Finally, a dedicated discussion session is provided, which presents recent developments, trends and remaining difficulties regarding to FDD of IMs, to inspire novel research ideas and new research possibilities. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Introducing the Filtered Park's and Filtered Extended Park's Vector Approach to detect broken rotor bars in induction motors independently from the rotor slots number

NASA Astrophysics Data System (ADS)

Gyftakis, Konstantinos N.; Marques Cardoso, Antonio J.; Antonino-Daviu, Jose A.

2017-09-01

The Park's Vector Approach (PVA), together with its variations, has been one of the most widespread diagnostic methods for electrical machines and drives. Regarding the broken rotor bars fault diagnosis in induction motors, the common practice is to rely on the width increase of the Park's Vector (PV) ring and then apply some more sophisticated signal processing methods. It is shown in this paper that this method can be unreliable and is strongly dependent on the magnetic poles and rotor slot numbers. To overcome this constraint, the novel Filtered Park's/Extended Park's Vector Approach (FPVA/FEPVA) is introduced. The investigation is carried out with FEM simulations and experimental testing. The results prove to satisfyingly coincide, whereas the proposed advanced FPVA method is desirably reliable.

Minocycline increases the life span and motor activity and decreases lipid peroxidation in manganese treated Drosophila melanogaster.

PubMed

Bonilla, E; Contreras, R; Medina-Leendertz, S; Mora, M; Villalobos, V; Bravo, Y

2012-03-29

The objective of this study was to investigate the effect of Minocycline in the life span, motor activity, and lipid peroxidation of Drosophila melanogaster treated with manganese. Two days after emerging from the pupa male wild-type D. melanogaster were fed for 13 days with corn media containing 15 mM manganese. Then, they were divided in six groups of 300 flies each: group (a) remained treated with manganese (Mn group); group (b) began treatment with Minocycline (0.05 mM) (Mn-Minocycline group); group (c) received no additional treatment (Mn-no treatment group); group (d) simultaneously fed with manganese and Minocycline (Mn+Minocycline group). Additionally, a control (group e) with no treatment and another group (f) fed only with Minocycline after emerging from the pupa were added. All the manganese treated flies (group a) were dead on the 25th day. The life span in group f (101.66±1.33 days, mean S.E.M.) and of group b (97.00±3.46 days) were similar, but in both cases it was significantly higher than in group e (68.33±1.76 days), group c (67.05±2.30 days) and in those of group d (37.33±0.88). Manganese (groups a and d) decreased motor activity in D. melanogaster. In the Minocycline fed flies (groups b and f) a higher motor activity was detected. In Mn-Minocycline and Mn+Minocycline treated flies a significant decrease of MDA levels was detected when compared to the Minocycline group indicating that Minocycline and Mn appear to have a synergistic effect. In conclusion, Minocycline increased the life span and motor activity and decreased MDA formation of manganese treated D. melanogaster, probably by an inhibition of the production of reactive oxygen species. Manganese also exerted an antioxidant effect as shown by the significant decrease of MDA levels when compared to control flies. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Extending the Constant Power Speed Range of the Brushless DC Motor through Dual Mode Inverter Control -- Part I: Theory and Simulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawler, J.S.

2001-10-29

An inverter topology and control scheme has been developed that can drive low-inductance, surface-mounted permanent magnet motors over the wide constant power speed range required in electric vehicle applications. This new controller is called the dual-mode inverter control (DMIC) [1]. The DMIC can drive either the Permanent Magnet Synchronous Machine (PMSM) with sinusoidal back emf, or the brushless dc machine (BDCM) with trapezoidal emf in the motoring and regenerative braking modes. In this paper we concentrate on the BDCM under high-speed motoring conditions. Simulation results show that if all motor and inverter loss mechanisms are neglected, the constant power speedmore » range of the DMIC is infinite. The simulation results are supported by closed form expressions for peak and rms motor current and average power derived from analytical solution to the differential equations governing the DMIC/BDCM drive for the lossless case. The analytical solution shows that the range of motor inductance that can be accommodated by the DMIC is more than an order of magnitude such that the DMIC is compatible with both low- and high-inductance BDCMs. Finally, method is given for integrating the classical hysteresis band current control, used for motor control below base speed, with the phase advance of DMIC that is applied above base speed. The power versus speed performance of the DMIC is then simulated across the entire speed range.« less

Motor cortex plasticity can indicate vulnerability to motor fluctuation and high L-DOPA need in drug-naïve Parkinson's disease.

PubMed

Kishore, Asha; James, Praveen; Krishnan, Syam; Yahia-Cherif, Lydia; Meunier, Sabine; Popa, Traian

2017-02-01

Motor cortex plasticity is reported to be decreased in Parkinson's disease in studies which pooled patients in various stages of the disease. Whether the early decrease in plasticity is related to the motor signs or is linked to the future development of motor complications of treatment is unclear. The aim of the study was to test if motor cortex plasticity and its cerebellar modulation are impaired in treatment-naïve Parkinson's disease, are related to the motor signs of the disease and predict occurrence of motor complications of treatment. Twenty-nine denovo patients with Parkinson's disease were longitudinally assessed for motor complications for four years. Using transcranial magnetic stimulation, the plasticity of the motor cortex and its cerebellar modulation were measured (response to paired-associative stimulation alone or preceded by 2 active cerebellar stimulation protocols), both in the untreated state and after a single dose of L-DOPA. Twenty-six matched, healthy volunteers were tested, only without L-DOPA. Patients and healthy controls had similar proportions of responders and non-responders to plasticity induction. In the untreated state, the more efficient was the cerebellar modulation of motor cortex plasticity, the lower were the bradykinesia and rigidity scores. The extent of the individual plastic response to paired associative stimulation could indicate a vulnerability to develop early motor fluctuation but not dyskinesia. Measuring motor cortex plasticity in denovo Parkinson's disease could be a neurophysiological parameter that may help identify patients with greater propensity for early motor fluctuations. Copyright © 2016 Elsevier Ltd. All rights reserved.

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.

Rhythmic entrainment as a musical affect induction mechanism.

PubMed

J Trost, W; Labbé, C; Grandjean, D

2017-02-01

One especially important feature of metrical music is that it contains periodicities that listeners' bodily rhythms can adapt to. Recent psychological frameworks have introduced the notion of rhythmic entrainment, among other mechanisms, as an emotion induction principle. In this review paper, we discuss rhythmic entrainment as an affect induction mechanism by differentiating four levels of entrainment in humans-perceptual, autonomic physiological, motor, and social-all of which could contribute to a subjective feeling component. We review the theoretical and empirical literature on rhythmic entrainment to music that supports the existence of these different levels of entrainment by describing the phenomena and characterizing the associated underlying brain processes. The goal of this review is to present the theoretical implications and empirical findings about rhythmic entrainment as an important principle at the basis of affect induction via music, since it rests upon the temporal dimension of music, which is a specificity of music as an affective stimulus. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Removal of hexavalent chromium from wastewater using PPy/Fe3O4 magnetic nanocomposite influenced by rotating magnetic field from two pole three-phase induction motor

NASA Astrophysics Data System (ADS)

Aigbe, U. O.; Ho, W. H.; Maity, A.; Khenfouch, M.; Srinivasu, V.

2018-03-01

The influence of varying rotating magnetic field using a 2-pole three-phase induction motor on the removal of hexavalent chromium ions from wastewater using polypyrrole magnetic nanocomposite was explored in this study. Hexavalent chromium removal in this study was observed to be pH dependent under the influence of rotating magnetic field, as the percentage removal of hexavalent chromium decreased with increase in pH. The percentage amount of hexavalent chromium ions removed from the aqueous solution increased as the rotating magnetic field intensity was increased from 8.96-12.15 mT in the anticlockwise direction and 10.10-13.38 mT in the clockwise direction with maximum removals of 73% and 81% observed.

Plasticity of cortical inhibition in dystonia is impaired after motor learning and Paired-Associative Stimulation

PubMed Central

Meunier, Sabine; Russmann, Heike; Shamim, Ejaz; Lamy, Jean-Charles; Hallett, Mark

2012-01-01

Summary Artificial induction of plasticity by paired associative stimulation (PAS) in healthy subjects (HV) demonstrates Hebbian-like plasticity in selected inhibitory networks as well as excitatory ones. In a group of 17 patients with focal hand dystonia and a group of 19 HV, we evaluated how PAS and the learning of a simple motor task influence the circuits supporting long interval intracortical inhibition (LICI, reflecting activity of GABAB interneurons) and long latency afferent inhibition (LAI, reflecting activity of somatosensory inputs to the motor cortex). In HV, PAS and motor learning induced LTP-like plasticity of excitatory networks and a lasting decrease of LAI and LICI in the motor representation of the targeted or trained muscle. The better the motor performance, the larger was the decrease of LAI. Although motor performance in the patient group was similar to that of the control group, LAI did not decrease during the motor learning as it did in the control group. In contrast, LICI was normally modulated. In patients the results after PAS did not match those obtained after motor learning: LAI was paradoxically increased and LICI did not exhibit any change. In the normal situation, decreased excitability in inhibitory circuits after induction of LTP-like plasticity may help to shape the cortical maps according to the new sensorimotor task. In patients, the abnormal or absent modulation of afferent and intracortical long-interval inhibition might indicate maladaptive plasticity that possibly contributes to the difficulty that they have to learn a new sensorimotor task.“ PMID:22429246

A CSMP Commutation Model for Design Study of a Brushless DC Motor Power Conditioner for a Cruise Missile Fin Control Actuator.

DTIC Science & Technology

1985-06-01

STUDY OF A BRUSHLESS DC MOTOR POWER CONDITIONER FOR A CRUISE MISSILE FIN CONTROL ACTUATOR CA. by Peter Norman MacMillan June 1985 Thesis Advisor: A...TYPE OF REPORT & PERIOD COVERED A CSMP Commutation Model for Design Master’s Thesis Study of a Brushless DC Motor Power June, 1985 Conditioner for a...tactical missiles. A dynamic equivalent circuit model for the analysis of a small four pole brushless DC motor fed ty a transistorized power conditioner

Effects of voltage unbalance and system harmonics on the performance of doubly fed induction wind generators

NASA Astrophysics Data System (ADS)

Kiani, Morgan Mozhgan

Inherent difficulties in management of electric power in the presence of an increasing demand for more energy, non-conventional loads such as digital appliances, and non-sustainable imported fossil fuels has initiated a multi-folded effort by many countries to restructure the way electric energy is generated, dispatched, and consumed. Smart power grid is the manifestation of many technologies that would eventually transforms the existing power grid into a more flexible, fault resilient, and intelligent system. Integration of distributed renewable energy sources plays a central role in successful implementation of this transformation. Among the renewable options, wind energy harvesting offers superior engineering and economical incentives with minimal environmental impacts. Doubly fed induction generators (DFIG) have turned into a serious contender for wind energy generators due to their flexibility in control of active and reactive power with minimal silicon loss. Significant presence of voltage unbalance and system harmonics in finite inertia transmission lines can potentially undermine the reliability of these wind generators. The present dissertation has investigated the impacts of system unbalances and harmonics on the performance of the DFIG. Our investigation indicates that these effects can result in an undesirable undulation in the rotor shaft which can potentially invoke mechanical resonance, thereby causing catastrophic damages to the installations and the power grid. In order to remedy the above issue, a control solution for real time monitoring of the system unbalance and optimal excitation of the three phase rotor currents in a DFIG is offered. The optimal rotor currents will create appropriate components of the magneto-motive force in the airgap that will actively compensate the undesirable magnetic field originated by the stator windings. Due to the iterative nature of the optimization procedure, field reconstruction method has been incorporated

Aging assessment of large electric motors in nuclear power plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Villaran, M.; Subudhi, M.

1996-03-01

Large electric motors serve as the prime movers to drive high capacity pumps, fans, compressors, and generators in a variety of nuclear plant systems. This study examined the stressors that cause degradation and aging in large electric motors operating in various plant locations and environments. The operating history of these machines in nuclear plant service was studied by review and analysis of failure reports in the NPRDS and LER databases. This was supplemented by a review of motor designs, and their nuclear and balance of plant applications, in order to characterize the failure mechanisms that cause degradation, aging, and failuremore » in large electric motors. A generic failure modes and effects analysis for large squirrel cage induction motors was performed to identify the degradation and aging mechanisms affecting various components of these large motors, the failure modes that result, and their effects upon the function of the motor. The effects of large motor failures upon the systems in which they are operating, and on the plant as a whole, were analyzed from failure reports in the databases. The effectiveness of the industry`s large motor maintenance programs was assessed based upon the failure reports in the databases and reviews of plant maintenance procedures and programs.« less

A high-fat jelly diet restores bioenergetic balance and extends lifespan in the presence of motor dysfunction and lumbar spinal cord motor neuron loss in TDP-43A315T mutant C57BL6/J mice

PubMed Central

Coughlan, Karen S.; Halang, Luise; Woods, Ina

2016-01-01

ABSTRACT Transgenic transactivation response DNA-binding protein 43 (TDP-43) mice expressing the A315T mutation under control of the murine prion promoter progressively develop motor function deficits and are considered a new model for the study of amyotrophic lateral sclerosis (ALS); however, premature sudden death resulting from intestinal obstruction halts disease phenotype progression in 100% of C57BL6/J congenic TDP-43A315T mice. Similar to our recent results in SOD1G93A mice, TDP-43A315T mice fed a standard pellet diet showed increased 5′ adenosine monophosphate-activated protein kinase (AMPK) activation at postnatal day (P)80, indicating elevated energetic stress during disease progression. We therefore investigated the effects of a high-fat jelly diet on bioenergetic status and lifespan in TDP-43A315T mice. In contrast to standard pellet-fed mice, mice fed high-fat jelly showed no difference in AMPK activation up to P120 and decreased phosphorylation of acetly-CoA carboxylase (ACC) at early-stage time points. Exposure to a high-fat jelly diet prevented sudden death and extended survival, allowing development of a motor neuron disease phenotype with significantly decreased body weight from P80 onward that was characterised by deficits in Rotarod abilities and stride length measurements. Development of this phenotype was associated with a significant motor neuron loss as assessed by Nissl staining in the lumbar spinal cord. Our work suggests that a high-fat jelly diet improves the pre-clinical utility of the TDP-43A315T model by extending lifespan and allowing the motor neuron disease phenotype to progress, and indicates the potential benefit of this diet in TDP-43-associated ALS. PMID:27491077

A high-fat jelly diet restores bioenergetic balance and extends lifespan in the presence of motor dysfunction and lumbar spinal cord motor neuron loss in TDP-43A315T mutant C57BL6/J mice.

PubMed

Coughlan, Karen S; Halang, Luise; Woods, Ina; Prehn, Jochen H M

2016-09-01

Transgenic transactivation response DNA-binding protein 43 (TDP-43) mice expressing the A315T mutation under control of the murine prion promoter progressively develop motor function deficits and are considered a new model for the study of amyotrophic lateral sclerosis (ALS); however, premature sudden death resulting from intestinal obstruction halts disease phenotype progression in 100% of C57BL6/J congenic TDP-43(A315T) mice. Similar to our recent results in SOD1(G93A) mice, TDP-43(A315T) mice fed a standard pellet diet showed increased 5' adenosine monophosphate-activated protein kinase (AMPK) activation at postnatal day (P)80, indicating elevated energetic stress during disease progression. We therefore investigated the effects of a high-fat jelly diet on bioenergetic status and lifespan in TDP-43(A315T) mice. In contrast to standard pellet-fed mice, mice fed high-fat jelly showed no difference in AMPK activation up to P120 and decreased phosphorylation of acetly-CoA carboxylase (ACC) at early-stage time points. Exposure to a high-fat jelly diet prevented sudden death and extended survival, allowing development of a motor neuron disease phenotype with significantly decreased body weight from P80 onward that was characterised by deficits in Rotarod abilities and stride length measurements. Development of this phenotype was associated with a significant motor neuron loss as assessed by Nissl staining in the lumbar spinal cord. Our work suggests that a high-fat jelly diet improves the pre-clinical utility of the TDP-43(A315T) model by extending lifespan and allowing the motor neuron disease phenotype to progress, and indicates the potential benefit of this diet in TDP-43-associated ALS. © 2016. Published by The Company of Biologists Ltd.

The affective modulation of motor awareness in anosognosia for hemiplegia: Behavioural and lesion evidence

PubMed Central

Besharati, Sahba; Forkel, Stephanie J.; Kopelman, Michael; Solms, Mark; Jenkinson, Paul M.; Fotopoulou, Aikaterini

2014-01-01

The possible role of emotion in anosognosia for hemiplegia (i.e., denial of motor deficits contralateral to a brain lesion), has long been debated between psychodynamic and neurocognitive theories. However, there are only a handful of case studies focussing on this topic, and the precise role of emotion in anosognosia for hemiplegia requires empirical investigation. In the present study, we aimed to investigate how negative and positive emotions influence motor awareness in anosognosia. Positive and negative emotions were induced under carefully-controlled experimental conditions in right-hemisphere stroke patients with anosognosia for hemiplegia (n = 11) and controls with clinically normal awareness (n = 10). Only the negative, emotion induction condition resulted in a significant improvement of motor awareness in anosognosic patients compared to controls; the positive emotion induction did not. Using lesion overlay and voxel-based lesion-symptom mapping approaches, we also investigated the brain lesions associated with the diagnosis of anosognosia, as well as with performance on the experimental task. Anatomical areas that are commonly damaged in AHP included the right-hemisphere motor and sensory cortices, the inferior frontal cortex, and the insula. Additionally, the insula, putamen and anterior periventricular white matter were associated with less awareness change following the negative emotion induction. This study suggests that motor unawareness and the observed lack of negative emotions about one's disabilities cannot be adequately explained by either purely motivational or neurocognitive accounts. Instead, we propose an integrative account in which insular and striatal lesions result in weak interoceptive and motivational signals. These deficits lead to faulty inferences about the self, involving a difficulty to personalise new sensorimotor information, and an abnormal adherence to premorbid beliefs about the body. PMID:25481471

The affective modulation of motor awareness in anosognosia for hemiplegia: behavioural and lesion evidence.

PubMed

Besharati, Sahba; Forkel, Stephanie J; Kopelman, Michael; Solms, Mark; Jenkinson, Paul M; Fotopoulou, Aikaterini

2014-12-01

The possible role of emotion in anosognosia for hemiplegia (i.e., denial of motor deficits contralateral to a brain lesion), has long been debated between psychodynamic and neurocognitive theories. However, there are only a handful of case studies focussing on this topic, and the precise role of emotion in anosognosia for hemiplegia requires empirical investigation. In the present study, we aimed to investigate how negative and positive emotions influence motor awareness in anosognosia. Positive and negative emotions were induced under carefully-controlled experimental conditions in right-hemisphere stroke patients with anosognosia for hemiplegia (n = 11) and controls with clinically normal awareness (n = 10). Only the negative, emotion induction condition resulted in a significant improvement of motor awareness in anosognosic patients compared to controls; the positive emotion induction did not. Using lesion overlay and voxel-based lesion-symptom mapping approaches, we also investigated the brain lesions associated with the diagnosis of anosognosia, as well as with performance on the experimental task. Anatomical areas that are commonly damaged in AHP included the right-hemisphere motor and sensory cortices, the inferior frontal cortex, and the insula. Additionally, the insula, putamen and anterior periventricular white matter were associated with less awareness change following the negative emotion induction. This study suggests that motor unawareness and the observed lack of negative emotions about one's disabilities cannot be adequately explained by either purely motivational or neurocognitive accounts. Instead, we propose an integrative account in which insular and striatal lesions result in weak interoceptive and motivational signals. These deficits lead to faulty inferences about the self, involving a difficulty to personalise new sensorimotor information, and an abnormal adherence to premorbid beliefs about the body. Copyright © 2014 Elsevier Ltd. All

Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

DOEpatents

Coffey, H.T.

1993-10-19

A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle levitation. 3 figures.

Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

DOEpatents

Coffey, Howard T.

1993-01-01

A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.

The beneficial effects of berries on cognition, motor behavior, and neuronal function in aging

USDA-ARS?s Scientific Manuscript database

Previously, it has been shown that strawberry or blueberry supplementations, when fed to rats from 19-21 months of age, reverse age-related decrements in motor and cognitive performance. We have postulated that these effects may be the result of a number of positive benefits of the berry polyphenol...

Altitude Wind Tunnel Drive Motor Installation

NASA Image and Video Library

1943-07-21

Construction workers install the drive motor for the Altitude Wind Tunnel (AWT) in the Exhauster Building at the National Advisory Committee for Aeronautics (NACA) Aircraft Engine Research Laboratory. The AWT was capable of operating full-scale engines in air density, speed, and temperature similar to that found at high altitudes. The tunnel could produce wind speeds up to 500 miles per hour through a 20-foot-diameter test section at the standard operating altitude of 30,000 feet. The airflow was created by a large wooden fan near the tunnel’s southeast corner. This photograph shows the installation of the 18,000-horsepower drive motor inside the adjoining Exhauster Building in July 1943. The General Electric motor, whose support frame is seen in this photograph, connected to a drive shaft that extended from the building, through the tunnel shell, and into a 12-bladed, 31-foot-diameter spruce wood fan. Flexible couplings on the shaft allowed for the movement of the shell. The corner of the Exhauster Building was built around the motor after its installation. The General Electric induction motor could produce 10 to 410 revolutions per minute and create wind speeds up to 500 miles per hour, or Mach 0.63, at 30,000 feet. The AWT became operational in January 1944 and tested piston, turbojet and ramjet engines for nearly 20 years.

Aerobic exercise enhances neural correlates of motor skill learning.

PubMed

Singh, Amaya M; Neva, Jason L; Staines, W Richard

2016-03-15

Repetitive, in-phase bimanual motor training tasks can expand the excitable cortical area of the trained muscles. Recent evidence suggests that an acute bout of moderate-intensity aerobic exercise can enhance the induction of rapid motor plasticity at the motor hotspot. However, these changes have not been investigated throughout the entire cortical representation. Furthermore, it is unclear how exercise-induced changes in excitability may relate to motor performance. We investigated whether aerobic exercise could enhance the neural correlates of motor learning. We hypothesized that the combination of exercise and training would increase the excitable cortical area to a greater extent than either exercise or training alone, and that the addition of exercise would enhance performance on a motor training task. 25 young, healthy, right-handed individuals were recruited and divided into two groups and three experimental conditions. The exercise group performed exercise alone (EX) and exercise followed by training (EXTR) while the training group performed training alone (TR). The combination of exercise and training increased excitability within the cortical map of the trained muscle to a greater extent than training alone. However, there was no difference in performance between the two groups. These results indicate that exercise may enhance the cortical adaptations to motor skill learning. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of Solid State Inverters for AC Induction Motor Traction Propulsion Systems

DOT National Transportation Integrated Search

1980-12-01

This report is one of a series concerned with the application of ac machines as traction motors for railroad motive power. It presents results of a laboratory evaluation and computer analysis of different inverter systems. Three inverter systems, sin...

Ruminal Transcriptomic Analysis of Grass-Fed and Grain-Fed Angus Beef Cattle

PubMed Central

Li, Yaokun; Carrillo, José A.; Ding, Yi; He, YangHua; Zhao, Chunping; Zan, Linsen; Song, Jiuzhou

2015-01-01

Beef represents a major diet component and one of the major sources of protein in human. The beef industry in the United States is currently undergoing changes and is facing increased demands especially for natural grass-fed beef. The grass-fed beef obtained their nutrients directly from pastures, which contained limited assimilable energy but abundant amount of fiber. On the contrary, the grain-fed steers received a grain-based regime that served as an efficient source of high-digestible energy. Lately, ruminant animals have been accused to be a substantial contributor for the green house effect. Therefore, the concerns from environmentalism, animal welfare and public health have driven consumers to choose grass-fed beef. Rumen is one of the key workshops to digest forage constituting a critical step to supply enough nutrients for animals’ growth and production. We hypothesize that rumen may function differently in grass- and grain-fed regimes. The objective of this study was to find the differentially expressed genes in the ruminal wall of grass-fed and grain-fed steers, and then explore the potential biopathways. In this study, the RNA Sequencing (RNA-Seq) method was used to measure the gene expression level in the ruminal wall. The total number of reads per sample ranged from 24,697,373 to 36,714,704. The analysis detected 342 differentially expressed genes between ruminal wall samples of animals raised under different regimens. The Fisher’s exact test performed in the Ingenuity Pathway Analysis (IPA) software found 16 significant molecular networks. Additionally, 13 significantly enriched pathways were identified, most of which were related to cell development and biosynthesis. Our analysis demonstrated that most of the pathways enriched with the differentially expressed genes were related to cell development and biosynthesis. Our results provided valuable insights into the molecular mechanisms resulting in the phenotype difference between grass-fed and

Torque limit of PM motors for field-weakening region operation

DOEpatents

Royak, Semyon [Beachwood, OH; Harbaugh, Mark M [Richfield, OH

2012-02-14

The invention includes a motor controller and technique for controlling a permanent magnet motor. In accordance with one aspect of the present technique, a permanent magnet motor is controlled by receiving a torque command, determining a physical torque limit based on a stator frequency, determining a theoretical torque limit based on a maximum available voltage and motor inductance ratio, and limiting the torque command to the smaller of the physical torque limit and the theoretical torque limit. Receiving the torque command may include normalizing the torque command to obtain a normalized torque command, determining the physical torque limit may include determining a normalized physical torque limit, determining a theoretical torque limit may include determining a normalized theoretical torque limit, and limiting the torque command may include limiting the normalized torque command to the smaller of the normalized physical torque limit and the normalized theoretical torque limit.

Plasticity of cortical inhibition in dystonia is impaired after motor learning and paired-associative stimulation.

PubMed

Meunier, Sabine; Russmann, Heike; Shamim, Ejaz; Lamy, Jean-Charles; Hallett, Mark

2012-03-01

Artificial induction of plasticity by paired associative stimulation (PAS) in healthy volunteers (HV) demonstrates Hebbian-like plasticity in selected inhibitory networks as well as excitatory networks. In a group of 17 patients with focal hand dystonia and a group of 19 HV, we evaluated how PAS and the learning of a simple motor task influence the circuits supporting long-interval intracortical inhibition (LICI, reflecting activity of GABA(B) interneurons) and long-latency afferent inhibition (LAI, reflecting activity of somatosensory inputs to the motor cortex). In HV, PAS and motor learning induced long-term potentiation (LTP)-like plasticity of excitatory networks and a lasting decrease of LAI and LICI in the motor representation of the targeted or trained muscle. The better the motor performance, the larger was the decrease of LAI. Although motor performance in the patient group was similar to that of the control group, LAI did not decrease during the motor learning as it did in the control group. In contrast, LICI was normally modulated. In patients the results after PAS did not match those obtained after motor learning: LAI was paradoxically increased and LICI did not exhibit any change. In the normal situation, decreased excitability in inhibitory circuits after induction of LTP-like plasticity may help to shape the cortical maps according to the new sensorimotor task. In patients, the abnormal or absent modulation of afferent and intracortical long-interval inhibition might indicate maladaptive plasticity that possibly contributes to the difficulty that they have to learn a new sensorimotor task. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Altered impulse activity modifies synaptic physiology and mitochondria in crayfish phasic motor neurons.

PubMed

Nguyen, P V; Atwood, H L

1994-12-01

1. Crayfish phasic motor synapses produce large initial excitatory postsynaptic potentials (EPSPs) that fatigue rapidly during high-frequency stimulation. Periodic in vivo stimulation of an identified phasic abdominal extensor motor neuron (axon 3) induced long-term adaptation (LTA) of neuromuscular transmission: initial EPSP amplitude became smaller and synaptic depression was significantly reduced. We tested the hypothesis that activity-induced synaptic fatigue-resistance seen during LTA was dependent upon, or correlated with, mitochondrial oxidative competence. 2. Periodic unilateral conditioning stimulation of axon 3 entering each of two adjacent homologous abdominal segments (segments 2 and 3) increased the synaptic stamina in both "conditioned" axons; mean final EPSP amplitudes, recorded after 20 min of 5-Hz test stimulation, were significantly larger than those measured with the same protocol from contralateral unstimulated axons. 3. During 5-Hz test stimulation of the conditioned axon 3 of segment 3, acute superfusion with 0.8 mM dinitrophenol or 20 mM sodium azide [inhibitors of oxidative adenosinetriphosphate (ATP) synthesis] produced increased synaptic depression. Drug-free saline superfusion of the conditioned axon 3 of segment 2 in these same animals did not affect the increased synaptic fatigue resistance seen in this segment. Thus both successful induction (in axon 3 of saline-perfused segment 2) and attenuation (in axon 3 of drug-perfused segment 3) of the increased synaptic stamina can be demonstrated with this twin-segment conditioning protocol. 4. Confocal microscopic imaging of mitochondrial rhodamine-123 (Rh123) fluorescence was used to assess relative oxidative competence of conditioned and unconditioned phasic axons. Conditioned phasic axons showed significantly higher mean mitochondrial Rh123 fluorescence than contralateral unstimulated axons. In the same preparations that showed increased postconditioning Rh123 fluorescence, the synaptic

The sensory thalamus and cerebral motor cortex are affected concurrently during induction of anesthesia with propofol: a case series with intracranial electroencephalogram recordings.

PubMed

Verdonck, Olivier; Reed, Sean J; Hall, Jeffery; Gotman, Jean; Plourde, Gilles

2014-03-01

Brain imaging studies suggest that loss of consciousness induced by general anesthetics is associated with impairment of thalamic function. There is, however, limited information on the time course of these changes. We recently obtained intracranial electroencephalogram (EEG) recordings from the ventroposterolateral (VPL) nucleus of the thalamus and from the motor cortex during induction of anesthesia in three patients to study the time course of the alterations of cortical and thalamic function. The patients were American Society of Anesthesiologists physical status I-II males aged 33-57 yr with intractable central pain caused by brachial plexus injury (patient 1 and 2) or insular infarct (patient 3). Anesthesia was induced with propofol (2.5-3.1 mg·kg(-1) over 30-45 sec) followed, after loss of consciousness, by rocuronium for tracheal intubation. The data retained for analysis are from one minute before the start of propofol to 110 sec later during ventilation of the patients' lungs before tracheal intubation. Spectral analysis was used to measure absolute EEG power. Propofol caused significant increases of cortical and thalamic power in the delta to beta frequency bands (1-30 Hz). These increases of cortical and thalamic power occurred either concomitantly or within seconds of each other. Propofol also caused a decrease in cortical and thalamic high-gamma (62-200 Hz) power that also followed a similar time course. We conclude that induction of anesthesia with propofol in these patients was associated with concurrent alterations of cortical and sensory thalamic activity.

Chronic Exposure to Dietary Sterol Glucosides is Neurotoxic to Motor Neurons and Induces an ALS-PDC Phenotype

PubMed Central

Tabata, R. C.; Wilson, J. M. B.; Ly, P.; Zwiegers, P.; Kwok, D.; Van Kampen, J. M.; Cashman, N.; Shaw, C. A.

2008-01-01

Epidemiological studies of the Guamanian variants of amyotrophic lateral sclerosis (ALS) and parkinsonism, amyotrophic lateral sclerosis-parkinsonism dementia complex (ALS-PDC), have shown a positive correlation between consumption of washed cycad seed flour and disease occurrence. Previous in vivo studies by our group have shown that the same seed flour induces ALS and PDC phenotypes in out bred adult male mice. In vitro studies using isolated cycad compounds have also demonstrated that several of these are neurotoxic, specifically, a number of water insoluble phytosterol glucosides of which β-sitosterol β-d-glucoside (BSSG) forms the largest fraction. BSSG is neurotoxic to motor neurons and other neuronal populations in culture. The present study shows that an in vitro hybrid motor neuron (NSC-34) culture treated with BSSG undergoes a dose-dependent cell loss. Surviving cells show increased expression of HSP70, decreased cytosolic heavy neurofilament expression, and have various morphological abnormalities. CD-1 mice fed mouse chow pellets containing BSSG for 15 weeks showed motor deficits and motor neuron loss in the lumbar and thoracic spinal cord, along with decreased glutamate transporter labelling, and increased glial fibrillary acid protein reactivity. Other pathological outcomes included increased caspase-3 labelling in the striatum and decreased tyrosine-hydroxylase labelling in the striatum and substantia nigra. C57BL/6 mice fed BSSG-treated pellets for 10 weeks exhibited progressive loss of motor neurons in the lumbar spinal cord that continued to worsen even after the BSSG exposure ended. These results provide further support implicating sterol glucosides as one potential causal factor in the motor neuron pathology previously associated with cycad consumption and ALS-PDC. PMID:18196479

Changes in IL12A methylation pattern in livers from mice fed DDC.

PubMed

Oliva, J; French, S W

2012-04-01

Mallory-Denk body (MDB) formation is a component of alcoholic and non alcoholic hepatitis. Proteins of the TLR pathway were shown to be involved in the formation of MDBs, in mice fed DDC. TLR genes are upregulated and SAMe supplementation prevents this up regulation and prevented the formation of MDBs. DNA of livers from control mice, from mice fed DDC 10weeks, refed 1week with DDC and with DDC+SAMe were extracted and used to study the methylation pattern of genes involves in the TLR pathway. A PCR array was used to analyze it. Using PCR arrays for the mouse TLR pathway,24 genes were found whose expression of IL12A was regulated by the methylation of its gene. DDC fed for 10weeks reduced the methylation of the IL12A gene expression. This expression was also reduced when DDC was refed. However, when SAMe was fed, the intermediate level methylation of IL12A was up regulated to the intermediate level and the methylation of the promoter decreased compared to DDC refeeding or DDC 10weeks. IL12A is known to induce the production of IFNg by NK and L(T). We showed in a previous publication that IFNg is one of the major cytokines involved in the induction of MDB formation. The low expression of IL12A associated with the intermediate methylation of its promoter could explain one step in the mechanism which leads to the formation of MDBs. Copyright © 2012 Elsevier Inc. All rights reserved.

Modeling, analysis, control and design application guidelines of Doubly Fed Induction Generator (DFIG) for wind power applications

NASA Astrophysics Data System (ADS)

Masaud, Tarek

Double Fed Induction Generators (DFIG) has been widely used for the past two decades in large wind farms. However, there are many open-ended problems yet to be solved before they can be implemented in some specific applications. This dissertation deals with the general analysis, modeling, control and applications of the DFIG for large wind farm applications. A detailed "d-q" model of DFIG along with other applications is simulated using the MATLAB/Simulink platform. The simulation results have been discussed in detail in both sub-synchronous and super-synchronous mode of operation. An improved vector control strategy based on the rotor flux oriented vector control has been proposed to control the active power output of the DFIG. The new vector control strategy is compared with the stator flux oriented vector control which is commonly used. It is observed that the new improved vector control method provides a better active power tracking accuracy compare with the stator flux oriented vector control. The behavior of the DFIG -based wind farm under the various grid disturbances is also studied in this dissertation. The implementation of the Flexible AC Transmission System devices (FACTS) to overcome the voltage stability issue for such applications is investigated. The study includes the implementation of both a static synchronous compensator (STATCOM), and the static VAR compensator (SVC) as dynamic reactive power compensators at the point of common coupling to support DFIG-based wind farm during disturbances. Integrating FACTS protect the grid connected DFIG-based wind farm from going offline during and after the disturbances. It is found that the both devices improve the transient performance and therefore helps the wind turbine generator system to remain in service during grid faults. A comparison between the performance of the two devices in terms of the amount of reactive power injected, time response and the application cost has been discussed in this

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.

Oxidative Stress, Motor Abilities, and Behavioral Adjustment in Children Treated for Acute Lymphoblastic Leukemia.

PubMed

Hockenberry, Marilyn J; Krull, Kevin R; Insel, Kathleen C; Harris, Lynnette L; Gundy, Patricia M; Adkins, Kristin B; Pasvogel, Alice E; Taylor, Olga A; Koerner, Kari M; Montgomery, David W; Ross, Adam K; Hill, Adam; Moore, Ida M

2015-09-01

To examine associations among oxidative stress, fine and visual-motor abilities, and behavioral adjustment in children receiving chemotherapy for acute lymphoblastic leukemia (ALL)
. A prospective, repeated-measures design
. Two pediatric oncology settings in the southwestern United States. 89 children with ALL were followed from diagnosis to the end of chemotherapy. Serial cerebrospinal fluid samples were collected during scheduled lumbar punctures and analyzed for oxidative stress biomarkers. Children completed fine motor dexterity, visual processing speed, and visual-motor integration measures at three time points. Parents completed child behavior ratings at the same times. Oxidative stress, fine motor dexterity, visual processing, visual-motor integration, and behavioral adjustment
. Children with ALL had below-average fine motor dexterity, visual processing speed, and visual-motor integration following the induction phase of ALL therapy. By end of therapy, visual processing speed normalized, and fine motor dexterity and visual-motor integration remained below average. Oxidative stress measures correlated with fine motor dexterity and visual-motor integration. Decreased motor functioning was associated with increased hyperactivity and anxiety
. Oxidative stress occurs following chemo-therapy for childhood ALL and is related to impaired fine motor skills and visual symptoms
. Early intervention should be considered to prevent fine motor and visual-spatial deficits, as well as behavioral problems.

Quadro-pulse stimulation is more effective than paired-pulse stimulation for plasticity induction of the human motor cortex.

PubMed

Hamada, Masashi; Hanajima, Ritsuko; Terao, Yasuo; Arai, Noritoshi; Furubayashi, Toshiaki; Inomata-Terada, Satomi; Yugeta, Akihiro; Matsumoto, Hideyuki; Shirota, Yuichiro; Ugawa, Yoshikazu

2007-12-01

Repetitive paired-pulse transcranial magnetic stimulation (TMS) at I-wave periodicity has been shown to induce a motor-evoked potential (MEP) facilitation. We hypothesized that a greater enhancement of motor cortical excitability is provoked by increasing the number of pulses per train beyond those by paired-pulse stimulation (PPS). We explored motor cortical excitability changes induced by repetitive application of trains of four monophasic magnetic pulses (quadro-pulse stimulation: QPS) at 1.5-ms intervals, repeated every 5s over the motor cortex projecting to the hand muscles. The aftereffects of QPS were evaluated with MEPs to a single-pulse TMS, motor threshold (MT), and responses to brain-stem stimulation. These effects were compared to those after PPS. To evaluate the QPS safety, we also studied the spread of excitation and after discharge using surface electromyograms (EMGs) of hand and arm muscles. Sizes of MEPs from the hand muscle were enhanced for longer than 75min after QPS; they reverted to the baseline at 90min. Responses to brain-stem stimulation from the hand muscle and cortical MEPs from the forearm muscle were unchanged after QPS over the hand motor area. MT was unaffected by QPS. No spreads of excitation were detected after QPS. The appearance rate of after discharges during QPS was not different from that during sham stimulation. Results show that QPS can safely induce long-lasting, topographically specific enhancement of motor cortical excitability. QPS is more effective than PPS for inducing motor cortical plasticity.

Numerical analysis method for linear induction machines.

NASA Technical Reports Server (NTRS)

Elliott, D. G.

1972-01-01

A numerical analysis method has been developed for linear induction machines such as liquid metal MHD pumps and generators and linear motors. Arbitrary phase currents or voltages can be specified and the moving conductor can have arbitrary velocity and conductivity variations from point to point. The moving conductor is divided into a mesh and coefficients are calculated for the voltage induced at each mesh point by unit current at every other mesh point. Combining the coefficients with the mesh resistances yields a set of simultaneous equations which are solved for the unknown currents.

Utilizing fungus myceliated grain for molt induction and performance in commercial laying hens.

PubMed

Willis, W L; Isikhuemhen, O S; Allen, J W; Byers, A; King, K; Thomas, C

2009-10-01

Molting in poultry is used to rejuvenate hens for a second or third laying cycle. Feed withdrawal was once the most effective method used for molt induction; however, it has being phased out due to food safety and animal welfare concerns. This study evaluated the utilization of fungus myceliated grain as a safe and effective alternative for inducing molt, enhancing immunity, reducing Salmonella growth, and returning to egg production. Laying hens were subjected to 1 of 5 treatments: 1) nonfed (NF), 2) full-fed (FF), 3) fungus myceliated meal (FM), 4) 90% fungus myceliated meal+10% standard layer ration (FM-90), and 5) 90% alfalfa meal+10% fungus myceliated meal (AF-90). Each treatment condition was replicated 9 times during a 9-d molt period. The results revealed that egg production for treatments 1 and 3 ceased completely by d 5, whereas hens in treatments 4 and 5 ceased egg production by d 6. The percentage of BW loss decreased significantly (P<0.05) in treatments 1 (57%), 2 (8%), 3 (35%), 4 (37%), and 5 (44%). Ovary weights of hens fed all molting diets decreased significantly from the full-fed control but did not differ significantly (P<0.05) from each other. Salmonella population in the crop, ovary, and ceca from hens differed significantly (P<0.05) among treatments. Return to egg production differed between treatments with higher production beginning in treatment 3 and ending in treatment 5. Antibody titers did differ (P<0.05) among treatments. From these results, fungus myceliated meal appears to be a viable alternative to conventional feed withdrawal and other methods for the successful induction of molt and retention of postmolt performance.

The increase in the starting torque of PMSM motor by applying of FOC method

NASA Astrophysics Data System (ADS)

Plachta, Kamil

2017-05-01

The article presents field oriented control method of synchronous permanent magnet motor equipped in optical sensors. This method allows for a wide range regulation of torque and rotational speed of the electric motor. The paper presents mathematical model of electric motor and vector control method. Optical sensors have shorter time response as compared to the inductive sensors, which allow for faster response of the electronic control system to changes of motor loads. The motor driver is based on the digital signal processor which performs advanced mathematical operations in real time. The appliance of Clark and Park transformation in the software defines the angle of rotor position. The presented solution provides smooth adjustment of the rotational speed in the first operating zone and reduces the dead zone of the torque in the second and third operating zones.

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.

Field-circuit analysis and measurements of a single-phase self-excited induction generator

NASA Astrophysics Data System (ADS)

Makowski, Krzysztof; Leicht, Aleksander

2017-12-01

The paper deals with a single-phase induction machine operating as a stand-alone self-excited single-phase induction generator for generation of electrical energy from renewable energy sources. By changing number of turns and size of wires in the auxiliary stator winding, an improvement of performance characteristics of the generator were obtained as regards no-load and load voltage of the stator windings as well as stator winding currents of the generator. Field-circuit simulation models of the generator were developed using Flux2D software package for the generator with shunt capacitor in the main stator winding. The obtained results have been validated experimentally at the laboratory setup using the single-phase capacitor induction motor of 1.1 kW rated power and 230 V voltage as a base model of the generator.

Stimulus uncertainty enhances long-term potentiation-like plasticity in human motor cortex.

PubMed

Sale, Martin V; Nydam, Abbey S; Mattingley, Jason B

2017-03-01

Plasticity can be induced in human cortex using paired associative stimulation (PAS), which repeatedly and predictably pairs a peripheral electrical stimulus with transcranial magnetic stimulation (TMS) to the contralateral motor region. Many studies have reported small or inconsistent effects of PAS. Given that uncertain stimuli can promote learning, the predictable nature of the stimulation in conventional PAS paradigms might serve to attenuate plasticity induction. Here, we introduced stimulus uncertainty into the PAS paradigm to investigate if it can boost plasticity induction. Across two experimental sessions, participants (n = 28) received a modified PAS paradigm consisting of a random combination of 90 paired stimuli and 90 unpaired (TMS-only) stimuli. Prior to each of these stimuli, participants also received an auditory cue which either reliably predicted whether the upcoming stimulus was paired or unpaired (no uncertainty condition) or did not predict the upcoming stimulus (maximum uncertainty condition). Motor evoked potentials (MEPs) evoked from abductor pollicis brevis (APB) muscle quantified cortical excitability before and after PAS. MEP amplitude increased significantly 15 min following PAS in the maximum uncertainty condition. There was no reliable change in MEP amplitude in the no uncertainty condition, nor between post-PAS MEP amplitudes across the two conditions. These results suggest that stimulus uncertainty may provide a novel means to enhance plasticity induction with the PAS paradigm in human motor cortex. To provide further support to the notion that stimulus uncertainty and prediction error promote plasticity, future studies should further explore the time course of these changes, and investigate what aspects of stimulus uncertainty are critical in boosting plasticity. Copyright © 2016 Elsevier Ltd. All rights reserved.

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. Copyright © 2012 Elsevier B.V. All rights reserved.

Permanent magnets for vehicle-propulsion motors: Cost/availability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oman, H.; Simpson-Clark, R.

1996-12-31

Alternating-current induction motors have been used for fuel-pumping and air-conditioning in airplanes. Series and shunt dc motors have propelled vehicles. The power received by motors goes into producing output torque and magnetic fields. Today these fields can be produced with rare-earth permanent magnets which do not consume input power. Dramatic improvements in motor efficiency can result. Furthermore, with efficient variable-speed controllers using MOSFET and IGBT semiconductors, electric motors can replace the hydraulic actuators that move aircraft surfaces and retract landing gear. The 1993 cost for the magnets in a 100 kW motor was $1,500. Improved production processes are expected tomore » drop this cost to around $400. However, today`s rare-earth magnet-materials are by-products of mines that produce other metals and minerals. The authors explore the effect on cost of increased demand for the pertinent rare-earth elements, neodymium, cobalt, and samarium. A higher price will cause more elements to be extracted from existing mines. The opening of new rare-earth-element mines is another possibility. In 1993 the $250-per-kg cost for neodymium-iron-boron magnets included $190 for processing. Processing cost can drop to $30 per kg of magnet when production reaches 60 tons per month. The cost of the raw material for the magnets will be affected by man factors in a complex scenario.« less

Wind-energy recovery by a static Scherbius induction generator

NASA Astrophysics Data System (ADS)

Smith, G. A.; Nigim, K. A.

1981-11-01

The paper describes a technique for controlling a doubly fed induction generator driven by a windmill, or other form of variable-speed prime mover, to provide power generation into the national grid system. The secondary circuit of the generator is supplied at a variable frequency from a current source inverter which for test purposes is rated to allow energy recovery, from a simulated windmill, from maximum speed to standstill. To overcome the stability problems normally associated with doubly fed machines a novel signal generator, which is locked in phase with the rotor EMF, controls the secondary power to provide operation over a wide range of subsynchronous and supersynchronous speeds. Consideration of power flow enables the VA rating of the secondary power source to be determined as a function of the gear ratio and online operating range of the system. A simple current source model is used to predict performance which is compared with experimental results. The results indicate a viable system, and suggestions for further work are proposed.

[Fast determination of induction period of motor gasoline using Fourier transform attenuated total reflection infrared spectroscopy].

PubMed

Liu, Ya-Fei; Yuan, Hong-Fu; Song, Chun-Feng; Xie, Jin-Chun; Li, Xiao-Yu; Yan, De-Lin

2014-11-01

A new method is proposed for the fast determination of the induction period of gasoline using Fourier transform attenuated total reflection infrared spectroscopy (ATR-FTIR). A dedicated analysis system with the function of spectral measurement, data processing, display and storage was designed and integrated using a Fourier transform infrared spectrometer module and chemometric software. The sample presentation accessory designed which has advantages of constant optical path, convenient sample injection and cleaning is composed of a nine times reflection attenuated total reflectance (ATR) crystal of zinc selenide (ZnSe) coated with a diamond film and a stainless steel lid with sealing device. The influence of spectral scanning number and repeated sample loading times on the spectral signal-to-noise ratio was studied. The optimum spectral scanning number is 15 times and the optimum sample loading number is 4 times. Sixty four different gasoline samples were collected from the Beijing-Tianjin area and the induction period values were determined as reference data by standard method GB/T 8018-87. The infrared spectra of these samples were collected in the operating condition mentioned above using the dedicated fast analysis system. Spectra were pretreated using mean centering and 1st derivative to reduce the influence of spectral noise and baseline shift A PLS calibration model for the induction period was established by correlating the known induction period values of the samples with their spectra. The correlation coefficient (R2), standard error of calibration (SEC) and standard error of prediction (SEP) of the model are 0.897, 68.3 and 91.9 minutes, respectively. The relative deviation of the model for gasoline induction period prediction is less than 5%, which meets the requirements of repeatability tolerance in GB method. The new method is simple and fast. It takes no more than 3 minutes to detect one sample. Therefore, the method is feasible for implementing

Motor Drive Technologies for the Power-by-Wire (PBW) Program: Options, Trends and Tradeoffs

NASA Technical Reports Server (NTRS)

Elbuluk, Malik E.; Kankam, M. David

1995-01-01

Power-By-Wire (PBW) is a program involving the replacement of hydraulic and pneumatic systems currently used in aircraft with an all-electric secondary power system. One of the largest loads of the all-electric secondary power system will be the motor loads which include pumps, compressors and Electrical Actuators (EA's). Issues of improved reliability, reduced maintenance and efficiency, among other advantages, are the motivation for replacing the existing aircraft actuators with electrical actuators. An EA system contains four major components. These are the motor, the power electronic converters, the actuator and the control system, including the sensors. This paper is a comparative literature review in motor drive technologies, with a focus on the trends and tradeoffs involved in the selection of a particular motor drive technology. The reported research comprises three motor drive technologies. These are the induction motor (IM), the brushless dc motor (BLDCM) and the switched reluctance motor (SRM). Each of the three drives has the potential for application in the PBW program. Many issues remain to be investigated and compared between the three motor drives, using actual mechanical loads expected in the PBW program.

Investigation of Combined Motor/Magnetic Bearings for Flywheel Energy Storage Systems

NASA Technical Reports Server (NTRS)

Hofmann, Heath

2003-01-01

Dr. Hofmann's work in the summer of 2003 consisted of two separate projects. In the first part of the summer, Dr. Hofmann prepared and collected information regarding rotor losses in synchronous machines; in particular, machines with low rotor losses operating in vacuum and supported by magnetic bearings, such as the motor/generator for flywheel energy storage systems. This work culminated in a presentation at NASA Glenn Research Center on this topic. In the second part, Dr. Hofmann investigated an approach to flywheel energy storage where the phases of the flywheel motor/generator are connected in parallel with the phases of an induction machine driving a mechanical actuator. With this approach, additional power electronics for driving the flywheel unit are not required. Simulations of the connection of a flywheel energy storage system to a model of an electromechanical actuator testbed at NASA Glenn were performed that validated the proposed approach. A proof-of-concept experiment using the D1 flywheel unit at NASA Glenn and a Sundstrand induction machine connected to a dynamometer was successfully conducted.

Comparison of Magnetic Characteristics of Powder Magnetic Core and Evaluation of Motor Characteristics

NASA Astrophysics Data System (ADS)

Enomoto, Yuji; Ito, Motoya; Masaki, Ryozo; Yamazaki, Katsuyuki; Asaka, Kazuo; Ishihara, Chio; Ohiwa, Syoji

A magnetic characteristic measurement, a motor characteristic forecast, and an experimental evaluation of various powder magnetic cores were performed aiming at a fixed quantity grasp when the powder magnetic core was applied to the motor core as the magnetic material. The manufacturing conditions were changed, and magnetic characteristic compares a direct current magnetization characteristic and an iron disadvantageous characteristic with the silicon steel board for a different powder magnetic core. Therefore, though some permeabilities are low, characteristics almost equal to those of a silicon steel board were obtained in the maximum saturation magnetic induction, which confirms that the powder magnetic core in disadvantageous iron in a certain frequency domain, and to confirm disadvantageous iron lowers. Moreover, it has been shown to obtain characteristics almost equal to the silicon steel board when compared in terms of motor efficiency, though some disadvantageous iron increases since the effect when applying to the motor is verified the silicon steel board and the comparison evaluation for the surface type permanent magnet motor.

Wireless Monitoring of Induction Machine Rotor Physical Variables

PubMed Central

Doolan Fernandes, Jefferson; Carvalho Souza, Francisco Elvis; de Paiva, José Alvaro

2017-01-01

With the widespread use of electric machines, there is a growing need to extract information from the machines to improve their control systems and maintenance management. The present work shows the development of an embedded system to perform the monitoring of the rotor physical variables of a squirrel cage induction motor. The system is comprised of: a circuit to acquire desirable rotor variable(s) and value(s) that send it to the computer; a rectifier and power storage circuit that converts an alternating current in a continuous current but also stores energy for a certain amount of time to wait for the motor’s shutdown; and a magnetic generator that harvests energy from the rotating field to power the circuits mentioned above. The embedded system is set on the rotor of a 5 HP squirrel cage induction motor, making it difficult to power the system because it is rotating. This problem can be solved with the construction of a magnetic generator device to avoid the need of using batteries or collector rings and will send data to the computer using a wireless NRF24L01 module. For the proposed system, initial validation tests were made using a temperature sensor (DS18b20), as this variable is known as the most important when identifying the need for maintenance and control systems. Few tests have shown promising results that, with further improvements, can prove the feasibility of using sensors in the rotor. PMID:29156564

Efficacy and immunogenicity of live-attenuated human rotavirus vaccine in breast-fed and formula-fed European infants.

PubMed

Vesikari, Timo; Prymula, Roman; Schuster, Volker; Tejedor, Juan-C; Cohen, Robert; Bouckenooghe, Alain; Damaso, Silvia; Han, Htay Htay

2012-05-01

Rotavirus is the main cause of severe gastroenteritis and diarrhea in infants and young children less than 5 years of age. Potential impact of breast-feeding on the efficacy and immunogenicity of human rotavirus G1P[8] vaccine was examined in this exploratory analysis. Healthy infants (N = 3994) aged 6-14 weeks who received 2 doses of human rotavirus vaccine/placebo according to a 0-1 or 0-2 month schedule were followed for rotavirus gastroenteritis during 2 epidemic seasons. Rotavirus IgA seroconversion rate (anti-IgA antibody concentration ≥ 20 mIU/mL) and geometric mean concentrations were measured prevaccination and 1-2 months post-dose 2. Vaccine efficacy against any and severe rotavirus gastroenteritis was analyzed according to the infants being breast-fed or exclusively formula-fed at the time of vaccination. Antirotavirus IgA seroconversion rate was 85.5% (95% confidence interval [CI]: 82.4-88.3) in breast-fed and 89.2% (95% CI: 84.2-93) in exclusively formula-fed infants; geometric mean concentrations in the respective groups were 185.8 U/mL (95% CI: 161.4-213.9) and 231.5 U/mL (95% CI: 185.9-288.2). Vaccine efficacy was equally high in breast-fed and exclusively formula-fed children in the first season but fell in breast-fed infants in the second rotavirus season. During the combined 2-year efficacy follow-up period, vaccine efficacy against any rotavirus gastroenteritis was 76.2% (95% CI: 68.7-82.1) and 89.8% (95% CI: 77.6-95.9) and against severe rotavirus gastroenteritis 88.4% (95% CI: 81.6-93) and 98.1% (95% CI: 88.2-100) in the breast-fed and exclusively formula-fed infants, respectively. The difference in immunogenicity of human rotavirus vaccine in breast-fed and exclusively formula-fed infants was small. Vaccine efficacy was equally high in breast-fed and exclusively formula-fed children in the first season. Breast-feeding seemed to reduce slightly the efficacy in the second season.

Improved motors for utility applications: Volume 6, Squirrel-cage rotor analysis: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Griffith, J.W.; McCoy, R.M.

1986-11-01

An analysis of squirrel cage induction motor rotors was undertaken in response to an Industry Assessment Study finding 10% of motor failures to be rotor related. The analysis focuses on evaluating rotor design life. The evaluation combines state-of-the-art electromagnetic, thermal, and structural solution techniques into an integrated analysis and presents a simple summary. Finite element techniques are central tools in the analysis. The analysis is applied to a specific forced draft fan drive design. Fans as a category of application have a higher failure rate than other categories of power station auxiliary motor applications. Forced-draft fan drives are one ofmore » the major fan drives which accelerate a relatively high value of rotor load inertia. Various starting and operating conditions are studied for this forced-draft fan drive motor including a representative application duty cycle.« less

Calculation of cogging force in a novel slotted linear tubular brushless permanent magnet motor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Z.Q.; Hor, P.J.; Howe, D.

1997-09-01

There is an increasing requirement for controlled linear motion over short and long strokes, in the factory automation and packaging industries, for example. Linear brushless PM motors could offer significant advantages over conventional actuation technologies, such as motor driven cams and linkages and pneumatic rams--in terms of efficiency, operating bandwidth, speed and thrust control, stroke and positional accuracy, and indeed over other linear motor technologies, such as induction motors. Here, a finite element/analytical based technique for the prediction of cogging force in a novel topology of slotted linear brushless permanent magnet motor has been developed and validated. The various forcemore » components, which influence cogging are pre-calculated by the finite element analysis of some basic magnetic structures, facilitate the analytical synthesis of the resultant cogging force. The technique can be used to aid design for the minimization of cogging.« less

7-Fluoro-1,3-diphenylisoquinoline reverses motor and non-motor symptoms induced by MPTP in mice: Role of striatal neuroinflammation.

PubMed

Sampaio, Tuane Bazanella; Marcondes Sari, Marcel Henrique; Pesarico, Ana Paula; Mantovani, Anderson Carboni; Zeni, Gilson; Nogueira, Cristina Wayne

2018-01-15

Parkinson's disease (PD) is a dopaminergic neurodegenerative disorder, which presents motor and non-motor symptoms. 7-Fluoro-1,3-diphenylisoquinoline (FDPI) is an isoquinoline compound with antioxidant and antidepressant properties. This study investigated whether FDPI reverses motor and non-motor symptoms in an acute mouse model of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). It was also assessed the anti-inflammatory mechanisms in FDPI pharmacological action. C57Bl/6 male adult mice received four MPTP (20mg/kg, intraperitoneal) or saline (vehicle) injections to induce an acute PD model. FDPI (10mg/kg, intragastric) was daily administered to mice from the 2nd to 9th day after the induction and mice performed the behavioral tests on the 8th and 9th days. Striatum samples were collected for biochemical and molecular analyses. The results of the rotarod and challenging beam tests demonstrated that the administration of FDPI attenuated the impairments in balance and coordination of mice induced by MPTP. The FDPI reversed the short-term memory deficit and depressive-like behavior induced by MPTP in mice. FDPI attenuated the reduction in the striatal tyrosine hydroxylase levels, and it reversed the increase in the cyclooxygenase-2 levels and myeloperoxidase activity caused by MPTP in mice. Therefore, FDPI reversed motor and non-motor symptoms induced by an acute PD model and its restorative effects seem to be mediated by an anti-inflammatory action associated with a modulation of the striatal cyclooxygenase-2 levels and myeloperoxidase activity. Copyright © 2017 Elsevier B.V. All rights reserved.

Induction of parkinsonism-related proteins in the spinal motor neurons of transgenic mouse carrying a mutant SOD1 gene.

PubMed

Morimoto, Nobutoshi; Nagai, Makiko; Miyazaki, Kazunori; Ohta, Yasuyuki; Kurata, Tomoko; Takehisa, Yasushi; Ikeda, Yoshio; Matsuura, Tohru; Asanuma, Masato; Abe, Koji

2010-06-01

Amyotrophic lateral sclerosis is a progressive and fatal disease caused by selective death of motor neurons, and a number of these patients carry mutations in the superoxide dismutase 1 (SOD1) gene involved in ameliorating oxidative stress. Recent studies indicate that oxidative stress and disruption of mitochondrial homeostasis is a common mechanism for motor neuron degeneration in amyotrophic lateral sclerosis and the loss of midbrain dopamine neurons in Parkinson's disease. Therefore, the present study investigated the presence and alterations of familial Parkinson's disease-related proteins, PINK1 and DJ-1, in spinal motor neurons of G93ASOD1 transgenic mouse model of amyotrophic lateral sclerosis. Following onset of disease, PINK1 and DJ-1 protein expression increased in the spinal motor neurons. The activated form of p53 also increased and translocated to the nuclei of spinal motor neurons, followed by increased expression of p53-activated gene 608 (PAG608). This is the first report demonstrating that increased expression of PAG608 correlates with activation of phosphorylated p53 in spinal motor neurons of an amyotrophic lateral sclerosis model. These results provide further evidence of the profound correlations between spinal motor neurons of amyotrophic lateral sclerosis and parkinsonism-related proteins.

10 CFR Appendix A to Subpart B of... - Policy Statement for Electric Motors Covered Under the Energy Policy and Conservation Act

Code of Federal Regulations, 2011 CFR

2011-01-01

... with NEMA Design A or B characteristics, or equivalent designs such as IEC Design N (IEC); and (8... design for use at variable speeds. However, NEMA Design A or B motors that are single speed, meet all... single-speed induction motor, built in a two-digit frame number series in accordance with NEMA Standards...

10 CFR Appendix A to Subpart B of... - Policy Statement for Electric Motors Covered Under the Energy Policy and Conservation Act

Code of Federal Regulations, 2012 CFR

2012-01-01

... with NEMA Design A or B characteristics, or equivalent designs such as IEC Design N (IEC); and (8... design for use at variable speeds. However, NEMA Design A or B motors that are single speed, meet all... single-speed induction motor, built in a two-digit frame number series in accordance with NEMA Standards...

Estimated Exposure to Arsenic in Breastfed and Formula-Fed Infants in a United States Cohort

PubMed Central

Carignan, Courtney C.; Jackson, Brian P.; Farzan, Shohreh F.; Gandolfi, A. Jay; Punshon, Tracy; Folt, Carol L.; Karagas, Margaret R.

2015-01-01

Background: Previous studies indicate that concentrations of arsenic in breast milk are relatively low even in areas with high drinking-water arsenic. However, it is uncertain whether breastfeeding leads to reduced infant exposure to arsenic in regions with lower arsenic concentrations. Objective: We estimated the relative contributions of breast milk and formula to arsenic exposure during early infancy in a U.S. population. Methods: We measured arsenic in home tap water (n = 874), urine from 6-week-old infants (n = 72), and breast milk from mothers (n = 9) enrolled in the New Hampshire Birth Cohort Study (NHBCS) using inductively coupled plasma mass spectrometry. Using data from a 3-day food diary, we compared urinary arsenic across infant feeding types and developed predictive exposure models to estimate daily arsenic intake from breast milk and formula. Results: Urinary arsenic concentrations were generally low (median, 0.17 μg/L; maximum, 2.9 μg/L) but 7.5 times higher for infants fed exclusively with formula than for infants fed exclusively with breast milk (β = 2.02; 95% CI: 1.21, 2.83; p < 0.0001, adjusted for specific gravity). Similarly, the median estimated daily arsenic intake by NHBCS infants was 5.5 times higher for formula-fed infants (0.22 μg/kg/day) than for breastfed infants (0.04 μg/kg/day). Given median arsenic concentrations measured in NHBCS tap water and previously published for formula powder, formula powder was estimated to account for ~ 70% of median exposure among formula-fed NHBCS infants. Conclusions: Our findings suggest that breastfed infants have lower arsenic exposure than formula-fed infants, and that both formula powder and drinking water can be sources of exposure for U.S. infants. Citation: Carignan CC, Cottingham KL, Jackson BP, Farzan SF, Gandolfi AJ, Punshon T, Folt CL, Karagas MR. 2015. Estimated exposure to arsenic in breastfed and formula-fed infants in a United States cohort. Environ Health Perspect 123:500–506;�

Analysis of ZDDP Content and Thermal Decomposition in Motor Oils Using NAA and NMR

NASA Astrophysics Data System (ADS)

Ferguson, S.; Johnson, J.; Gonzales, D.; Hobbs, C.; Allen, C.; Williams, S.

Zinc dialkyldithiophosphates (ZDDPs) are one of the most common anti-wear additives present in commercially-available motor oils. The ZDDP concentrations of motor oils are most commonly determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES). As part of an undergraduate research project, we have determined the Zn concentrations of eight commercially-available motor oils and one oil additive using neutron activation analysis (NAA), which has potential for greater accuracy and less sensitivity to matrix effects as compared to ICP-AES. The 31P nuclear magnetic resonance (31P-NMR) spectra were also obtained for several oil additive samples which have been heated to various temperatures in order to study the thermal decomposition of ZDDPs.

Growth and development of premature infants fed predominantly human milk, predominantly premature infant formula, or a combination of human milk and premature formula.

PubMed

O'Connor, Deborah L; Jacobs, Joan; Hall, Robert; Adamkin, David; Auestad, Nancy; Castillo, Marcella; Connor, William E; Connor, Sonja L; Fitzgerald, Kathleen; Groh-Wargo, Sharon; Hartmann, E Eugenie; Janowsky, Jeri; Lucas, Alan; Margeson, Dean; Mena, Patricia; Neuringer, Martha; Ross, Gail; Singer, Lynn; Stephenson, Terence; Szabo, Joanne; Zemon, Vance

2003-10-01

In a recent meta-analysis, human milk feeding of low birth-weight (LBW) infants was associated with a 5.2 point improvement in IQ tests. However, in the studies in this meta-analysis, feeding regimens were used (unfortified human milk, term formula) that no longer represent recommended practice. To compare the growth, in-hospital feeding tolerance, morbidity, and development (cognitive, motor, visual, and language) of LBW infants fed different amounts of human milk until term chronologic age (CA) with those of LBW infants fed nutrient-enriched formulas from first enteral feeding. The data in this study were collected in a previous randomized controlled trial assessing the benefit of supplementing nutrient-enriched formulas for LBW infants with arachidonic acid and docosahexaenoic acid. Infants (n = 463, birth weight, 750-1,800 g) were enrolled from nurseries located in Chile, the United Kingdom, and the United States. If human milk was fed before hospital discharge, it was fortified (3,050-3,300 kJ/L, 22-24 kcal/oz). As infants were weaned from human milk, they were fed nutrient-enriched formula with or without arachidonic and docosahexaenoic acids (3,300 kJ/L before term, 3,050 kJ/L thereafter) until 12 months CA. Formula fed infants were given nutrient-enriched formula with or without added arachidonic and docosahexaenoic acids (3,300 kJ/L to term, 3,050 kJ/L thereafter) until 12 months CA. For the purposes of this evaluation, infants were categorized into four mutually exclusive feeding groups: 1) predominantly human milk fed until term CA (PHM-T, n = 43); 2) >/= 50% energy from human milk before hospital discharge (>/= 50% HM, n = 98); 3) < 50% of energy from human milk before hospital discharge (< 50% HM, n = 203); or 4) predominantly formula fed until term CA (PFF-T, n = 119). PFF-T infants weighed approximately 500 g more at term CA than did PHM-T infants. This absolute difference persisted until 6 months CA. PFF-T infants were also longer (1.0-1.5 cm) and

Depletion of suppressor T cells by 2'-deoxyguanosine abrogates tolerance in mice fed ovalbumin and permits the induction of intestinal delayed-type hypersensitivity.

PubMed Central

Mowat, A M

1986-01-01

We have re-examined the role of suppressor T cells (Ts) in regulating immune responses to fed proteins by investigating the effect of 2'-deoxyguanosine (dGuo) on systemic and intestinal immunity in mice fed ovalbumin (OVA). Administration of dGuo for 10 days abrogated the suppression of systemic delayed-type hypersensitivity (DTH) and antibody responses normally found after feeding OVA, and also prevented the generation of OVA-specific Ts. In parallel, mice given dGuo and fed OVA developed sensitization to OVA in the gut-associated lymphoid tissues (GALT) after oral challenge with OVA and had increased intraepithelial lymphocyte (IEL) counts and crypt cell production rates (CCPR) in the jejunal mucosa, indicating the presence of a local DTH response. These findings confirm the importance of Ts in preventing hypersensitivity to dietary protein antigens and suggest that enteropathies associated with food hypersensitivity are due to a defect in Ts activity. PMID:2940171

Early Cognitive/Social Deficits and Late Motor Phenotype in Conditional Wild-Type TDP-43 Transgenic Mice.

PubMed

Alfieri, Julio A; Silva, Pablo R; Igaz, Lionel M

2016-01-01

Frontotemporal Dementia (FTD) and amyotrophic lateral sclerosis (ALS) are two neurodegenerative diseases associated to mislocalization and aggregation of TAR DNA-binding protein 43 (TDP-43). To investigate in depth the behavioral phenotype associated with this proteinopathy, we used as a model transgenic (Tg) mice conditionally overexpressing human wild-type TDP 43 protein (hTDP-43-WT) in forebrain neurons. We previously characterized these mice at the neuropathological level and found progressive neurodegeneration and other features that evoke human TDP-43 proteinopathies of the FTD/ALS spectrum. In the present study we analyzed the behavior of mice at multiple domains, including motor, social and cognitive performance. Our results indicate that young hTDP-43-WT Tg mice (1 month after post-weaning transgene induction) present a normal motor phenotype compared to control littermates, as assessed by accelerated rotarod performance, spontaneous locomotor activity in the open field test and a mild degree of spasticity shown by a clasping phenotype. Analysis of social and cognitive behavior showed a rapid installment of deficits in social interaction, working memory (Y-maze test) and recognition memory (novel object recognition test) in the absence of overt motor abnormalities. To investigate if the motor phenotype worsen with age, we analyzed the behavior of mice after long-term (up to 12 months) transgene induction. Our results reveal a decreased performance on the rotarod test and in the hanging wire test, indicating a motor phenotype that was absent in younger mice. In addition, long-term hTDP-43-WT expression led to hyperlocomotion in the open field test. In sum, these results demonstrate a time-dependent emergence of a motor phenotype in older hTDP-43-WT Tg mice, recapitulating aspects of clinical FTD presentations with motor involvement in human patients, and providing a complementary animal model for studying TDP-43 proteinopathies.

Power-Factor and Torque Calculation under Consideration of Cross Saturation of the Interior Permanent Magnet Synchronous Motor with Brushless Field Excitation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Seong T; Burress, Timothy A; Tolbert, Leon M

2009-01-01

This paper introduces a new method for calculating the power factor and output torque by considering the cross saturation between direct-axis (d-axis) and quadrature-axis (q-axis) of an interior permanent magnet synchronous motor (IPMSM). The conventional two-axis IPMSM model is modified to include the cross saturation effect by adding the cross-coupled inductance terms. This paper also contains the new method of calculating the cross-coupled inductance values as well as self-inductance values in d- and q-axes. The analyzed motor is a high-speed brushless field excitation machine that offers high torque per ampere per core length at low speed and weakened flux atmore » high speed, which was developed for the traction motor of a hybrid electric vehicle. The conventional two-axis IPMSM model was modified to include the cross-saturation effect by adding the cross-coupled inductance terms Ldq and Lqd. By the advantage of the excited structure of the experimental IPMSM, the analyzing works were performed under two conditions, the highest and lowest excited conditions. Therefore, it is possible to investigate the cross-saturation effect when a machine has higher magnetic flux from its rotor. The following is a summary of conclusions that may be drawn from this work: (1) Considering cross saturation of an IPMSM offers more accurate expected values of motor parameters in output torque calculation, especially when negative d-axis current is high; (2) A less saturated synchronous machine could be more affected by the cross-coupled saturation effect; (3) Both cross-coupled inductances, L{sub qd} and L{sub dq}, are mainly governed by d-axis current rather than q-axis current; (4) The modified torque equation, can be used for the dynamic model of an IPMSM for developing a better control model or control strategy; and (5) It is possible that the brushless field excitation structure has a common magnetic flux path on both d- and q-axis, and as a result, the reluctance torque of

[Long-chain polyunsaturated fatty acids in breast-fed and formula fed healthy infants].

PubMed

Decsi, T; Adamovich, K; Szász, M; Berthold, K

1995-03-26

While human milk contains considerable amounts of long-chain polyunsaturated fatty acids (LCP), most formulae contain only the precursors of LCP synthesis (linoleic and alpha-linolenic acids) but are devoid of preformed dietary LCP such as are arachidonic and docosahexaenoic acids. LCP contents in plasma phospholipids (PL), triglycerides (TG) and sterol esters (STE) were measured by high resolution capillary gas-liquid chromatography in healthy, term infants fed human milk of formula. Percentage contributions of the precursor fatty acids were similar or higher in plasma lipids in formula fed than in breast-fed infants, meanwhile values of the intermediary metabolites of LCP synthesis did not differ between the two groups. Percentage contributions of arachidonic acid were higher in breast-fed than in formula fed infants at the ages of 2 weeks (PL: 9.39 +/- 1.00 vs. 6.91 +/- 0.38, TG: 0.61 +/- 0.03 vs. 0.41 +/- 0.05, %weight/weight, mean +/- SEM), 1 month (PL: 9.06 +/- 1.04 vs. 6.16 +/- 0.35, TG: 0.62 +/- 0.10 vs. 0.32 +/- 0.04, STE: 4.50 +/- 0.45 vs. 2.84 +/- 0.39) and 2 months (PL: 8.41 +/- 1.19 vs. 5.74 +/- 0.37). Similarly, docosahexaenoic acid values were at the ages of 1 month (PL: 1.94 +/- 0.21 vs. 1.19 +/- 0.21, TG: 0.12 +/- 0.03 vs. 0.04 +/- 0.02) and 2 months (PL: 2.02 +/- 0.36 vs. 0.99 +/- 0.07) significantly higher in breast-fed infants than in those receiving formula.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in betaine-homocysteine methyltransferase expression, ER stress response and liver injury between alcohol-fed mice and rats

PubMed Central

Shinohara, Masao; Ji, Cheng; Kaplowitz, Neil

2009-01-01

Chronic ethanol infusion resulted in greater serum ALT elevation, lipid accumulation, necroinflammation, and focal hepatic cell death in mice than rats. Mice exhibited a remarkable hyperhomocysteinemia but no increase was seen in rats. Similarly, a high methionine low folate diet (HMLF) induced less steatosis, serum ALT increase, and hyperhomocysteinemia in rats than in mice. Western blot analysis of betaine homocysteine methyltransferase (BHMT) expression showed that rats fed either ethanol or HMLF had significantly increased BHMT expression which did not occur in mice. Nuclear NFκB p65 was increased in mouse in response to alcohol feeding. The human BHMT promoter was repressed by homocysteine in mouse hepatocytes but not rat hepatocytes. BHMT induction was faster and greater in primary rat hepatocytes than mouse hepatocytes in response to exogenous homocysteine exposure. Mice fed ethanol i.g. exhibited an increase in GRP78 and IRE1 which was not seen in the rat and SREBP-1 was increased to a greater extent in mice than rats. Thus, rats are more resistant to ethanol induced steatosis, ER stress and hyperhomocysteinemia and this correlates with induction of BHMT in rats. These findings support the hypothesis that a critical factor in the pathogenesis of alcoholic liver injury is the enhanced ability of rat or impaired ability of mouse to up-regulate BHMT which prevents hyperhomocysteinemia, ER stress and liver injury. PMID:20069651

Spinal cord-specific deletion of the glutamate transporter GLT1 causes motor neuron death in mice.

PubMed

Sugiyama, Kaori; Tanaka, Kohichi

2018-03-04

Amyotrophic lateral sclerosis (ALS) is a chronic neurodegenerative disorder characterized by the selective loss of motor neurons. The precise mechanisms that cause the selective death of motor neurons remain unclear, but a growing body of evidence suggests that glutamate-mediated excitotoxicity has been considered to play an important role in the mechanisms of motor neuron degeneration in ALS. Reductions in glutamate transporter GLT1 have been reported in animal models of ALS and the motor cortex and spinal cord of ALS patients. However, it remains unknown whether the reduction in GLT1 has a primary role in the induction of motor neuron degeneration in ALS. Here, we generated conditional knockout mice that lacked GLT1 specifically in the spinal cord by crossing floxed-GLT1 mice and Hoxb8-Cre mice. Hoxb8-Cre/GLT1 flox/flox mice showed motor deficits and motor neuron loss. Thus, loss of the glial glutamate transporter GLT1 is sufficient to cause motor neuron death in mice. Copyright © 2018 Elsevier Inc. All rights reserved.

Wireless and Powerless Sensing Node System Developed for Monitoring Motors.

PubMed

Lee, Dasheng

2008-08-27

Reliability and maintainability of tooling systems can be improved through condition monitoring of motors. However, it is difficult to deploy sensor nodes due to the harsh environment of industrial plants. Sensor cables are easily damaged, which renders the monitoring system deployed to assure the machine's reliability itself unreliable. A wireless and powerless sensing node integrated with a MEMS (Micro Electro-Mechanical System) sensor, a signal processor, a communication module, and a self-powered generator was developed in this study for implementation of an easily mounted network sensor for monitoring motors. A specially designed communication module transmits a sequence of electromagnetic (EM) pulses in response to the sensor signals. The EM pulses can penetrate through the machine's metal case and delivers signals from the sensor inside the motor to the external data acquisition center. By using induction power, which is generated by the motor's shaft rotation, the sensor node is self-sustaining; therefore, no power line is required. A monitoring system, equipped with novel sensing nodes, was constructed to test its performance. The test results illustrate that, the novel sensing node developed in this study can effectively enhance the reliability of the motor monitoring system and it is expected to be a valuable technology, which will be available to the plant for implementation in a reliable motor management program.

Wireless and Powerless Sensing Node System Developed for Monitoring Motors

PubMed Central

Lee, Dasheng

2008-01-01

Reliability and maintainability of tooling systems can be improved through condition monitoring of motors. However, it is difficult to deploy sensor nodes due to the harsh environment of industrial plants. Sensor cables are easily damaged, which renders the monitoring system deployed to assure the machine's reliability itself unreliable. A wireless and powerless sensing node integrated with a MEMS (Micro Electro-Mechanical System) sensor, a signal processor, a communication module, and a self-powered generator was developed in this study for implementation of an easily mounted network sensor for monitoring motors. A specially designed communication module transmits a sequence of electromagnetic (EM) pulses in response to the sensor signals. The EM pulses can penetrate through the machine's metal case and delivers signals from the sensor inside the motor to the external data acquisition center. By using induction power, which is generated by the motor's shaft rotation, the sensor node is self-sustaining; therefore, no power line is required. A monitoring system, equipped with novel sensing nodes, was constructed to test its performance. The test results illustrate that, the novel sensing node developed in this study can effectively enhance the reliability of the motor monitoring system and it is expected to be a valuable technology, which will be available to the plant for implementation in a reliable motor management program. PMID:27873798

Performance of broiler chickens fed diets supplemented with a direct-fed microbial.

PubMed

Angel, R; Dalloul, R A; Doerr, J

2005-08-01

From hatch to 18 d of age broilers were fed starter diets with (0.9 kg/ton) or without direct fed microbial (DFM). At 18 d, birds were weighed and, within DFM treatment (trt), randomly assigned to battery pens. In Exp 1, a 2 x 2 factorial arrangement of nutrient density [control (C, 19.3% protein (CP), 0.84%, Ca 0.37% nonphytin P (nPP); and 17.1% CP, 0.8% Ca, and 0.3% nPP in the grower (Gr) and finisher (Fn) diets, respectively) and moderate (M) (17% CP, 0.69% Ca, 0.30% nPP; 15% CP, 0.66% Ca, 0.25% nPP in the Gr and Fn diets, respectively)] and DFM concentration [0 or 0.9 kg/ton (++)] was used. Exp 2 was a 2 (DSM at 0 and 0.45 kg/ton) x 3 (nutrient densities) factorial. Exp 2 included a low (L) nutrient density that differed from diet M only in Ca and nPP concentrations and an added trt, diet M with 0.45 kg/ ton DFM as in Exp 1. At the end of the Gr and Fn weight, feed efficiency, apparent nutrient retention were determined, and 4 birds per pen were sampled for tibia ash. In Exp 2, gains in the Gr phase were 1,122.0, 983.7, 1,121.5, 930.7, and 1,151.5 g in birds fed the C, M, M+, L, and L+ diets, respectively. Addition of DFM to the M diet overcame the negative effect of nutrient concentration on performance but not when the L diet was fed. Nutrient level and DFM affected apparent protein, Ca, and P retention at 32 or 42 d of age with retention increasing as nutrient level decreased and with DFM added to the diet. Ca and P retention at 28 d (Exp 1) was higher in birds fed M++ (45.8 and 46%, respectively) than in those fed the C diet (38.7 and 40.0%, respectively). Feeding the M and L diets resulted in lower tibia ash than that of birds fed the C diet, but the addition of DFM to low nutrient diets overcame this negative effect.

CoQ10 plasmatic levels in breast-fed infants compared to formula-fed infants.

PubMed

Compagnoni, G; Giuffrè, B; Lista, G; Mosca, F; Marini, A

2004-01-01

Coenzyme Q10 has been recognized as an important antioxidant factor besides its main role in bioenergetic metabolism. CoQ10 tissue levels depend both on exogenous dietetic intake and on endogenous biosynthesis, as this compound can be partly synthesized in human cells. Q10 plasma levels reflect the tissue content of the coenzyme and can be used to evaluate the presence of this compound in the human organism. Aim of the study was to measure CoQ10 plasmatic levels in a newborn breast-fed population and to compare them to CoQ10 levels in a newborn formula-fed population in order to verify whether changes in CoQ10 plasmatic contents could be related to a different dietetic intakes. We measured CoQ10 plasmatic levels in 25 healthy term neonates with different dietetic intakes: 15 breast-fed and 10 bottle-fed with a common infant formula. These infants were evaluated prospectively during the first month of life. The analyses were performed on the mothers' blood samples and cord blood samples at the time of delivery, then on infants at 4 and 28 days of age. Our results showed markedly reduced Q10 levels in cord blood samples compared to maternal Q10 plasmatic levels at the time of delivery, suggesting placental impermeability towards this molecule or increased fetal utilization during labor and delivery. At 4 days of age Q10 levels had increased in both groups of neonates, but significantly more in breast-fed infants compared to formula-fed babies (p <0.05). At 4 weeks of age no significant changes occurred in breast-fed infants, while values increased significantly in formula-fed infants (p <0.05). The content of Q10 in breast milk samples was lower than in infant formula. The results of this study show that CoQ10 plasmatic levels are at least partly influenced by the exogenous dietetic supply.

Converging Mechanisms of p53 Activation Drive Motor Neuron Degeneration in Spinal Muscular Atrophy.

PubMed

Simon, Christian M; Dai, Ya; Van Alstyne, Meaghan; Koutsioumpa, Charalampia; Pagiazitis, John G; Chalif, Joshua I; Wang, Xiaojian; Rabinowitz, Joseph E; Henderson, Christopher E; Pellizzoni, Livio; Mentis, George Z

2017-12-26

The hallmark of spinal muscular atrophy (SMA), an inherited disease caused by ubiquitous deficiency in the SMN protein, is the selective degeneration of subsets of spinal motor neurons. Here, we show that cell-autonomous activation of p53 occurs in vulnerable but not resistant motor neurons of SMA mice at pre-symptomatic stages. Moreover, pharmacological or genetic inhibition of p53 prevents motor neuron death, demonstrating that induction of p53 signaling drives neurodegeneration. At late disease stages, however, nuclear accumulation of p53 extends to resistant motor neurons and spinal interneurons but is not associated with cell death. Importantly, we identify phosphorylation of serine 18 as a specific post-translational modification of p53 that exclusively marks vulnerable SMA motor neurons and provide evidence that amino-terminal phosphorylation of p53 is required for the neurodegenerative process. Our findings indicate that distinct events induced by SMN deficiency converge on p53 to trigger selective death of vulnerable SMA motor neurons. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

TORO II simulations of induction heating in ferromagnetic materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adkins, D.R.; Gartling, D.K.; Kelley, J.B.

TORO II is a finite element computer program that is used in the simulation of electric and magnetic fields. This code, which was developed at Sandia National Laboratories, has been coupled with a finite element thermal code, COYOTE II, to predict temperature profiles in inductively heated parts. The development of an effective technique to account for the nonlinear behavior of the magnetic permeability in ferromagnetic parts is one of the more difficult aspects of solving induction heating problems. In the TORO II code, nonlinear, spatially varying magnetic permeability is approximated by an effective permeability on an element-by-element basis that effectivelymore » provides the same energy deposition that is produced when the true permeability is used. This approximation has been found to give an accurate estimate of the volumetric heating distribution in the part, and predicted temperature distributions have been experimentally verified using a medium carbon steel and a 10kW industrial induction heating unit. Work on the model was funded through a Cooperative Research and Development Agreement (CRADA) between the Department of Energy and General Motors` Delphi Saginaw Steering Systems.« less

Breast-feeding at 12 months of age and dietary habits among breast-fed and non-breast-fed infants.

PubMed

Lande, Britt; Andersen, Lene Frost; Veierød, Marit B; Baerug, Anne; Johansson, Lars; Trygg, Kerstin U; Bjørneboe, Gunn-Elin Aa

2004-06-01

To analyse factors associated with breast-feeding and use of sweetened drinks at 12 months, and to compare dietary habits among breast-fed and non-breast-fed infants. Data were collected by a semi-quantitative food-frequency questionnaire filled in by the parents. National dietary survey in Norway. In total, 1932 12-month-old infants were included. At 12 months, 36% of the infants were breast-fed. The odds of breast-feeding at this age were more than doubled both for mothers > or =35 years compared with mothers <25 years and for mothers in the highest educational group compared with mothers in the lowest. A negative association was found for maternal smoking, and the odds of breast-feeding were 40% lower for mothers who smoked than for non-smokers. Some dietary differences were observed between breast-fed and non-breast-fed infants apart from intake of milk. In particular, breast-fed infants had a significantly lower daily intake of sweetened drinks than non-breast-fed infants and a 16% lower mean daily intake of added sugars (P<0.001). Furthermore, breast-fed infants had 30% higher odds of not receiving sweetened drinks daily, compared with non-breast-fed infants. Maternal age, education and smoking status were important factors for breast-feeding at 12 months. Breast-fed infants had lower intakes of sweetened drinks and added sugars than non-breast-fed infants. From a public health perspective, continued promotion of breast-feeding is needed to reduce inequalities in breast-feeding. Moreover, prevention of high intakes of sweetened drinks and added sugars should start in infancy.

The effect of subclinical infantile thiamine deficiency on motor function in preschool children.

PubMed

Harel, Yael; Zuk, Luba; Guindy, Michal; Nakar, Orly; Lotan, Dafna; Fattal-Valevski, Aviva

2017-10-01

We investigated the long-term implications of infantile thiamine (vitamin B1) deficiency on motor function in preschoolers who had been fed during the first 2 years of life with a faulty milk substitute. In this retrospective cohort study, 39 children aged 5-6 years who had been exposed to a thiamine-deficient formula during infancy were compared with 30 age-matched healthy children with unremarkable infant nutritional history. The motor function of the participants was evaluated with The Movement Assessment Battery for Children (M-ABC) and the Zuk Assessment. Both evaluation tools revealed statistically significant differences between the exposed and unexposed groups for gross and fine motor development (p < .001, ball skills p = .01) and grapho-motor development (p = .004). The differences were especially noteworthy on M-ABC testing for balance control functioning (p < .001, OR 5.4; 95% CI 3.4-7.4) and fine motor skills (p < .001, OR 3.2; 95% CI 1.8-4.6). In the exposed group, both assessments concurred on the high rate of children exhibiting motor function difficulties in comparison to unexposed group (M-ABC: 56% vs. 10%, Zuk Assessment: 59% vs. 3%, p < .001). Thiamine deficiency in infancy has long-term implications on gross and fine motor function and balance skills in childhood, thiamine having a crucial role in normal motor development. The study emphasizes the importance of proper infant feeding and regulatory control of breast milk substitutes. © 2017 John Wiley & Sons Ltd.

Optimization of rotor shaft shrink fit method for motor using "Robust design"

NASA Astrophysics Data System (ADS)

Toma, Eiji

2018-01-01

This research is collaborative investigation with the general-purpose motor manufacturer. To review construction method in production process, we applied the parameter design method of quality engineering and tried to approach the optimization of construction method. Conventionally, press-fitting method has been adopted in process of fitting rotor core and shaft which is main component of motor, but quality defects such as core shaft deflection occurred at the time of press fitting. In this research, as a result of optimization design of "shrink fitting method by high-frequency induction heating" devised as a new construction method, its construction method was feasible, and it was possible to extract the optimum processing condition.

The Stratospheric Kinetic Inductance Polarimeter (SKIP)

NASA Astrophysics Data System (ADS)

Flanigan, Daniel; Ade, P.; Araujo, D.; Bradford, K. J.; Chapman, D.; Che, G.; Day, P.; Didier, J.; Doyle, S.; Eriksen, H.; Groppi, C. E.; Hillbrand, S. N.; Johnson, B.; Jones, G.; Limon, M.; Mauskopf, P.; McCarrick, H.; Miller, A. D.; Mroczkowski, T.; Reichborn-Kjennerud, B.; Smiley, B.; Sobrin, J.; Wehus, I. K.; Zmuidzinas, J.

2014-01-01

We discuss the Stratospheric Kinetic Inductance Polarimeter (SKIP). SKIP is a proposed balloon-borne experiment designed to study the cosmic microwave background, the cosmic infrared background, and Galactic dust emission by observing 1100 square degrees of sky in the Northern Hemisphere with launches from Kiruna, Sweden. The instrument contains 2317 single-polarization, horn-coupled, aluminum lumped-element kinetic inductance detectors (LEKIDs), which will be maintained at 100 mK by an adiabatic demagnetization refrigerator. The polarimeter will operate in two configurations, one sensitive to a spectral band centered on 150 GHz and the other sensitive to 260 and 350 GHz bands. The detector readout system is based on the ROACH-1 board, and the detectors will be biased below 300 MHz. The detector array is fed by an F/2.4 crossed-Dragone telescope with a 500 mm aperture yielding a 15 arcminute full-width half-maximum beam at 150 GHz. To minimize detector loading and maximize sensitivity, the entire optical system will be cooled to 1 K. Linearly polarized sky signals will be modulated with a metal-mesh half-wave plate that is mounted at the telescope aperture and is rotated on a superconducting magnetic bearing. The observation program consists of two or more five-day flights, and 150 GHz observations are planned to begin in 2017.

On the theory of 3-phase squirrel-cage induction motors including space harmonics and mutual slotting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Papp, G.C.

1991-03-01

In this paper general equations for the asynchronous squirrel-cage motor which contain the influence of space harmonics and the mutual slotting are derived by using among others the power-invariant symmetrical component transformation and a time-dependent transformation with which, under certain circumstances, the rotor-position angle can be removed from the coefficient matrix. The developed models implemented in a machine-independent computer program form powerful tools, with which the influence of space harmonics in relation to the geometric data of specific motors can be analyzed for steady-state and transient performances.

Reward improves long-term retention of a motor memory through induction of offline memory gains.

PubMed

Abe, Mitsunari; Schambra, Heidi; Wassermann, Eric M; Luckenbaugh, Dave; Schweighofer, Nicolas; Cohen, Leonardo G

2011-04-12

In humans, training in which good performance is rewarded or bad performance punished results in transient behavioral improvements. The relative effects of reward and punishment on consolidation and long-term retention, critical behavioral stages for successful learning, are not known. Here, we investigated the effects of reward and punishment on these different stages of human motor skill learning. We studied healthy subjects who trained on a motor task under rewarded, punished, or neutral control conditions. Performance was tested before and immediately, 6 hr, 24 hr, and 30 days after training in the absence of reward or punishment. Performance improvements immediately after training were comparable in the three groups. At 6 hr, the rewarded group maintained performance gains, whereas the other two groups experienced significant forgetting. At 24 hr, the reward group showed significant offline (posttraining) improvements, whereas the other two groups did not. At 30 days, the rewarded group retained the gains identified at 24 hr, whereas the other two groups experienced significant forgetting. We conclude that training under rewarded conditions is more effective than training under punished or neutral conditions in eliciting lasting motor learning, an advantage driven by offline memory gains that persist over time. Copyright © 2011 Elsevier Ltd. All rights reserved.

Molecular Control of the Induction of Alcohol Dehydrogenase by Ethanol in Drosophila Melanogaster Larvae

PubMed Central

Kapoun, A. M.; Geer, B. W.; Heinstra, PWH.; Corbin, V.; McKechnie, S. W.

1990-01-01

The activity of alcohol dehydrogenase (ADH:EC 1.1.1.1), the initial enzyme in the major pathway for ethanol degradation, is induced in Drosophila melanogaster larvae by low concentrations of dietary ethanol. Two lines of evidence indicate that the metabolic products of the ADH pathway for ethanol degradation are not directly involved in the induction of Adh. First, the accumulation of the proximal transcript in Adh(n2) larvae was increased when the intracellular level of ethanol was elevated. In addition, the ADH activity, the proximal Adh mRNA, and the intracellular concentration of ethanol were elevated coordinately in wild-type larvae fed hexadeuterated-ethanol, which is metabolized more slowly than normal ethanol. An examination of P element transformant lines with specific deletions in the 5' regulatory DNA of the Adh gene showed that the DNA sequence between +604 and +634 of the start site of transcription from the distal promoter was essential for this induction. The DNA sequence between -660 and about -5000 of the distal transcript start site was important for the down-regulation of the induction response. PMID:2157627

Cyclic phosphatidic acid treatment suppress cuprizone-induced demyelination and motor dysfunction in mice.

PubMed

Yamamoto, Shinji; Gotoh, Mari; Kawamura, Yuuki; Yamashina, Kota; Yagishita, Sosuke; Awaji, Takeo; Tanaka, Motomu; Maruyama, Kei; Murakami-Murofushi, Kimiko; Yoshikawa, Keisuke

2014-10-15

Multiple sclerosis is a chronic demyelinating disease of the central nervous system leading to progressive cognitive and motor dysfunction, which is characterized by neuroinflammation, demyelination, astrogliosis, loss of oligodendrocytes, and axonal pathologies. Cyclic phosphatidic acid (cPA) is a naturally occurring phospholipid mediator with a unique cyclic phosphate ring structure at the sn-2 and sn-3 positions of the glycerol backbone. cPA elicits a neurotrophin-like action and protects hippocampal neurons from ischemia-induced delayed neuronal death. In this study, we investigated the effects of cPA on cuprizone-induced demyelination, which is a model of multiple sclerosis. Mice were fed a diet containing 0.2% cuprizone for 5 weeks, which induces severe demyelination, astrocyte and microglial activation, and motor dysfunction. Simultaneous administration of cPA effectively attenuated cuprizone-induced demyelination, glial activation, and motor dysfunction. These data indicate that cPA may be a useful treatment to reduce the extent of demyelination and the severity of motor dysfunction in multiple sclerosis. cPA is a potential lead compound in the development of drugs for the treatment of this devastating disease. Copyright © 2014 Elsevier B.V. All rights reserved.

Effect of phase advance on the brushless dc motor torque speed respond

NASA Astrophysics Data System (ADS)

Mohd, M. S.; Karsiti, M. N.; Mohd, M. S.

2015-12-01

Brushless direct current (BLDC) motor is widely used in small and medium sized electric vehicles as it exhibit highest specific power and thermal efficiency as compared to the induction motor. Permanent magnets BLDC rotor create a constant magnetic flux, which limit the motor top speed. As the back electromotive force (EMF) voltage increases proportionally with motor rotational speed and it approaches the amplitude of the input voltage, the phase current amplitude will reach zero. By advancing the phase current, it is possible to extend the maximum speed of the BLDC motor beyond the rated top speed. This will allow smaller BLDC motor to be used in small electric vehicles (EV) and in larger applications will allow the use of BLDC motor without the use of multispeed transmission unit for high speed operation. However, increasing the speed of BLDC will affect the torque speed response. The torque output will decrease as speed increases. Adjusting the phase angle will affect the speed of the motor as each coil is energized earlier than the corresponding rise in the back emf of the coil. This paper discusses the phase advance strategy of Brushless DC motor by phase angle manipulation approaches using external hall sensors. Tests have been performed at different phase advance angles in advance and retard positions for different voltage levels applied. The objective is to create the external hall sensor system to commutate the BLDC motor, to establish the phase advance of the BLDC by varying the phase angle through external hall sensor manipulation, observe the respond of the motor while applying the phase advance by hall sensor adjustment.

Reproduction and health of mallards fed endrin

USGS Publications Warehouse

Spann, J.W.; Heinz, G.H.; Hulse, C.S.

1986-01-01

Concentrations of 0, 1 and 3 ppm endrin in dry duck mash were fed to mallards (Anas platyrhynchos) starting in December, and health and reproduction were measured the following spring and summer. One male fed 3 ppm endrin died with 2.0 ppm endrin (wet weight), a diagnostically lethal level, in its brain. Birds fed 1 ppm endrin reproduced as well as, if not better than, controls. Birds fed 1 ppm endrin had significantly greater hatching success of fertile eggs than did those fed 0 or 3 ppm, and their clutches hatched significantly earlier than did those of birds fed 3 ppm. Mallards fed 3 ppm endrin appeared to reproduce more poorly than controls, but this finding must be regarded with caution because the results of statistical tests often were not significant. Endrin accumulated in eggs to a mean of 1.1 and 2.9 ppm (wet weight) when fed to hens at 1 and 3 ppm. The concentration of endrin in the cacasses of adults was similar to that in eggs, but the concentration in the fat of adults was about 4 to 7 times higher than in eggs.

Rapid transient isoform-specific neuregulin1 transcription in motor neurons is regulated by neurotrophic factors and axon-target interactions.

PubMed

Wang, Jiajing; Hmadcha, Abdelkrim; Zakarian, Vaagn; Song, Fei; Loeb, Jeffrey A

2015-09-01

The neuregulins (NRGs) are a family of alternatively spliced factors that play important roles in nervous system development and disease. In motor neurons, NRG1 expression is regulated by activity and neurotrophic factors, however, little is known about what controls isoform-specific transcription. Here we show that NRG1 expression in the chick embryo increases in motor neurons that have extended their axons and that limb bud ablation before motor axon outgrowth prevents this induction, suggesting a trophic role from the developing limb. Consistently, NRG1 induction after limb bud ablation can be rescued by adding back the neurotrophic factors BDNF and GDNF. Mechanistically, BDNF induces a rapid and transient increase in type I and type III NRG1 mRNAs that peak at 4h in rat embryonic ventral spinal cord cultures. Blocking MAPK or PI3K signaling or blocking transcription with Actinomycin D blocks BDNF induced NRG1 gene induction. BDNF had no effect on mRNA degradation, suggesting that transcriptional activation rather than message stability is important. Furthermore, BDNF activates a reporter construct that includes 700bp upstream of the type I NRG1 start site. Protein synthesis is also required for type I NRG1 mRNA transcription as cycloheximide produced a super-induction of type I, but not type III NRG1 mRNA, possibly through a mechanism involving sustained activation of MAPK and PI3K. These results reveal the existence of highly responsive, transient transcriptional regulatory mechanisms that differentially modulate NRG1 isoform expression as a function of extracellular and intracellular signaling cascades and mediated by neurotrophic factors and axon-target interactions. Copyright © 2015 Elsevier Inc. All rights reserved.

Smart pitch control strategy for wind generation system using doubly fed induction generator

NASA Astrophysics Data System (ADS)

Raza, Syed Ahmed

A smart pitch control strategy for a variable speed doubly fed wind generation system is presented in this thesis. A complete dynamic model of DFIG system is developed. The model consists of the generator, wind turbine, aerodynamic and the converter system. The strategy proposed includes the use of adaptive neural network to generate optimized controller gains for pitch control. This involves the generation of controller parameters of pitch controller making use of differential evolution intelligent technique. Training of the back propagation neural network has been carried out for the development of an adaptive neural network. This tunes the weights of the network according to the system states in a variable wind speed environment. Four cases have been taken to test the pitch controller which includes step and sinusoidal changes in wind speeds. The step change is composed of both step up and step down changes in wind speeds. The last case makes use of scaled wind data collected from the wind turbine installed at King Fahd University beach front. Simulation studies show that the differential evolution based adaptive neural network is capable of generating the appropriate control to deliver the maximum possible aerodynamic power available from wind to the generator in an efficient manner by minimizing the transients.

High dose lycopene supplementation increases hepatic cytochrome P4502E1 protein and inflammation in alcohol-fed rats.

PubMed

Veeramachaneni, Sudipta; Ausman, Lynne M; Choi, Sang Woon; Russell, Robert M; Wang, Xiang-Dong

2008-07-01

Recent in vitro evidence suggests that the antioxidant lycopene can prevent alcohol-induced oxidative stress and inflammation. However, knowledge of possible interactions in vivo between escalating doses of lycopene and chronic alcohol ingestion are lacking. In this study, we investigated potential interactions between alcohol ingestion and lycopene supplementation and their effect on hepatic lycopene concentration, cytochrome P4502E1 (CYP2E1) induction, and inflammation. Fischer 344 rats (6 groups, n = 10 per group) were fed either a liquid ethanol Lieber-DeCarli diet or a control diet (isocaloric maltodextrin substituted for ethanol) with or without lycopene supplementation at 2 doses (1.1 or 3.3 mg x kg body weight(-1) x d(-1)) for 11 wk. Plasma and hepatic concentrations of lycopene isomers were assessed by HPLC analysis. We examined expressions of hepatic CYP2E1 and tumor necrosis factor-alpha (TNFalpha) and the incidence of hepatic inflammatory foci. Both plasma and hepatic lycopene concentrations were greater in alcohol-fed rats than in control rats supplemented with identical doses of lycopene. In contrast, alcohol-fed rats had a lower percentage of lycopene cis isomers in the plasma and the liver compared with control rats fed the same dose of lycopene. Notably, lycopene supplementation at the higher dose significantly induced hepatic CYP2E1 protein, TNFalpha mRNA, and the incidence of inflammatory foci in the alcohol-fed rats but not in the control rats. These data indicate an interaction between chronic alcohol ingestion and lycopene supplementation and suggest a need for caution among individuals consuming high amounts of both alcohol and lycopene.

A sensorimotor theory of temporal tracking and beat induction.

PubMed

Todd, N P McAngus; Lee, C S; O'Boyle, D J

2002-02-01

In this paper, we develop a theory of the neurobiological basis of temporal tracking and beat induction as a form of sensory-guided action. We propose three principal components for the neurological architecture of temporal tracking: (1) the central auditory system, which represents the temporal information in the input signal in the form of a modulation power spectrum; (2) the musculoskeletal system, which carries out the action and (3) a controller, in the form of a parieto-cerebellar-frontal loop, which carries out the synchronisation between input and output by means of an internal model of the musculoskeletal dynamics. The theory is implemented in the form of a computational algorithm which takes sound samples as input and synchronises a simple linear mass-spring-damper system to simulate audio-motor synchronisation. The model may be applied to both the tracking of isochronous click sequences and beat induction in rhythmic music or speech, and also accounts for the approximate Weberian property of timing.

Induction motor speed drive improvement using fuzzy IP-self-tuning controller. A real time implementation.

PubMed

Lokriti, Abdesslam; Salhi, Issam; Doubabi, Said; Zidani, Youssef

2013-05-01

An IP-self-tuning controller tuned by a fuzzy adjustor, is proposed to improve induction machine speed control. The interest of such controller is the possibility to adjust only one gain, instead of two gains for the case of the PI-self-tuning controllers commonly used in the literature. This paper presents simulation and experimental results. These latter were obtained by practical implementation on a DSPace 1104 board of three different speed controllers (the classical IP, the fuzzy-like-PI and the IP-self-tuning), for a 1.5KW induction machine. The paper presents different tests used to compare the performances of the proposed controller to the two others in terms of computation time, tracking performances and disturbances rejection. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

Relevance of a Hypersaline Sodium-Rich Naturally Sparkling Mineral Water to the Protection against Metabolic Syndrome Induction in Fructose-Fed Sprague-Dawley Rats: A Biochemical, Metabolic, and Redox Approach.

PubMed

Pereira, Cidália Dionísio; Severo, Milton; Araújo, João Ricardo; Guimarães, João Tiago; Pestana, Diogo; Santos, Alejandro; Ferreira, Rita; Ascensão, António; Magalhães, José; Azevedo, Isabel; Monteiro, Rosário; Martins, Maria João

2014-01-01

The Metabolic Syndrome increases the risk for atherosclerotic cardiovascular disease and type 2 Diabetes Mellitus. Increased fructose consumption and/or mineral deficiency have been associated with Metabolic Syndrome development. This study aimed to investigate the effects of 8 weeks consumption of a hypersaline sodium-rich naturally sparkling mineral water on 10% fructose-fed Sprague-Dawley rats (Metabolic Syndrome animal model). The ingestion of the mineral water (rich in sodium bicarbonate and with higher potassium, calcium, and magnesium content than the tap water used as control) reduced/prevented not only the fructose-induced increase of heart rate, plasma triacylglycerols, insulin and leptin levels, hepatic catalase activity, and organ weight to body weight ratios (for liver and both kidneys) but also the decrease of hepatic glutathione peroxidase activity and oxidized glutathione content. This mineral-rich water seems to have potential to prevent Metabolic Syndrome induction by fructose. We hypothesize that its regular intake in the context of modern diets, which have a general acidic character interfering with mineral homeostasis and are poor in micronutrients, namely potassium, calcium, and magnesium, could add surplus value and attenuate imbalances, thus contributing to metabolic and redox health and, consequently, decreasing the risk for atherosclerotic cardiovascular disease.

Role of heat shock protein Hsp25 in the response of the orofacial nuclei motor system to physiological stress

NASA Technical Reports Server (NTRS)

Murashov, A. K.; Talebian, S.; Wolgemuth, D. J.

1998-01-01

Although expression of the small heat shock protein family member Hsp25 has been previously observed in the central nervous system (CNS), both constitutively and upon induction, its function in the CNS remains far from clear. In the present study we have characterized the spatial pattern of expression of Hsp25 in the normal adult mouse brain as well as the changes in expression patterns induced by subjecting mice to experimental hyperthermia or hypoxia. Immunohistochemical analysis revealed a surprisingly restricted pattern of constitutive expression of Hsp25 in the brain, limited to the facial, trigeminal, ambiguus, hypoglossal and vagal motor nuclei of the brainstem. After hyperthermia or hypoxia treatment, significant increases in the levels of Hsp25 were observed in these same areas and also in fibers of the facial and trigeminal nerve tracts. Immunoblot analysis of protein lysates from brainstem also showed the same pattern of induction of Hsp25. Surprisingly, no other area in the brain showed expression of Hsp25, in either control or stressed animals. The highly restricted expression of Hsp25 implies that this protein may have a specific physiological role in the orofacial motor nuclei, which govern precise coordination between muscles of mastication and the pharynx, larynx, and face. Its rapid induction after stress further suggests that Hsp25 may serve as a specific molecular chaperone in the lower cholinergic motor neurons and along their fibers under conditions of stress or injury. Copyright 1998 Elsevier Science B.V.

Reproduction in mallards fed selenium

USGS Publications Warehouse

Heinz, G.H.; Hoffman, D.J.; Krynitsky, A.J.; Weller, D.M.G.

1987-01-01

Mallards (Anas platyrhynchos) were fed diets containing 1, 5, 10, 25 or 100 ppm selenium as sodium selenite, a diet containing 10 ppm selenium as seleno-DL-methionine or a control diet. There were no effects of 1, 5 or 10 ppm selenium as sodium selenite on either weight or survival of adults or on reproductive success, and there did not appear to be a dose-response relationship at these lower levels. The 100 ppm selenium diet killed 11 of 12 adults; one adult male fed 25 ppm selenium died. Selenium at 25 and 100 ppm caused weight loss in adults. Females fed 25 ppm selenium took longer to begin laying eggs and intervals between eggs were longer than in females in other treatment groups. Hatching success appeared to be reduced in birds fed 10 ppm selenium at selenomethionine, but the reduction was not statistically significant. The survival of ducklings and the mean number of 21-d-old ducklings produced per female were reduced in the 25 ppm selenium as sodium selenite group and the 10 ppm selenium as selenomethionine group. Egg weights were not affected by any selenium treatment, but 25 ppm selenium lowered the Ratcliffe Index. Duckling weights at hatching and at 21 d of age were reduced 28 and 36%, respectively, in birds fed 25 ppm selenium, as compared with controls. Body weights measured on day 21 were lower for ducklings fed 10 ppm selenium as selenomethionine than in some other groups. Selenium in concentrations of 10 and 25 ppm as sodium selenite caused mainly embryotoxic effects, whereas 10 ppm as selenomethionine was more teratogenic, causing hydrocephaly, bill defects, eye defects (microphthalmia and anophthalmia) and foot and toe defects, including ectrodactyly. Selenomethionine was much more readily taken up by mallards and passed into their eggs than was sodium selenite, and a greater proportion of the selenium in the eggs ended up in the white when selenomethionine was fed. Adult males accumulated more selenium than did females, probably because of the

Efficient differentiation of mouse embryonic stem cells into motor neurons.

PubMed

Wu, Chia-Yen; Whye, Dosh; Mason, Robert W; Wang, Wenlan

2012-06-09

Direct differentiation of embryonic stem (ES) cells into functional motor neurons represents a promising resource to study disease mechanisms, to screen new drug compounds, and to develop new therapies for motor neuron diseases such as spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS). Many current protocols use a combination of retinoic acid (RA) and sonic hedgehog (Shh) to differentiate mouse embryonic stem (mES) cells into motor neurons. However, the differentiation efficiency of mES cells into motor neurons has only met with moderate success. We have developed a two-step differentiation protocol that significantly improves the differentiation efficiency compared with currently established protocols. The first step is to enhance the neuralization process by adding Noggin and fibroblast growth factors (FGFs). Noggin is a bone morphogenetic protein (BMP) antagonist and is implicated in neural induction according to the default model of neurogenesis and results in the formation of anterior neural patterning. FGF signaling acts synergistically with Noggin in inducing neural tissue formation by promoting a posterior neural identity. In this step, mES cells were primed with Noggin, bFGF, and FGF-8 for two days to promote differentiation towards neural lineages. The second step is to induce motor neuron specification. Noggin/FGFs exposed mES cells were incubated with RA and a Shh agonist, Smoothened agonist (SAG), for another 5 days to facilitate motor neuron generation. To monitor the differentiation of mESs into motor neurons, we used an ES cell line derived from a transgenic mouse expressing eGFP under the control of the motor neuron specific promoter Hb9. Using this robust protocol, we achieved 51 ± 0.8% of differentiation efficiency (n = 3; p < 0.01, Student's t-test). Results from immunofluorescent staining showed that GFP+ cells express the motor neuron specific markers, Islet-1 and choline acetyltransferase (ChAT). Our two

Research on the Control Strategy for Grid-side Converter of PWM Doubly Fed Induction Wind Power Generators

NASA Astrophysics Data System (ADS)

Liu, Yifang; Wang, Zhijie; Li, Renfu; Jiang, Xiuchen; Sheng, Gehao; Liu, Tianyu; Liu, Sanming

2017-05-01

When the grid voltage drop, over current of transient rotor and over voltage may damage the power electronic devices. The attenuation of electromagnetic torque will lead to speed up. This paper proposes an improved feed-forward control strategy and its application in the PWM converter. When the PWM converter on voltage drops, bus voltage will be more stable. So over current problems of the DFIG rotor side can be reduced, and it also can improve voltage regulation speed of the DC bus voltage and reduce the oscillation amplitude. Furthermore, the stability of doubly fed wind generator system can be improved. The simulation results verify the validity of the modified control strategy.

Breast-fed and bottle-fed infant rhesus macaques develop distinct gut microbiotas and immune systems

PubMed Central

Ardeshir, Amir; Narayan, Nicole R.; Méndez-Lagares, Gema; Lu, Ding; Rauch, Marcus; Huang, Yong; Van Rompay, Koen K. A.; Lynch, Susan V.; Hartigan-O'Connor, Dennis J.

2015-01-01

Diet has a strong influence on the intestinal microbiota in both humans and animal models. It is well established that microbial colonization is required for normal development of the immune system and that specific microbial constituents prompt the differentiation or expansion of certain immune cell subsets. Nonetheless, it has been unclear how profoundly diet might shape the primate immune system or how durable the influence might be. We show that breast-fed and bottle-fed infant rhesus macaques develop markedly different immune systems, which remain different 6 months after weaning when the animals begin receiving identical diets. In particular, breast-fed infants develop robust populations of memory T cells as well as T helper 17 (TH17) cells within the memory pool, whereas bottle-fed infants do not. These findings may partly explain the variation in human susceptibility to conditions with an immune basis, as well as the variable protection against certain infectious diseases. PMID:25186175

Translational Arrest Due to Cytoplasmic Redox Stress Delays Adaptation to Growth on Methanol and Heterologous Protein Expression in a Typical Fed-Batch Culture of Pichia pastoris

PubMed Central

Edwards-Jones, Bryn; Aw, Rochelle; Barton, Geraint R.; Tredwell, Gregory D.; Bundy, Jacob G.; Leak, David J.

2015-01-01

Results We have followed a typical fed-batch induction regime for heterologous protein production under the control of the AOX1 promoter using both microarray and metabolomic analysis. The genetic constructs involved 1 and 3 copies of the TRY1 gene, encoding human trypsinogen. In small-scale laboratory cultures, expression of the 3 copy-number construct induced the unfolded protein response (UPR) sufficiently that titres of extracellular trypsinogen were lower in the 3-copy construct than with the 1-copy construct. In the fed-batch-culture, a similar pattern was observed, with higher expression from the 1-copy construct, but in this case there was no significant induction of UPR with the 3-copy strain. Analysis of the microarray and metabolomic information indicates that the 3-copy strain was undergoing cytoplasmic redox stress at the point of induction with methanol. In this Crabtree-negative yeast, this redox stress appeared to delay the adaptation to growth on methanol and supressed heterologous protein production, probably due to a block in translation. Conclusion Although redox imbalance as a result of artificially imposed hypoxia has previously been described, this is the first time that it has been characterised as a result of a transient metabolic imbalance and shown to involve a stress response which can lead to translational arrest. Without detailed analysis of the underlying processes it could easily have been mis-interpreted as secretion stress, transmitted through the UPR. PMID:25785713

Translational arrest due to cytoplasmic redox stress delays adaptation to growth on methanol and heterologous protein expression in a typical fed-batch culture of Pichia pastoris.

PubMed

Edwards-Jones, Bryn; Aw, Rochelle; Barton, Geraint R; Tredwell, Gregory D; Bundy, Jacob G; Leak, David J

2015-01-01

We have followed a typical fed-batch induction regime for heterologous protein production under the control of the AOX1 promoter using both microarray and metabolomic analysis. The genetic constructs involved 1 and 3 copies of the TRY1 gene, encoding human trypsinogen. In small-scale laboratory cultures, expression of the 3 copy-number construct induced the unfolded protein response (UPR) sufficiently that titres of extracellular trypsinogen were lower in the 3-copy construct than with the 1-copy construct. In the fed-batch-culture, a similar pattern was observed, with higher expression from the 1-copy construct, but in this case there was no significant induction of UPR with the 3-copy strain. Analysis of the microarray and metabolomic information indicates that the 3-copy strain was undergoing cytoplasmic redox stress at the point of induction with methanol. In this Crabtree-negative yeast, this redox stress appeared to delay the adaptation to growth on methanol and supressed heterologous protein production, probably due to a block in translation. Although redox imbalance as a result of artificially imposed hypoxia has previously been described, this is the first time that it has been characterised as a result of a transient metabolic imbalance and shown to involve a stress response which can lead to translational arrest. Without detailed analysis of the underlying processes it could easily have been mis-interpreted as secretion stress, transmitted through the UPR.

Analysis and control of the vibration of doubly fed wind turbine

NASA Astrophysics Data System (ADS)

Yu, Manye; Lin, Ying

2017-01-01

The fault phenomena of the violent vibration of certain doubly-fed wind turbine were researched comprehensively, and the dynamic characteristics, load and fault conditions of the system were discussed. Firstly, the structural dynamics analysis of wind turbine is made, and the dynamics mold is built. Secondly, the vibration testing of wind turbine is done with the German test and analysis systems BBM. Thirdly, signal should be analyzed and dealt with. Based on the experiment, spectrum analysis of the motor dynamic balance can be made by using signal processing toolbox of MATLAB software, and the analysis conclusions show that the vibration of wind turbine is caused by dynamic imbalance. The results show that integrating mechanical system dynamics theory with advanced test technology can solve the vibration problem more successfully, which is important in vibration diagnosis of mechanical equipment.

A novel transient rotor current control scheme of a doubly-fed induction generator equipped with superconducting magnetic energy storage for voltage and frequency support

NASA Astrophysics Data System (ADS)

Shen, Yang-Wu; Ke, De-Ping; Sun, Yuan-Zhang; Daniel, Kirschen; Wang, Yi-Shen; Hu, Yuan-Chao

2015-07-01

A novel transient rotor current control scheme is proposed in this paper for a doubly-fed induction generator (DFIG) equipped with a superconducting magnetic energy storage (SMES) device to enhance its transient voltage and frequency support capacity during grid faults. The SMES connected to the DC-link capacitor of the DFIG is controlled to regulate the transient dc-link voltage so that the whole capacity of the grid side converter (GSC) is dedicated to injecting reactive power to the grid for the transient voltage support. However, the rotor-side converter (RSC) has different control tasks for different periods of the grid fault. Firstly, for Period I, the RSC injects the demagnetizing current to ensure the controllability of the rotor voltage. Then, since the dc stator flux degenerates rapidly in Period II, the required demagnetizing current is low in Period II and the RSC uses the spare capacity to additionally generate the reactive (priority) and active current so that the transient voltage capability is corroborated and the DFIG also positively responds to the system frequency dynamic at the earliest time. Finally, a small amount of demagnetizing current is provided after the fault clearance. Most of the RSC capacity is used to inject the active current to further support the frequency recovery of the system. Simulations are carried out on a simple power system with a wind farm. Comparisons with other commonly used control methods are performed to validate the proposed control method. Project supported by the National Natural Science Foundation of China (Grant No. 51307124) and the Major Program of the National Natural Science Foundation of China (Grant No. 51190105).

Variation in motor output and motor performance in a centrally generated motor pattern

PubMed Central

Norris, Brian J.; Doloc-Mihu, Anca; Calabrese, Ronald L.

2014-01-01

Central pattern generators (CPGs) produce motor patterns that ultimately drive motor outputs. We studied how functional motor performance is achieved, specifically, whether the variation seen in motor patterns is reflected in motor performance and whether fictive motor patterns differ from those in vivo. We used the leech heartbeat system in which a bilaterally symmetrical CPG coordinates segmental heart motor neurons and two segmented heart tubes into two mutually exclusive coordination modes: rear-to-front peristaltic on one side and nearly synchronous on the other, with regular side-to-side switches. We assessed individual variability of the motor pattern and the beat pattern in vivo. To quantify the beat pattern we imaged intact adults. To quantify the phase relations between motor neurons and heart constrictions we recorded extracellularly from two heart motor neurons and movement from the corresponding heart segments in minimally dissected leeches. Variation in the motor pattern was reflected in motor performance only in the peristaltic mode, where larger intersegmental phase differences in the motor neurons resulted in larger phase differences between heart constrictions. Fictive motor patterns differed from those in vivo only in the synchronous mode, where intersegmental phase differences in vivo had a larger front-to-rear bias and were more constrained. Additionally, load-influenced constriction timing might explain the amplification of the phase differences between heart segments in the peristaltic mode and the higher variability in motor output due to body shape assumed in this soft-bodied animal. The motor pattern determines the beat pattern, peristaltic or synchronous, but heart mechanics influence the phase relations achieved. PMID:24717348

Purmorphamine as a Shh Signaling Activator Small Molecule Promotes Motor Neuron Differentiation of Mesenchymal Stem Cells Cultured on Nanofibrous PCL Scaffold.

PubMed

Bahrami, Naghmeh; Bayat, Mohammad; Mohamadnia, Abdolreza; Khakbiz, Mehrdad; Yazdankhah, Meysam; Ai, Jafar; Ebrahimi-Barough, Somayeh

2017-09-01

There is variety of stem cell sources but problems in ethical issues, contamination, and normal karyotype cause many limitations in obtaining and using these cells. The cells in Wharton's jelly region of umbilical cord are abundant and available stem cells with low immunological incompatibility, which could be considered for cell replacement therapy. Small molecules have been presented as less expensive biologically active compounds that can regulate different developmental process. Purmorphamine (PMA) is a small molecule that, according to some studies, possesses certain differentiation effects. In this study, we investigated the effect of the PMA on Wharton's jelly mesenchymal stem cell (WJ-MSC) differentiation into motor neuronal lineages instead of sonic hedgehog (Shh) on PCL scaffold. After exposing to induction media for 15 days, the cells were characterized for expression of motor neuron markers including PAX6, NF-H, Islet1, HB9, and choline acetyl transferase (ChAT) by quantitative reverse transcription (PCR) and immunocytochemistry. Our results demonstrated that induced WJ-MSCs with PMA could significantly express motor neuron markers in RNA and protein levels 15 days post induction. These results suggested that WJ-MSCs can differentiate to motor neuron-like cells with PMA on PCL scaffold and might provide a potential source in cell therapy for nervous system.

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.

Flight Experiment Demonstration System (FEDS): Mathematical specification

NASA Technical Reports Server (NTRS)

Shank, D. E.

1984-01-01

Computational models for the flight experiment demonstration system (FEDS) code 580 were developed. The FEDS is a modification of the automated orbit determination system which was developed during 1981 and 1982. The purpose of FEDS is to demonstrate, in a simulated spacecraft environment, the feasibility of using microprocessors to perform onboard orbit determination with limited ground support.

The Fed's Year of Transition

ERIC Educational Resources Information Center

Schug, Mark C.; Niederjohn, Scott

2006-01-01

The purpose of this article is to: (1) Examine the historical development of the Federal Reserve System; (2) Provide background on Ben Bernanke, the new Fed chairman; (3) Explain the basic tools of monetary policy used by the Fed; (4) Examine the causes of the Great Depression, a topic of special interest to Bernanke; and (5) Provide some key…

Inductive reasoning.

PubMed

Hayes, Brett K; Heit, Evan; Swendsen, Haruka

2010-03-01

Inductive reasoning entails using existing knowledge or observations to make predictions about novel cases. We review recent findings in research on category-based induction as well as theoretical models of these results, including similarity-based models, connectionist networks, an account based on relevance theory, Bayesian models, and other mathematical models. A number of touchstone empirical phenomena that involve taxonomic similarity are described. We also examine phenomena involving more complex background knowledge about premises and conclusions of inductive arguments and the properties referenced. Earlier models are shown to give a good account of similarity-based phenomena but not knowledge-based phenomena. Recent models that aim to account for both similarity-based and knowledge-based phenomena are reviewed and evaluated. Among the most important new directions in induction research are a focus on induction with uncertain premise categories, the modeling of the relationship between inductive and deductive reasoning, and examination of the neural substrates of induction. A common theme in both the well-established and emerging lines of induction research is the need to develop well-articulated and empirically testable formal models of induction. Copyright © 2010 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website. Copyright © 2010 John Wiley & Sons, Ltd.

Is the Macronutrient Intake of Formula-Fed Infants Greater Than Breast-Fed Infants in Early Infancy?

PubMed Central

Hester, Shelly N.; Hustead, Deborah S.; Mackey, Amy D.; Singhal, Atul; Marriage, Barbara J.

2012-01-01

Faster weight gain early in infancy may contribute to a greater risk of later obesity in formula-fed compared to breast-fed infants. One potential explanation for the difference in weight gain is higher macronutrient intake in formula-fed infants during the first weeks of life. A systematic review was conducted using Medline to assess the macronutrient and energy content plus volume of intake in breast-fed and formula-fed infants in early infancy. All studies from healthy, term, singleton infants reporting values for the composition of breast milk during the first month of life were included. The energy content of colostrum (mean, SEM: 53.6 ± 2.5 kcal/100 mL), transitional milk (57.7 ± 4.2 kcal/100 mL), and mature milk (65.2 ± 1.1 kcal/100 mL) was lower than conventional infant formula (67 kcal/100 mL) on all days analyzed. The protein concentration of colostrum (2.5 ± 0.2 g/100 mL) and transitional milk (1.7 ± 0.1 g/100 mL) was higher than formula (1.4 g/100 mL), while the protein content of mature milk (1.3 ± 0.1 g/100 mL) was slightly lower. Formula-fed infants consume a higher volume and more energy dense milk in early life leading to faster growth which could potentially program a greater risk of long-term obesity. PMID:23056929

Reducing endoplasmic reticulum stress does not improve steatohepatitis in mice fed a methionine- and choline-deficient diet.

PubMed

Henkel, Anne S; Dewey, Amanda M; Anderson, Kristy A; Olivares, Shantel; Green, Richard M

2012-07-01

Endoplasmic reticulum (ER) stress has been implicated in the pathogenesis of nonalcoholic steatohepatitis. The ER stress response is activated in the livers of mice fed a methionine- and choline-deficient (MCD) diet, yet the role of ER stress in the pathogenesis of MCD diet-induced steatohepatitis is unknown. Using chemical chaperones on hepatic steatosis and markers of inflammation and fibrosis in mice fed a MCD diet, we aim to determine the effects of reducing ER stress. C57BL/6J mice were fed a MCD diet with or without the ER chemical chaperones 4-phenylbutyric acid (PBA) and tauroursodeoxycholic acid (TUDCA) for 2 wk. TUDCA and PBA effectively attenuated the ER stress response in MCD diet-fed mice, as evidenced by reduced protein levels of phosphorylated eukaryotic initiation factor 2α and phosphorylated JNK and suppression of mRNA levels of CCAAT/enhancer binding protein homologous protein, glucose-regulated protein 78 kDa, and X-box binding protein 1. However, PBA and TUDCA did not decrease MCD diet-induced hepatic steatosis. MCD diet-induced hepatic inflammation, as evidenced by increased plasma alanine aminotransferase and induction of hepatic TNFα expression, was also not reduced by PBA or TUDCA. PBA and TUDCA did not attenuate MCD diet-induced upregulation of the fibrosis-associated genes tissue inhibitor of metalloproteinase-1 and matrix metalloproteinase-9. ER chemical chaperones reduce MCD diet-induced ER stress, yet they do not improve MCD diet-induced hepatic steatosis, inflammation, or activation of genes associated with fibrosis. These data suggest that although the ER stress response is activated by the MCD diet, it does not have a primary role in the pathogenesis of MCD diet-induced steatohepatitis.

Formation of cortical plasticity in older adults following tDCS and motor training

PubMed Central

Goodwill, Alicia M.; Reynolds, John; Daly, Robin M.; Kidgell, Dawson J.

2013-01-01

Neurodegeneration accompanies the process of natural aging, reducing the ability to perform functional daily activities. Transcranial direct current stimulation (tDCS) alters neuronal excitability and motor performance; however its beneficial effect on the induction of primary motor cortex (M1) plasticity in older adults is unclear. Moreover, little is known as to whether the tDCS electrode arrangement differentially affects M1 plasticity and motor performance in this population. In a double-blinded, cross-over trial, we compared unilateral, bilateral and sham tDCS combined with visuomotor tracking, on M1 plasticity and motor performance of the non-dominant upper limb, immediately post and 30 min following stimulation. We found (a) unilateral and bilateral tDCS decreased tracking error by 12–22% at both time points; with sham decreasing tracking error by 10% at 30 min only, (b) at both time points, motor evoked potentials (MEPs) were facilitated (38–54%) and short-interval intracortical inhibition was released (21–36%) for unilateral and bilateral conditions relative to sham, (c) there were no differences between unilateral and bilateral conditions for any measure. These findings suggest that tDCS modulated elements of M1 plasticity, which improved motor performance irrespective of the electrode arrangement. The results provide preliminary evidence indicating that tDCS is a safe non-invasive tool to preserve or improve neurological function and motor control in older adults. PMID:24367333

Flight Experiment Demonstration System (FEDS) functional description and interface document

NASA Technical Reports Server (NTRS)

Belcher, R. C.; Shank, D. E.

1984-01-01

This document presents a functional description of the Flight Experiment Demonstration System (FEDS) and of interfaces between FEDS and external hardware and software. FEDS is a modification of the Automated Orbit Determination System (AODS). FEDS has been developed to support a ground demonstration of microprocessor-based onboard orbit determination. This document provides an overview of the structure and logic of FEDS and details the various operational procedures to build and execute FEDS. It also documents a microprocessor interface between FEDS and a TDRSS user transponder and describes a software simulator of the interface used in the development and system testing of FEDS.

Extending the Constant Power Speed Range of the Brushless DC Motor through Dual Mode Inverter Control -- Part II: Laboratory Proof-of-Principle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawler, J.S.

2001-10-29

Previous theoretical work has shown that when all loss mechanisms are neglected the constant power speed range (CPSR) of a brushless dc motor (BDCM) is infinite when the motor is driven by the dual-mode inverter control (DMIC) [1,2]. In a physical drive, losses, particularly speed-sensitive losses, will limit the CPSR to a finite value. In this paper we report the results of laboratory testing of a low-inductance, 7.5-hp BDCM driven by the DMIC. The speed rating of the test motor rotor limited the upper speed of the testing, and the results show that the CPSR of the test machine ismore » greater than 6:1 when driven by the DMIC. Current wave shape, peak, and rms values remained controlled and within rating over the entire speed range. The laboratory measurements allowed the speed-sensitive losses to be quantified and incorporated into computer simulation models, which then accurately reproduce the results of lab testing. The simulator shows that the limiting CPSR of the test motor is 8:1. These results confirm that the DMIC is capable of driving low-inductance BDCMs over the wide CPSR that would be required in electric vehicle applications.« less

A variable-speed, constant-frequency wind power generation scheme using a slip-ring induction generator

NASA Astrophysics Data System (ADS)

Velayudhan, C.; Bundell, J. H.

This paper investigates a variable-speed, constant-frequency double output induction generator which is capable of absorbing the mechanical energy from a fixed pitch wind turbine and converting it into electrical energy at constant grid voltage and frequency. Rotor power at varying voltage and frequency is either fed to electronically controlled resistances and used as heat energy or is rectified, inverted by a controllable line-commutated inverter and returned to the grid. Optimal power tracking is by means of an adaptive controller which controls the developed torque of the generator by monitoring the shaft speed.

Melodic Priming of Motor Sequence Performance: The Role of the Dorsal Premotor Cortex.

PubMed

Stephan, Marianne A; Brown, Rachel; Lega, Carlotta; Penhune, Virginia

2016-01-01

The purpose of this study was to determine whether exposure to specific auditory sequences leads to the induction of new motor memories and to investigate the role of the dorsal premotor cortex (dPMC) in this crossmodal learning process. Fifty-two young healthy non-musicians were familiarized with the sound to key-press mapping on a computer keyboard and tested on their baseline motor performance. Each participant received subsequently either continuous theta burst stimulation (cTBS) or sham stimulation over the dPMC and was then asked to remember a 12-note melody without moving. For half of the participants, the contour of the melody memorized was congruent to a subsequently performed, but never practiced, finger movement sequence (Congruent group). For the other half, the melody memorized was incongruent to the subsequent finger movement sequence (Incongruent group). Hearing a congruent melody led to significantly faster performance of a motor sequence immediately thereafter compared to hearing an incongruent melody. In addition, cTBS speeded up motor performance in both groups, possibly by relieving motor consolidation from interference by the declarative melody memorization task. Our findings substantiate recent evidence that exposure to a movement-related tone sequence can induce specific, crossmodal encoding of a movement sequence representation. They further suggest that cTBS over the dPMC may enhance early offline procedural motor skill consolidation in cognitive states where motor consolidation would normally be disturbed by concurrent declarative memory processes. These findings may contribute to a better understanding of auditory-motor system interactions and have implications for the development of new motor rehabilitation approaches using sound and non-invasive brain stimulation as neuromodulatory tools.

Induction of apoptosis by fungal culture materials containing cyclopiazonic acid and T-2 toxin in primary lymphoid organs of broiler chickens.

PubMed

Venkatesh, P Kamala; Vairamuthu, S; Balachandran, C; Manohar, B Murali; Raj, G Dhinakar

2005-04-01

Thirty-six, twenty-eight-day-old broiler chicks were randomly distributed into three groups of 12 birds each. Two groups were fed diets containing 10 ppm cyclopiazonic acid (CPA) and 1ppm T-2 toxin, respectively, to determine the mechanism of cell death in spleen and thymus at 6, 12, 24, and 36 h of post-treatment. The other group served as control. T-2 toxin treated group showed significant (P < 0.01) induction of apoptosis in thymus with peak induction at 24 h post-treatment where as, no significant differences were observed between the control and CPA groups. The CPA toxin treated group showed significant (P < 0.01) induction of apoptosis in spleen with peak induction at 24 h post-treatment. No significant differences were observed between the control and T-2 toxin group even though the latter showed a slight increase in the quantity of apoptotic cells at 36 h post-treatment in spleen. The semi-thin sections stained with toluidine blue from the spleen of CPA treated group exhibited crescent margination of chromatin against the nuclear envelope and shrinkage of lymphoid cells without any surrounding inflammation, the characteristics of apoptosis. The apoptotic thymocytes from T-2 fed birds appeared shrunken with condensed nucleus and showed crescent margination of chromatin against the nuclear envelope without any surrounding inflammation when compared with well-defined nuclei with dispersed chromatin in normal thymocytes. Ultrastructurally, splenocytes of the CPA treated group and thymocytes of the T-2 toxin treated birds showed apoptotic bodies characterized by crescent margination of the chromatin against the nuclear envelope. The study indicates that one route of the CPA and T-2 toxin induced cell death in lymphoid organs of broiler chicken is by apoptosis.

Breastfeeding duration and cognitive, language and motor development at 18 months of age: Rhea mother-child cohort in Crete, Greece.

PubMed

Leventakou, Vasiliki; Roumeliotaki, Theano; Koutra, Katerina; Vassilaki, Maria; Mantzouranis, Evangelia; Bitsios, Panos; Kogevinas, Manolis; Chatzi, Leda

2015-03-01

Breast feeding duration has been associated with improved cognitive development in children. However, few population-based prospective studies have evaluated dose-response relationships of breastfeeding duration with language and motor development at early ages, and results are discrepant. The study uses data from the prospective mother-child cohort ('Rhea' study) in Crete, Greece. 540 mother-child pairs were included in the present analysis. Information about parental and child characteristics and breastfeeding practices was obtained by interview-administered questionnaires. Trained psychologists assessed cognitive, language and motor development by using the Bayley Scales of Infant Toddler Development (3rd edition) at the age of 18 months. Duration of breast feeding was linearly positively associated with all the Bayley scales, except of gross motor. The association persisted after adjustment for potential confounders with an increase of 0.28 points in the scale of cognitive development (β=0.28; 95% CI 0.01 to 0.55), 0.29 points in the scale of receptive communication (β=0.29; 95% CI 0.04 to 0.54), 0.30 points in the scale of expressive communication (β=0.30; 95% CI 0.04 to 0.57) and 0.29 points in the scale of fine motor development (β=0.29; 95% CI 0.02 to 0.56) per accumulated month of breast feeding. Children who were breast fed longer than 6 months had a 4.44-point increase in the scale of fine motor development (β=4.44; 95% CI 0.06 to 8.82) compared with those never breast fed. Longer duration of breast feeding was associated with increased scores in cognitive, language and motor development at 18 months of age, independently from a wide range of parental and infant characteristics. Additional longitudinal studies and trials are needed to confirm these results. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Comparative Study of Fault Diagnostic Methods in Voltage Source Inverter Fed Three Phase Induction Motor Drive

NASA Astrophysics Data System (ADS)

Dhumale, R. B.; Lokhande, S. D.

2017-05-01

Three phase Pulse Width Modulation inverter plays vital role in industrial applications. The performance of inverter demeans as several types of faults take place in it. The widely used switching devices in power electronics are Insulated Gate Bipolar Transistors (IGBTs) and Metal Oxide Field Effect Transistors (MOSFET). The IGBTs faults are broadly classified as base or collector open circuit fault, misfiring fault and short circuit fault. To develop consistency and performance of inverter, knowledge of fault mode is extremely important. This paper presents the comparative study of IGBTs fault diagnosis. Experimental set up is implemented for data acquisition under various faulty and healthy conditions. Recent methods are executed using MATLAB-Simulink and compared using key parameters like average accuracy, fault detection time, implementation efforts, threshold dependency, and detection parameter, resistivity against noise and load dependency.

Transient and Steady-state Tests of the Space Power Research Engine with Resistive and Motor Loads

NASA Technical Reports Server (NTRS)

Rauch, Jeffrey S.; Kankam, M. David

1995-01-01

The NASA Lewis Research Center (LeRC) has been testing free-piston Stirling engine/linear alternators (FPSE/LA) to develop advanced power convertors for space-based electrical power generation. Tests reported herein were performed to evaluate the interaction and transient behavior of FPSE/LA-based power systems with typical user loads. Both resistive and small induction motor loads were tested with the space power research engine (SPRE) power system. Tests showed that the control system could maintain constant long term voltage and stable periodic operation over a large range of engine operating parameters and loads. Modest resistive load changes were shown to cause relatively large voltage and, therefore, piston and displacer amplitude excursions. Starting a typical small induction motor was shown to cause large and, in some cases, deleterious voltage transients. The tests identified the need for more effective controls, if FPSE/LAs are to be used for stand-alone power systems. The tests also generated a large body of transient dynamic data useful for analysis code validation.

Transient and steady-state tests of the space power research engine with resistive and motor loads

NASA Astrophysics Data System (ADS)

Rauch, Jeffrey S.; Kankam, M. David

1995-01-01

The NASA Lewis Research Center (LeRC) has been testing free-piston Stirling engine/linear alternators (FPSE/LA) to develop advanced power convertors for space-based electrical power generation. Tests reported herein were performed to evaluate the interaction and transient behavior of FPSE/LA-based power systems with typical user loads. Both resistive and small induction motor loads were tested with the space power research engine (SPRE) power system. Tests showed that the control system could maintain constant long term voltage and stable periodic operation over a large range of engine operating parameters and loads. Modest resistive load changes were shown to cause relatively large voltage and, therefore, piston and displacer amplitude excursions. Starting a typical small induction motor was shown to cause large and, in some cases, deleterious voltage transients. The tests identified the need for more effective controls, if FPSE/LAs are to be used for stand-alone power systems. The tests also generated a large body of transient dynamic data useful for analysis code validation.

Coplanar UHF RFID tag antenna with U-shaped inductively coupled feed for metallic applications

PubMed Central

Ismail, Alyani; Raja Abdullah, Raja Syamsul Azmir; Saeedi, Tale

2017-01-01

In this paper, we present a novel compact, coplanar, tag antenna design for metallic objects. Electrically small antenna has designed for a UHF RFID (860–960 MHz) based on a proximity-coupled feed through. Furthermore, two symmetrical Via-loaded coplanar grounds fed by a U-shaped inductively coupled feed through an embedded transmission line. This configuration results in an antenna with dimensions of 31 × 19.5 × 3.065 mm3 at 915 MHz, and the total gain for the antenna is 0.12 dBi. The Via-loaded coplanar and U-shaped inductively coupled feeds allow the antenna to provide flexible tuning in terms of antenna impedance. In addition, a figure of merit is applied for the proposed tag antenna, and the results are presented. The read range is measured to be 4.2 m, which is very close to simulated values. This antenna measurement shows very good agreement with simulations. PMID:28570706

Coplanar UHF RFID tag antenna with U-shaped inductively coupled feed for metallic applications.

PubMed

Salman, Karrar Naji; Ismail, Alyani; Raja Abdullah, Raja Syamsul Azmir; Saeedi, Tale

2017-01-01

In this paper, we present a novel compact, coplanar, tag antenna design for metallic objects. Electrically small antenna has designed for a UHF RFID (860-960 MHz) based on a proximity-coupled feed through. Furthermore, two symmetrical Via-loaded coplanar grounds fed by a U-shaped inductively coupled feed through an embedded transmission line. This configuration results in an antenna with dimensions of 31 × 19.5 × 3.065 mm3 at 915 MHz, and the total gain for the antenna is 0.12 dBi. The Via-loaded coplanar and U-shaped inductively coupled feeds allow the antenna to provide flexible tuning in terms of antenna impedance. In addition, a figure of merit is applied for the proposed tag antenna, and the results are presented. The read range is measured to be 4.2 m, which is very close to simulated values. This antenna measurement shows very good agreement with simulations.

Inhibition of p38 MAPK during cellular activation modulate gene expression of head kidney leukocytes isolated from Atlantic salmon (Salmo salar) fed soy bean oil or fish oil based diets.

PubMed

Holen, E; Winterthun, S; Du, Z-Y; Krøvel, A V

2011-01-01

Head kidney leukocytes isolated from Atlantic salmon fed either a diet based on fish oil (FO) or soy bean oil (VO) were used in order to evaluate if different lipid sources could contribute to cellular activation of the salmon innate immune system. A specific inhibitor of p38 MAPK, SB202190, was used to investigate the effect of lipopolysaccharide (LPS) signalling in the head kidney leukocytes. The results show that LPS up regulate IL-1β, TNF-α, Cox2 expression in leukocytes isolated from fish fed either diet. The p38 MAPK inhibitor, SB202190, reduced the LPS induced expression of these genes in both dietary groups. In LPS stimulated leukocytes isolated from VO fed fish, SB202190 showed a clear dose dependent inhibitory effect on IL-1β, TNF-α and Cox2 expression. This effect was also observed for Cox2 in leukocytes isolated from FO fed fish. Furthermore, there was a stronger mean induction of Cox2 in LPS stimulated leucocytes isolated from the VO-group compared to LPS stimulated leukocytes isolated from the FO-group. In both dietary groups, LPS stimulation of salmon head kidney leukocytes increased the induction of CD83, a dendrite cell marker, while the inhibitor reduced CD83 expression in the VO fed fish only. The inhibitor also clearly reduced hsp27 expression in VO fed fish. Indicating a p38 MAPK feedback loop, LPS significantly inhibited the expression of p38MAPK itself in both diets, while SB202190 increased p38MAPK expression especially in the VO diet group. hsp70 expression was not affected by any treatment or feed composition. There were also differences in p38MAPK protein phosphorylation comparing treatment groups but no obvious difference comparing the two dietary groups. The results indicate that dietary fatty acids have the ability to modify signalling through p38 MAPK which may have consequences for the fish's ability to handle infections and stress. Signalling through p38MAPK is ligand dependent and affects gene and protein expression differently