Sample records for dc wiring system

  1. Ripple Reduction Characteristics in the Parallel-Connected DC Power Distribution System Constructed by New Terminals for Wire Communication

    NASA Astrophysics Data System (ADS)

    Katsuki, Akihiko; Matsumoto, Tadashi; Watanabe, Shogo; Fukunaga, Masaichi

    Powering terminal should prevent signal inflow from the communication lines. Powered terminal in most wire communication systems needs to separate ac signals and dc supply power in its input part connected to the communication lines. Our original communication system consists of low-power dc-dc converters. In our system, the direction of dc power is opposite in powering terminal at reception and powered terminal. Therefore, to use the same electronic choke for powering terminal and powered terminal, it is preferable that the electronic choke be bidirectional. So, we have proposed new electronic choke by the use of small inductors and an amplifier. From the viewpoint of power distribution, this system contains a parallel-connected dc power supply. In this paper, voltage-ripple attenuation characteristics at reception are presented on the dc power distribution system using buck-type converters and new electronic chokes. New electronic choke has an ability of good attenuation against signals. Even though switching frequencies are different, no beat is observed in the output dc voltage waveform of powered terminal. New electronic choke effectively removes circulation or interference by the ripple.

  2. dc conductance of molecular wires

    NASA Astrophysics Data System (ADS)

    Prodan, Emil; Car, Roberto

    2007-09-01

    Inspired by the work of Kamenev and Kohn [Phys. Rev. B 63, 155304 (2001)], we present a general discussion of the two-terminal dc conductance of molecular devices within the framework of time dependent current-density functional theory in the linear response regime. We derive a formally exact expression for the adiabatic conductance. For junctions made of long molecular chains that can be either metallic or insulating, we derive the exact asymptotic behavior of the adiabatic conductance as a function of the chain’s length. Our results follow from the analytic structure of the bands of a periodic molecular chain and a compact expression for the Green’s functions. In the case of an insulating chain, not only do we obtain the exponentially decaying factors, but we also obtain the corresponding amplitudes, which depend very sensitively on the electronic properties of the contacts. We illustrate the theory by a numerical study of a simple insulating structure connected to two metallic jellium leads.

  3. A Constant DC-Capacitor Voltage Control Based Strategy for Current Balancer in Single-Phase Three-Wire Distribution Systems

    NASA Astrophysics Data System (ADS)

    Baba, Yusuke; Okamoto, Masayuki; Hiraki, Eiji; Tanaka, Toshihiko; Lee, Seong Ryong

    This paper proposes a strategy based on constant dc-capacitor voltage control for a current balancer in single-phase three-wire distribution systems. The proposed control strategy involves the use of only the constant dc-capacitor voltage control block commonly used in active power conditioners for the calculation of the compensation current. No calculation block is required to obtain the reactive and unbalanced-active components. Thus, we provide the simplest possible control strategy for the current balancer. The basic principle of the proposed control method is discussed in detail and its validity, which is confirmed by a digital computer simulation using PSIM software, is shown. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents with a power factor of unity are obtained on the secondary side of a pole-mounted distribution transformer while unbalanced load current conditions with a lagging power factor are retained.

  4. LANSCE-R WIRE-SCANNER SYSTEM

    SciTech Connect

    Gruchalla, Michael E. [Los Alamos National Laboratory

    2011-01-01

    The National Instruments cRIO platform is used for the new LANSCE-R wire-scanner systems. All wire-scanner electronics are integrated into a single BiRa BiRIO 4U cRIO chassis specifically designed for the cRIO crate and all interface electronics. The BiRIO chassis, actuator and LabVIEW VIs provide a complete wire-scanner system integrated with EPICS. The new wire-scanner chassis includes an 8-slot cRIO crate with Virtex-5 LX 110 FPGA and Power-PC real-time controller, the LANL-developed cRIO 2-axis wire-sensor analog interface module (AFE), NI9222 cRIO 4-channel 16-bit digitizer, cRIO resolver demodulator, cRIO event receiver, front-panel touch panel display, motor driver, and all necessary software, interface wiring, connectors and ancillary components. This wirescanner system provides a complete, turn-key, 2-axis wire-scanner system including 2-channel low-noise sensewire interface with variable DC wire bias and wireintegrity monitor, 16-bit signal digitizers, actuator motor drive and control, actuator position sensing, limit-switch interfaces, event receiver, LabVIEW and EPICS interface, and both remote operation and full stand-alone operation using the touch panel.

  5. Establishment of a Switched-Reluctance Generator-Based Common DC Microgrid System

    Microsoft Academic Search

    Yuan-Chih Chang; Chang-Ming Liaw

    2011-01-01

    This paper presents a dc microgrid including a switched-reluctance generator (SRG) with isolated boost dc-dc converter, a battery energy storage system, and a single-phase three-wire (1P3W) load inverter for generating ac 220\\/110 V 60-Hz outputs. The 400-V dc grid is established by the SRG with dc 48-V output followed by a current-fed push-pull (CFPP) dc-dc converter. The robust commutation and

  6. A Prototype Wire Position Monitoring System

    SciTech Connect

    Wang, Wei

    2010-12-07

    The Wire Position Monitoring System (WPM) will track changes in the transverse position of LCLS Beam Position Monitors (BPMs) to 1{micro}m over several weeks. This position information will be used between applications of beam based alignment to correct for changes in component alignment. The WPM system has several requirements. The sensor range must be large enough so that precision sensor positioning is not required. The resolution needs to be small enough so that the signal can be used to monitor motion to 1{micro}m. The system must be stable enough so that system drift does not mimic motion of the component being monitored. The WPM sensor assembly consists of two parts, the magnetic sensor and an integrated lock-in amplifier. The magnetic sensor picks up a signal from the alternating current in a stretched wire. The voltage v induced in the sensor is proportional to the wire displacement from the center of the sensor. The integrated lock-in amplifier provides a DC output whose magnitude is proportional to the AC signal from the magnetic sensor. The DC output is either read on a digital voltmeter or digitized locally and communicated over a computer interface.

  7. Illumination system for wire bonding inspection

    NASA Astrophysics Data System (ADS)

    Perng, Der-Baau; Chou, Cheng-Chuan; Lee, Shu-Ming

    2007-02-01

    A novel lighting system was devised for 3D defect inspection in the wire bonding process. Gold wires of 20 ?m in diameter were bonded to connect the integrated circuit (IC) chip with the substrate. Bonding wire defects can be classified as 2D type and 3D type. The 2D-type defects include missed, shifted, or shorted wires. These defects can be inspected from a 2D top-view image of the wire. The 3D-type bonding wire defects are sagging wires, and are difficult to inspect from a 2D top-view image. A structured lighting system was designed and developed to facilitate all 2D-type and 3D-type defect inspection. The devised lighting system can be programmed to turn the structured LEDs on or off independently. Experiments show that the devised illumination system is effective for wire bonding inspection and will be valuable for further applications.

  8. Development of a robot car wiring system

    Microsoft Academic Search

    Kyong-mo Koo; Xin Jiang; Kohei Kikuchi; A. Konno; M. Uchiyama

    2008-01-01

    In this paper, the development of a robot car wiring system is addressed. It is designed to be used for automatically assembling wire harness into a car body. This operation is among the most difficult tasks of vehicle assembly and is not yet automated. Based on an analysis of the requirements for a robot car wiring system, we propose a

  9. Ultracapacitors + DC-DC converters in regenerative braking system

    Microsoft Academic Search

    J. W. Dixon; M. E. Ortuzar

    2002-01-01

    An ultracapacitor system for an electric vehicle has been implemented. The device allows higher accelerations and decelerations of the vehicle with minimal loss of energy and minimal degradation of the main battery pack. The system uses a DC-DC power converter, which is connected between the ultracapacitor and the main battery pack. The design has been optimized in weight and size,

  10. Measurements and simulations of the ionic wind produced by a DC corona discharge between cylindrical wires

    Microsoft Academic Search

    P. Bérard; D. A. Lacoste; C. O. Laux

    A parametric study of a system comprised of two parallel wires creating ionic wind in atmospheric air is presented. The experimental setup intends to see the effect of the gap between the electrodes, the wire diameters, the material and the polarity of the electrodes, the voltage and the current. The current is steady-state for the positive discharge and contains Trichel

  11. DC Power Distribution Systems 

    E-print Network

    Savage, P.

    2012-01-01

    Low capital cost and ample low-cost natural gas supplies will make natural gas-fired combustion turbine systems the power generation technology of choice over the next decade. Against the background of earlier use by electric utilities, this paper...

  12. DC-DC converter design for battery-operated systems

    Microsoft Academic Search

    B. Arbetter; R. Erickson; D. Maksimovic

    1995-01-01

    This paper describes performance, design and optimization of DC-DC converters for energy limited, battery operated systems. Variable-frequency operation is used to achieve voltage regulation and high efficiency for an extremely wide range of load currents. An experimental 15 W, 3.3 V buck converter has been constructed to demonstrate design and optimization techniques. The converter employs synchronous rectification to reduce conduction

  13. DC Magnetics Measurement System Design

    NASA Technical Reports Server (NTRS)

    Mastny, Timothy

    2012-01-01

    This report will detail the updates to the magnetics measurement system design and testing procedures that are required for performing static (DC) magnetics testing of future flight hardware. An older magnetics testing system had to be integrated with new procedures and hardware to meet the demands of future testing programs and accommodate an upcoming magnetics tests. The next test will be for the Geostationary Operational Environmental Satellite R-Series (GOES-R), which will verify that the SAFT Battery component meets its specifications for magnetic cleanliness. The satellite is scheduled to launch in 2015 with magnetics testing to be completed on the battery in November 2012.

  14. Systems Analysis Teaching: The Kengor Wire Company

    ERIC Educational Resources Information Center

    Kennedy, W. J., Jr.; Derrick, L. R.

    1976-01-01

    Describes a group of systems analysis courses which utilizes a computer model of a company which makes house wire to provide a realistic representation of the complexities involved in industrial management. (CP)

  15. Component Minimized AC–DC–AC Single-Phase to Three-Phase Four-Wire Converters

    Microsoft Academic Search

    Euzeli Cipriano dos Santos; Cursino Brandão Jacobina; Gregory Arthur de Almeida Carlos; Isaac Soares de Freitas

    2011-01-01

    This paper proposes two sets of topologies for single-phase to three-phase four-wire ac-dc-ac power conversion. All proposed configurations are characterized by reduction in the number of switches. The first set includes five configurations using ten power switches, while the second one includes six configu- rations using eight power switches. Such configurations are con- ceived for supplying three-phase four-wire loads and

  16. Inspection of anode and field wires for the COMPASS drift chamber, DC5, with Environmental Scanning Electron Microscope

    NASA Astrophysics Data System (ADS)

    Cyuzuzo, Sonia

    2014-09-01

    The COMPASS experiment at CERN uses a secondary pion beam from the Super Proton Synchrotron (SPS) at CERN to explore the spin structure of nucleons. A new drift chamber, DC5, will be integrated into the COMPASS spectrometer to replace an aging straw tube detector. DC5 will detect muon pairs from Drell-Yan scattering of a pion-beam off a transversely polarized proton target. This data will be used to determine the correlation between transverse proton spin and the intrinsic transverse momentum of up-quarks inside the proton, the Sivers effect. DC5 is a large area planar drift chamber with 8 layers of anode-frames made of G10 fiberglass-epoxy. The G10 frames support printed circuit boards for soldering 20 ?m diameter anode and 100 ?m diameter field wires. The anode planes are sandwiched by 13 graphite coated Mylar cathode planes. To ensure a well-functioning of DC5, the wires were carefully tested. An optical inspection and a spectral analysis was performed with an Environmental Scanning Electron Microscope (ESEM) to verify the composition and dimensions and the integrity of the gold plating on the surface of these wires. The spectra of the wires were studied at 10 and 30 keV. The COMPASS experiment at CERN uses a secondary pion beam from the Super Proton Synchrotron (SPS) at CERN to explore the spin structure of nucleons. A new drift chamber, DC5, will be integrated into the COMPASS spectrometer to replace an aging straw tube detector. DC5 will detect muon pairs from Drell-Yan scattering of a pion-beam off a transversely polarized proton target. This data will be used to determine the correlation between transverse proton spin and the intrinsic transverse momentum of up-quarks inside the proton, the Sivers effect. DC5 is a large area planar drift chamber with 8 layers of anode-frames made of G10 fiberglass-epoxy. The G10 frames support printed circuit boards for soldering 20 ?m diameter anode and 100 ?m diameter field wires. The anode planes are sandwiched by 13 graphite coated Mylar cathode planes. To ensure a well-functioning of DC5, the wires were carefully tested. An optical inspection and a spectral analysis was performed with an Environmental Scanning Electron Microscope (ESEM) to verify the composition and dimensions and the integrity of the gold plating on the surface of these wires. The spectra of the wires were studied at 10 and 30 keV. Acknowledging NSF and UIUC.

  17. A BiDirectional DC\\/DC Converter for an Energy Storage System

    Microsoft Academic Search

    Shigenori Inoue; Hirofumi Akagi

    2007-01-01

    This paper addresses a bi-directional dc\\/dc converter suitable for an energy storage system with an additional function of galvanic isolation. An energy storage device such as an electric double layer capacitor is directly connected to one of the dc buses of the dc\\/dc converter without any chopper circuit. Nevertheless, the dc\\/dc converter can continue operating when the voltage across the

  18. A FLYING WIRE SYSTEM IN THE AGS.

    SciTech Connect

    HUANG,H.; BUXTON,W.; MAHLER,G.; MARUSIC,A.; ROSER,T.; SMITH,G.; SYPHERS,M.; WILLIAMS,N.; WITKOVER,R.

    1999-03-29

    As the AGS prepares to serve as the injector for RHIC, monitoring and control of the beam transverse emittance become a major and important topic. Before the installation of the flying wire system, the emittance was measured with ionization profile monitors in the AGS, which require correction for space charge effects. It is desirable to have a second means of measuring profile that is less depend on intensity. A flying wire system has been installed in the AGS recently to perform this task. This paper discusses the hardware and software setup and the capabilities of the system.

  19. USAF/WL robust 300 C wire insulation system program status

    NASA Technical Reports Server (NTRS)

    Wong, Wing

    1995-01-01

    The objective of this program is to identify, develop, and demonstrate an optimum wire insulation system capable of continuous operation at 300 C which possesses a combination of superior electrical (AC or DC), mechanical, and physical properties over Kapton derived insulations described in MIL-W-81381 and those hybrid materials commonly known as TKT constructions.

  20. Interleaved Bidirectional DC-DC Converter for Automotive Electric Systems

    Microsoft Academic Search

    Dong-Hyun Ha; Nam-Ju Park; Kui-Jun Lee; Dong-Gyu Lee; Dong-Seok Hyun

    2008-01-01

    In this paper, interleaved bidirectional DC-DC converter with ZVT cell using a single resonant inductor in continuous conduction mode is proposed. The proposed interleaved bidirectional DC-DC converter has advantages such as a simple circuit, ZVS during wide load range and minimization of current injection effect by using dual current injection time. Also, it is possible to reduce diode drop voltage

  1. 1Wire based data acquisition system

    Microsoft Academic Search

    Georgi Georgiev

    2009-01-01

    An implementation of a 1-Wire network (MicroLan) for temperature monitoring is presented. The observations of the author regarding important parameters of the network, such as maximum length and maximum number of devices, are stated. The architecture and algorithm of the data acquisition system are presented. Specific attention is given to techniques for protecting the software implementation against reverse engineering and

  2. Multiport DC\\/DC Converter for Stand-alone Photovoltaic Lighting System with Battery Storage

    Microsoft Academic Search

    Shengyong Liu; Xing Zhang; Haibin Guo; Jun Xie

    2010-01-01

    Photovoltaic energy has nowadays an increased importance in electrical power applications. However, the output power provided via the photovoltaic conversion process depends on solar irradiation and temperature. Therefore a multiple-input DC\\/DC converter is proposed for stand-alone photovoltaic lighting system with battery storage in this paper. Compared with the traditional stand-alone photovoltaic system, which merely use one muti-input biderictional DC\\/DC converter

  3. Control of a modular multilevel cascade BTB system using bidirectional isolated DC\\/DC converters

    Microsoft Academic Search

    Hirofumi Akagi; Ryohei Kitada

    2010-01-01

    This paper discusses the 6.6-kV BTB (back-to-back) system combining bidirectional isolated dc\\/dc converters with modular multilevel cascade PWM converters. The system consists of multiple converter cells connected in cascade per phase at both front ends. Each converter cell consists of a bidirectional isolated high-frequency dc\\/dc converter and two voltage-source H-bridge PWM converters. Extremely low voltage steps bring a significant reduction

  4. In-Situ Wire Damage Detection System

    NASA Technical Reports Server (NTRS)

    Williams, Martha K. (Inventor); Roberson, Luke B. (Inventor); Tate, Lanetra C. (Inventor); Smith, Trent M. (Inventor); Gibson, Tracy L. (Inventor); Jolley, Scott T. (Inventor); Medelius, Pedro J. (Inventor)

    2014-01-01

    An in-situ system for detecting damage in an electrically conductive wire. The system includes a substrate at least partially covered by a layer of electrically conductive material forming a continuous or non-continuous electrically conductive layer connected to an electrical signal generator adapted to delivering electrical signals to the electrically conductive layer. Data is received and processed to identify damage to the substrate or electrically conductive layer. The electrically conductive material may include metalized carbon fibers, a thin metal coating, a conductive polymer, carbon nanotubes, metal nanoparticles or a combination thereof.

  5. A Microgrid-based Telecom Power System using Modular Multiple-Input DC-DC Converters

    Microsoft Academic Search

    Alexis Kwasinski; P. T. Krein

    2005-01-01

    This paper presents a telecom power plant that uses local distributed generation resources and the utility grid as power inputs to the system. The microsources are connected to a high voltage main dc bus using multiple-input dc-dc converters. Additional converters are used in the secondary power distribution frames. The proposed architecture reduces the energy storage requirements and is more reliable

  6. Rule-Based Expert System for Designing DC-DC Converters

    Microsoft Academic Search

    Seok Min Yoon; Jong Tae Kim

    2006-01-01

    \\u000a The design of DC-DC converters mainly relies on the experience of the designer who is usually aided by simulation programs\\u000a such as SPICE. Since it is very difficult to design highly efficient and reliable converters, even for the experienced designer,\\u000a we developed a design automation tool for isolated DC-DC converters based on a rule-based expert system. We define a set

  7. Development of a 55 kW 3X DC-DC Converter for HEV Systems

    E-print Network

    Tolbert, Leon M.

    Development of a 55 kW 3X DC-DC Converter for HEV Systems Wei Qian and Fang Z. Peng Department, 37996 Abstract--The design of a 55 kW 3X dc-dc converter is presented for hybrid electric vehicle (HEV; voltage dividers. I. INTRODUCTION A typical Plug-in HEV drive train consists of a battery, a power

  8. Fault diagnostics in power electronics-based brake-by-wire systems

    E-print Network

    Mi, Chunting "Chris"

    and validated using data from both a simulation and a laboratory set-up with a 1=3 hp d.c. motor and a d.1243/09544070JAUTO385 Abstract: A d.c.-motor-based brake-by-wire system is studied for the purpose of fault diagnostics of the power electronic switches. The voltage and current generated in the switching circuit under

  9. High-frequency ultrasonic wire bonding systems

    PubMed

    Tsujino; Yoshihara; Sano; Ihara

    2000-03-01

    The vibration characteristics of longitudinal-complex transverse vibration systems with multiple resonance frequencies of 350-980 kHz for ultrasonic wire bonding of IC, LSI or electronic devices were studied. The complex vibration systems can be applied for direct welding of semiconductor tips (face-down bonding, flip-chip bonding) and packaging of electronic devices. A longitudinal-complex transverse vibration bonding system consists of a complex transverse vibration rod, two driving longitudinal transducers 7.0 mm in diameter and a transverse vibration welding tip. The vibration distributions along ceramic and stainless-steel welding tips were measured at up to 980 kHz. A high-frequency vibration system with a height of 20.7 mm and a weight of less than 15 g was obtained. PMID:10829633

  10. CNC Automatic Programming System for Wire-EDM

    Microsoft Academic Search

    Tawfik T. El-midany; Ahmed Elkeran; H. T. Radwan

    1999-01-01

    \\u000a This paper introduces a developed CAM system for wire-EDM to automatically select the sequencing of the wire path considering\\u000a fixation stability. The system creates technological aspects based on geometry features. Many of the wire cutting techniques\\u000a such as trim cut, correction, taper angle, threading & breaking points, and the standard radius are automatically added. For\\u000a small area of polygons No-Core

  11. Laser measuring system for wire-wrapped frame assemblies

    Microsoft Academic Search

    J. G. Etzel; J. A. Munford

    1979-01-01

    The laser measuring system is designed to automatically measure and record the distances between small diameter wires on a wire wrapped grid frame assembly to an accuracy of 0.00635 mm (0.00025 in.). The system utilizes a helium-neon gas laser beam as the measuring instrument with a remote interferometer and retroreflector, a light source and photodetector to detect the wire positions,

  12. A simple three-channel dc SQUID system using time domain multiplexing M. Mck and M. Korn

    E-print Network

    Le Roy, Robert J.

    A simple three-channel dc SQUID system using time domain multiplexing M. Mück and M. Korn Justus) Conventional multichannel superconducting quantum interference device (SQUID) systems require a SQUID read-out circuit for each channel, as well as many wires connecting each individual SQUID and feedback coil

  13. Design of automotive X-by-Wire systems Cdric Wilwert

    E-print Network

    Paris-Sud XI, Université de

    Design of automotive X-by-Wire systems Cédric Wilwert PSA Peugeot - Citroën 92000 La Garenne Phone : +33 3 83 58 17 62 simonot@loria.fr CONTENTS Design of automotive X-by-Wire systems ................................................................................................................................ 9 3.2 Main time-triggered protocols for automotive industry

  14. Multiterminal DC transmission system based on modular multilevel converter

    Microsoft Academic Search

    Grain P Adam; Olimpo Anaya-Lara; Graeme Burt

    2009-01-01

    A multi-terminal DC (MTDC) transmission system based on an innovative modular multilevel converter (MMC) is presented as a feasible approach to address the concerns regarding reliability and fault ride through capability of multi-terminal dc systems. Furthermore, MTDC using MMC may reduce construction costs and power losses in the converter stations. To demonstrate control flexibility, improved reliability and DC fault ride

  15. System and method for evaluating a wire conductor

    DOEpatents

    Panozzo, Edward; Parish, Harold

    2013-10-22

    A method of evaluating an electrically conductive wire segment having an insulated intermediate portion and non-insulated ends includes passing the insulated portion of the wire segment through an electrically conductive brush. According to the method, an electrical potential is established on the brush by a power source. The method also includes determining a value of electrical current that is conducted through the wire segment by the brush when the potential is established on the brush. The method additionally includes comparing the value of electrical current conducted through the wire segment with a predetermined current value to thereby evaluate the wire segment. A system for evaluating an electrically conductive wire segment is also disclosed.

  16. A DC-DC Converter-Based PEM Fuel Cell System Emulator

    E-print Network

    Boyer, Edmond

    A DC-DC Converter-Based PEM Fuel Cell System Emulator Daoud Rezzak, Farid Khoucha, Mohamed Benbouzid, Abdelaziz Kheloui and Abdeslam Mamoune Abstract--The Proton Exchange Membrane Fuel Cell (PEMFC power supplies. Fuel cell systems are characterized by high costs and complex auxiliary devices

  17. New Solar Cell Power Supply System Using a Boost Type Bidirectinal DC-DC Converter

    Microsoft Academic Search

    Hirofumi Matsuo; Fujio Kurokawa

    1984-01-01

    A new solar cell power supply system is presented, in which the boost type bidirectional dc-dc converter and the simple control circuit with a small monitor solar cell are employed to track the maximum power point of the solar array. It is confirmed by the experiment that the new system has sufficiently precise tracking operation performance and satisfactorily high power

  18. Research of substation ground wire monitoring system based on WLAN

    Microsoft Academic Search

    Wanzhi Chen; Jianhui Liu

    2009-01-01

    To implement substation ground wire of online monitoring application solutions using integration technology of wireless local area network and embedded systems, share the information of ground wire installed, increase production installed office efficiency, improve the level of substation ground management. To ensure safety in production in a certain role of supervision, has certain economic benefits and social benefits. Secondly, for

  19. Broken Wire Tests on a Model Transmission Line System

    Microsoft Academic Search

    John Mozer; William Wood; John Hribar

    1981-01-01

    This paper presents the results of broken wire tests which were conducted on a model transmission line system as part of a research project funded by the Electric Power Research Institute. The purpose of these tests was to provide static and dynamic data on the longitudinal loadings and structure responses, which are produced by broken conductors, broken shield wires, or

  20. Modeling and System Identification for a DC Servo

    E-print Network

    to use the DC Servo motor SRV02ET that is provided by Quanser. The motor has a transfer function that we. · 1 SRV 02ET servo DC motor. · 1 Analog sensor cable. · 1 To load Cable. · 1 To A/D Cable. · 1 From DModeling and System Identification for a DC Servo Nicanor Quijano and Kevin M. Passino The Ohio

  1. KIM-1 interface adapter to 3-wire teletype systems

    NASA Technical Reports Server (NTRS)

    Burhans, R. W.

    1976-01-01

    The KIM-1 circuit designed for use with a full duplex isolated 4 terminal system is described. Operation of the circuit with a 3 wire system in conjunction with a single +5v supply interface is discussed.

  2. 14 CFR 121.1111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2014-01-01 false Electrical wiring interconnection systems...Continued Airworthiness and Safety Improvements § 121.1111 Electrical wiring interconnection systems...inspections and procedures for electrical wiring interconnection...

  3. 14 CFR 121.1111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 2012-01-01 false Electrical wiring interconnection systems...Continued Airworthiness and Safety Improvements § 121.1111 Electrical wiring interconnection systems...inspections and procedures for electrical wiring interconnection...

  4. 14 CFR 121.1111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 2013-01-01 false Electrical wiring interconnection systems...Continued Airworthiness and Safety Improvements § 121.1111 Electrical wiring interconnection systems...inspections and procedures for electrical wiring interconnection...

  5. 14 CFR 121.1111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2010-01-01 false Electrical wiring interconnection systems...Continued Airworthiness and Safety Improvements § 121.1111 Electrical wiring interconnection systems...inspections and procedures for electrical wiring interconnection...

  6. 14 CFR 121.1111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2011-01-01 false Electrical wiring interconnection systems...Continued Airworthiness and Safety Improvements § 121.1111 Electrical wiring interconnection systems...inspections and procedures for electrical wiring interconnection...

  7. Novel solar cell power supply system using the multiple-input DC-DC converter

    Microsoft Academic Search

    Hirohmi Matsuo; Kimiyoshi Kobayashi; Yutaka Sekine; Matsuyoshi Asano; Lin Wenzhong

    1998-01-01

    Recently, clean electric power generation systems have attracted a great deal of social attention to exploit clean energy resources such as solar arrays, wind generators, fuel cells, etc. In this case, the multiple-input DC-DC power converter is useful to combine the several input power sources and to supply the regulated output voltage for the load. The novel solar cell power

  8. Beam Position and Phase Monitor - Wire Mapping System

    SciTech Connect

    Watkins, Heath A [Los Alamos National Laboratory; Shurter, Robert B. [Los Alamos National Laboratory; Gilpatrick, John D. [Los Alamos National Laboratory; Kutac, Vincent G. [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory

    2012-04-10

    The Los Alamos Neutron Science Center (LANSCE) deploys many cylindrical beam position and phase monitors (BPPM) throughout the linac to measure the beam central position, phase and bunched-beam current. Each monitor is calibrated and qualified prior to installation to insure it meets LANSCE requirements. The BPPM wire mapping system is used to map the BPPM electrode offset, sensitivity and higher order coefficients. This system uses a three-axis motion table to position the wire antenna structure within the cavity, simulating the beam excitation of a BPPM at a fundamental frequency of 201.25 MHz. RF signal strength is measured and recorded for the four electrodes as the antenna position is updated. An effort is underway to extend the systems service to the LANSCE facility by replacing obsolete electronic hardware and taking advantage of software enhancements. This paper describes the upgraded wire positioning system's new hardware and software capabilities including its revised antenna structure, motion control interface, RF measurement equipment and Labview software upgrades. The main purpose of the wire mapping system at LANSCE is to characterize the amplitude response versus beam central position of BPPMs before they are installed in the beam line. The wire mapping system is able to simulate a beam using a thin wire and measure the signal response as the wire position is varied within the BPPM aperture.

  9. Comparison of solar panel cooling system by using dc brushless fan and dc water

    NASA Astrophysics Data System (ADS)

    Irwan, Y. M.; Leow, W. Z.; Irwanto, M.; M, Fareq; Hassan, S. I. S.; Safwati, I.; Amelia, A. R.

    2015-06-01

    The purpose of this article is to discuss comparison of solar panel cooling system by using DC brushless fan and DC water pump. Solar photovoltaic (PV) power generation is an interesting technique to reduce non-renewable energy consumption and as a renewable energy. The temperature of PV modules increases when it absorbs solar radiation, causing a decrease in efficiency. A solar cooling system is design, construct and experimentally researched within this work. To make an effort to cool the PV module, Direct Current (DC) brushless fan and DC water pump with inlet/outlet manifold are designed for constant air movement and water flow circulation at the back side and front side of PV module representatively. Temperature sensors were installed on the PV module to detect temperature of PV. PIC microcontroller was used to control the DC brushless fan and water pump for switch ON or OFF depend on the temperature of PV module automatically. The performance with and without cooling system are shown in this experiment. The PV module with DC water pump cooling system increase 3.52%, 36.27%, 38.98%in term of output voltage, output current, output power respectively. It decrease 6.36 °C compare than to PV module without DC water pump cooling system. While DC brushless fan cooling system increase 3.47%, 29.55%, 32.23%in term of output voltage, output current, and output power respectively. It decrease 6.1 °C compare than to PV module without DC brushless fan cooling system. The efficiency of PV module with cooling system was increasing compared to PV module without cooling system; this is because the ambient temperature dropped significantly. The higher efficiency of PV cell, the payback period of the system can be shorted and the lifespan of PV module can also be longer.

  10. DC Self Bias Trends in Dual Frequency PECVD Deposition Systems

    NASA Astrophysics Data System (ADS)

    Keil, D. L.; Augustyniak, E.; Leeser, C.; Galli, F.

    2011-10-01

    Capacitively coupled plasma (CCP) etch systems commonly report the DC auto or self bias developed as a consequence of capacitively coupling RF to the plasma. Frequently, these systems employ wafer pedestals comprised of electrostatic chucks which must monitor the self bias as part of their normal operation. DC self bias is often found to correlate with various etch process behaviors or system states. It is less common, however, to find CCP deposition systems that report DC self bias. This work reports results of a study of DC self bias trends due to chamber pressure, chamber conditioning and aging, and changes in wafer pedestal hardware. In particular, chamber film accumulation is found to correlate to certain DC bias trends. The applicability of these results for process tracking and system monitoring is discussed. Additionally, the DC self bias response to deliberate perturbations to the RF system are examined. These perturbations include those not normally encountered during commercial deposition such as `bleeding' current to ground.

  11. Flip chip interconnect systems using wire stud bumps and lead free solder

    Microsoft Academic Search

    Satoru Zama; Daniel F. Baldwin; Toshiya Hikami; Hideaki Murata

    2000-01-01

    This research focuses on flip chip interconnect systems consisting of wire stud bumps and solder alloy. Conventional gold (Au) wire stud bumps and new copper (Cu) wire stud bumps were formed on the chip by wire bumping. Cu wire studs were bumped by controlling the ramp of ultrasonic power to eliminate the occurrence of under-pad chip cracks which tend to

  12. Flip chip interconnect systems using copper wire stud bump and lead free solder

    Microsoft Academic Search

    Satoru Zama; Daniel F. Baldwin; Toshiya Hikami; Hideaki Murata

    2001-01-01

    This research focuses on flip chip interconnect systems consisting of wire stud bumps and solder alloy interconnects. Conventional gold (Au) wire stud bumps and new copper (Cu) wire stud bumps were formed on the chip by wire stud bumping. Cu wire studs were bumped by controlling the ramp rate of ultrasonic power to eliminate the occurrence of under-pad chip cracks

  13. An Isolated Bidirectional DC-DC Soft Switching Converter for Super Capacitor Based Energy Storage Systems

    Microsoft Academic Search

    Eiji Hiraki; Koji Yamamoto; T. Mishima

    2007-01-01

    In recent years, power electronic energy storage systems using super capacitor bank have been widely studied and developed for the electronic vehicles. In this paper, a full-bridge\\/centertapped push-pull circuit with active clamp-based soft switching bidirectional DC-DC converter and its control method are presented and discussed. From the results of basic experimental demonstration, the proposed system is able to perform adequate

  14. A push-pull converter based bidirectional DC-DC interface for energy storage systems

    Microsoft Academic Search

    Eiji Hiraki; Kazumasa Hirao; Toshihiko Tanaka; Tomokazu Mishima

    2009-01-01

    In recent years, power electronic energy storage systems using super capacitor bank have been widely studied and developed for the electronic vehicles. In this paper, a full-bridge\\/centertapped push-pull circuit with active clamp-based soft switching bidirectional DC-DC converter and its control method are presented and discussed. From the results of basic experimental demonstration, the proposed system is able to perform adequate

  15. SNS LINAC Wire Scanner System : Signal Levels and Accuracy.

    SciTech Connect

    Plum, M. A. (Michael A.); Christensen, W. (Wynn); Myer, R. E. (Ross E.); Rose, C. R. (Chris R.)

    2002-01-01

    The linac wire scanner system for the Spallation Neutron Source (SNS) at Oak Ridge, TN, USA, calls for 5 units in the medium energy beam transport (MEBT), 5 in the drift tube linac (DTL), and 10 in the coupled cavity linac (CCL). In this paper we present expected signal levels and an analysis of the error in the beam size measurement as functions of wire position and electrical signal errors.

  16. Automobile Brake-by-Wire Control System Design and Analysis

    Microsoft Academic Search

    Weidong Xiang; Paul C. Richardson; Chenming Zhao; Syed Mohammad

    2008-01-01

    The automobile brake-by-wire (BBW) system, which is also called the electromechanical brake system, has become a promising vehicle braking control scheme that enables many new driver interfaces and enhanced performances without a mechanical or hydraulic backup. In this paper, we survey BBW control systems with focuses on fault tolerance design and vehicle braking control schemes. At first, the system architecture

  17. Applying laminated busbars to enhance DC power distribution systems

    Microsoft Academic Search

    M. Stibgen

    2004-01-01

    The intent of this paper will be an overview of how to design and implement laminated busbars into DC power distribution systems. It will include; electrical, physical and thermal characteristics obtained by utilizing a laminated busbar for DC power distribution. The power density of today's technology requires the power distribution system to play an active role in compacting size while

  18. Ferrite insertion at Recycler Flying Wire System

    SciTech Connect

    K.Y. Ng

    2004-02-27

    Ferrite rods are installed inside the flying-wire cavity of the Recycler Ring and at entrance and exit beam pipes in order to absorb high-frequency electromagnetic waves excited by the beam. However, these rods may also deteriorate the vacuum pressure of the ring. An investigation is made to analyze the necessity of the ferrite rods at the entrance and exit beam pipes.

  19. Novel Solar-Cell Power Supply System Using a Multiple-Input DC–DC Converter

    Microsoft Academic Search

    Kimiyoshi Kobayashi; Hirofumi Matsuo; Yutaka Sekine

    2006-01-01

    Recently, the clean electric power generation systems have attracted a great deal of social attention to exploit the clean-energy resources such as solar arrays, wind generators, fuel cells, and so forth. In this case, a multiple-input dc–dc converter is useful to combine the several input power sources and to supply the regulated output voltage for the load from the power

  20. 3X DC-DC Multiplier/Divider for HEV Systems Wei Qian, Fang Z. Peng, Miaosen Shen

    E-print Network

    Tolbert, Leon M.

    3X DC-DC Multiplier/Divider for HEV Systems Wei Qian, Fang Z. Peng, Miaosen Shen Michigan State bus for hybrid electric vehicle (HEV) traction drives. Compared with traditional multi-level dc Vehicle (HEV) systems. Typical HEV drive train consists of a battery, power converter, and a traction

  1. Operational environments for electrical power wiring on NASA space systems

    NASA Technical Reports Server (NTRS)

    Stavnes, Mark W.; Hammoud, Ahmad N.; Bercaw, Robert W.

    1994-01-01

    Electrical wiring systems are used extensively on NASA space systems for power management and distribution, control and command, and data transmission. The reliability of these systems when exposed to the harsh environments of space is very critical to mission success and crew safety. Failures have been reported both on the ground and in flight due to arc tracking in the wiring harnesses, made possible by insulation degradation. This report was written as part of a NASA Office of Safety and Mission Assurance (Code Q) program to identify and characterize wiring systems in terms of their potential use in aerospace vehicles. The goal of the program is to provide the information and guidance needed to develop and qualify reliable, safe, lightweight wiring systems, which are resistant to arc tracking and suitable for use in space power applications. This report identifies the environments in which NASA spacecraft will operate, and determines the specific NASA testing requirements. A summary of related test programs is also given in this report. This data will be valuable to spacecraft designers in determining the best wiring constructions for the various NASA applications.

  2. Wire constant tension fuzzy control for WEDG system

    Microsoft Academic Search

    Fang Ji; Lianxin Zhang; Zhiqun Wu; Guangmin Liu; Yongbin Zhang

    2010-01-01

    WEDG (Wire Electrical Discharge Grinding) technology promoted the quality and efficiency of micro electrode manufacturing on position successfully, and realized the practical use of MEDM in engineering fields. And then a new type WEDG system is designed, the working principle of this WEDG system is analyzed and the control model of the WEDG system is presented in this paper. On

  3. Automatic physical design of large wire-wrap digital systems

    SciTech Connect

    Widdoes, L.C. Jr.

    1980-12-01

    A system is described which automatically performs the detailed physical design of a wire-wrap digital system, given a completed logical design, chip placement, and user-specification of the particular component technology and wire-wrap package to be used. The system approximately optimizes measures of the manufacturability, reliability, and performance level of the physical design, as defined by parameters provided by the user. The system's models of the wire-wrap environment and component technologies are surveyed, and its major algorithms for physical design are discussed in detail. These models and algorithms are novel in that they are detailed enough to allow the complete high-quality physical design of large, high-performance central-processing units. Furthermore, they are designed to be easily adapted by the user for specific design efforts.

  4. Automatic physical design of large wire-wrap digital systems

    NASA Astrophysics Data System (ADS)

    Widdoes, L. C., Jr.

    1980-12-01

    A system is described which automatically performs the detailed physical design of a wire wrap digital system, given a completed logical design, chip placement, and user specification of the particular component technology and wire wrap package to be used. The system approximately optimizes measures of the manufacturability, reliability, and performance level of the physical design, as defined by parameters provided by the user. The system's models of the wire wrap environment and component technologies are surveyed, and its major algorithms for physical design are discussed in detail. These models and algorithms are novel in that they are detailed enough to allow the complete high quality physical design of large, high performance central processing units. Furthermore, they are designed to be easily adapted by the user for specific design efforts.

  5. Control and Design of a Modular Multilevel Cascade BTB System Using Bidirectional Isolated DC\\/DC Converters

    Microsoft Academic Search

    Hirofumi Akagi; Ryohei Kitada

    2011-01-01

    This paper discusses the control and design of the 6.6-kV back-to-back (BTB) system combining bidirectional iso- lated dc\\/dc converters and modular multilevel cascade pulsewidth modulation (PWM) converters. The system consists of multiple converter cells connected in cascade per phase at both front ends. Each converter cell consists of a bidirectional isolated medium- frequency dc\\/dc converter and two voltage-source H-bridge (single-

  6. DC isolation and protection system and circuit

    NASA Technical Reports Server (NTRS)

    Wagner, Charles A. (Inventor); Kellogg, Gary V. (Inventor)

    1991-01-01

    A precision analog electronic circuit that is capable of sending accurate signals to an external device that has hostile electric characteristics, including the presence of very large common mode voltages. The circuit is also capable of surviving applications of normal mode overvoltages of up to 120 VAC/VDC for unlimited periods of time without damage or degradation. First, the circuit isolates the DC signal output from the computer. Means are then provided for amplifying the isolated DC signal. Further means are provided for stabilizing and protecting the isolating and amplifying means, and the isolated and amplified DC signal which is output to the external device, against overvoltages and overcurrents.

  7. Wired.

    ERIC Educational Resources Information Center

    Conklin, Aaron R.

    1998-01-01

    Discusses technology's impact on scoreboard design: the development of the light-emitting diode (LED) display. How the LED system works is explained, as are the advantages and disadvantages of LED compared with incandescent lamp boards. Final comments address deciding on materials for scoreboard casings. (GR)

  8. CSMP (Continuous System Modeling Program) modeling of brushless DC motors

    Microsoft Academic Search

    S. M. Thomas

    1984-01-01

    Recent improvements in rare earth magnets have made it possible to construct strong, lightweight, high horsepower DC motors. This has occasioned a reassessment of electromechanical actuators as alternatives to comparable pneumatic and hydraulic systems for use in flight control actuators for tactical missiles. This thesis develops a low-order mathematical model for the simulation and analysis of brushless DC motor performance.

  9. Risk management in fly-by-wire systems

    NASA Technical Reports Server (NTRS)

    Knoll, Karyn T.

    1993-01-01

    A general description of various types of fly-by-wire systems is provided. The risks inherent in digital flight control systems, like those used in the Space Shuttle, are identified. The results of a literature survey examining risk management methods in use throughout the aerospace industry are presented. The applicability of these methods to the Space Shuttle program is discussed.

  10. A High Frequency-Link Bidirectional DC-DC Converter for Super Capacitor-Based Automotive Auxiliary Electric Power Systems

    Microsoft Academic Search

    Tomokazu Mishima; Eiji Hiraki; Mutsuo Nakaoka

    2009-01-01

    This paper presents a bidirectional DC-DC converter suitable for low-voltage super capacitor-based electric energy storage systems. The DC-DC converter presented here consists of a full-bridge circuit and a current-fed push-pull circuit with a high frequency (HF) transformer-link. In order to reduce the device-conduction losses due to the large current of the super capacitor as well as unnecessary ringing, synchronous rectification

  11. An Environmental Monitoring System with Integrated Wired and Wireless Sensors

    E-print Network

    Huang, Yan

    An Environmental Monitoring System with Integrated Wired and Wireless Sensors Jue Yang, Chengyang Zhang, Xinrong Li, Yan Huang, Shengli Fu, and Miguel Acevedo University of North Texas, Denton, Texas 76207, USA {jy0074,cz0022,xinrong,huangyan,fu,acevedo}@unt.edu Abstract. Wireless sensor networks (WSN

  12. NASA/BAE SYSTEMS SpaceWire Effort

    NASA Technical Reports Server (NTRS)

    Rakow, Glenn Parker; Schnurr, Richard G.; Kapcio, Paul

    2003-01-01

    This paper discusses the state of the NASA and BAE SYSTEMS developments of SpaceWire. NASA has developed intellectual property that implements SpaceWire in Register Transfer Level (RTL) VHDL for a SpaceWire link and router. This design has been extensively verified using directed tests from the SpaceWire Standard and design specification, as well as being randomly tested to flush out hard to find bugs in the code. The high level features of the design will be discussed, including the support for multiple time code masters, which will be useful for the James Webb Space Telescope electrical architecture. This design is now ready to be targeted to FPGA's and ASICs. Target utilization and performance information will be presented for Spaceflight worthy FPGA's and a discussion of the ASIC implementations will be addressed. In particular, the BAE SYSTEMS ASIC will be highlighted which will be implemented on their .25micron rad-hard line. The chip will implement a 4-port router with the ability to tie chips together to make larger routers without external glue logic. This part will have integrated LVDS drivers/receivers, include a PLL and include skew control logic. It will be targeted to run at greater than 300 MHz and include the implementation for the proposed SpaceWire transport layer. The need to provide a reliable transport mechanism for SpaceWire has been identified by both NASA And ESA, who are attempting to define a transport layer standard that utilizes a low overhead, low latency connection oriented approach that works end-to-end. This layer needs to be implemented in hardware to prevent bottlenecks.

  13. New DC–DC Converter for Energy Storage System Interfacing in Fuel Cell Hybrid Electric Vehicles

    Microsoft Academic Search

    Mario Marchesoni; Camillo Vacca

    2007-01-01

    The use of energy storage devices such as batteries or supercapacitors is almost mandatory in fuel cell hybrid electric vehicles, in order to guarantee load leveling, assuring braking energy recovery and good performances in transient operations. To this end, converters with bidirectional power flows are needed to connect the accumulators to the dc-link of the motor drive system. In this

  14. Channel Characterization and EMC Assessment of a PLC System for Spacecraft DC Differential Power Buses

    Microsoft Academic Search

    Flavia Grassi; Sergio A. Pignari; Johannes Wolf

    2011-01-01

    This paper investigates the possibility of using the powerline communications (PLC) technology to transmit data along differential dc power buses employed in spacecraft. To this end, a point-to-point interconnection between the power control and distribution unit (PCDU) and a dc\\/dc converter is consid- ered. The power bus is composed of a twisted-wire pair (TWP) above ground, and capacitive coupling and

  15. 14 CFR 129.111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 2013-01-01 2013-01-01 false Electrical wiring interconnection systems (EWIS) maintenance...COMMON CARRIAGE Continued Airworthiness and Safety Improvements § 129.111 Electrical wiring interconnection systems (EWIS)...

  16. 14 CFR 129.111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 2011-01-01 2011-01-01 false Electrical wiring interconnection systems (EWIS) maintenance...COMMON CARRIAGE Continued Airworthiness and Safety Improvements § 129.111 Electrical wiring interconnection systems (EWIS)...

  17. 14 CFR 129.111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 2012-01-01 2012-01-01 false Electrical wiring interconnection systems (EWIS) maintenance...COMMON CARRIAGE Continued Airworthiness and Safety Improvements § 129.111 Electrical wiring interconnection systems (EWIS)...

  18. 14 CFR 129.111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2010-01-01 2010-01-01 false Electrical wiring interconnection systems (EWIS) maintenance...COMMON CARRIAGE Continued Airworthiness and Safety Improvements § 129.111 Electrical wiring interconnection systems (EWIS)...

  19. 14 CFR 129.111 - Electrical wiring interconnection systems (EWIS) maintenance program.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2014-01-01 2014-01-01 false Electrical wiring interconnection systems (EWIS) maintenance...COMMON CARRIAGE Continued Airworthiness and Safety Improvements § 129.111 Electrical wiring interconnection systems (EWIS)...

  20. Magnetoimpedance effect of the Ni80Fe20/Cu composite wires: The influence of DC current imposed on the Cu base

    NASA Astrophysics Data System (ADS)

    Chen, Delu; Li, Xin; Ji, Xiaofeng; Zhao, Qiang; Ruan, Jianzhong; Zhao, Zhenjie

    2014-06-01

    In this paper, the copper composite wires of 75 ?m in diameter with a sputtered layer of Ni80Fe20 permalloy were prepared, with a DC current applied to the basal Cu terminals during the fabrication process. The influence of the DC current on the magnetic configuration and Magneto-Impedance (MI) effect was studied. The results indicate that both the current amplitude and actuation duration have significant effect on the magnetic properties of the Ni80Fe20 layer. With appropriate current applied, the induced magnetic field leads to a circumferential magnetic domain structure and reduces significantly the equivalent anisotropy field of Ni80Fe20 layer. Then, the GMI ratio of the composite wires was significantly increased. A maximum GMI of 194.8% can be reached when the current was fixed at 100 mA and the Ni80Fe20 thickness is 780 nm. If the Ni80Fe20 thickness is above 780 nm, the coercivity of the coating layer increases while the GMI ratio of the composite wire reduces, since the magnetic anisotropy of the Ni80Fe20 layer varies from circumferential to longitudinal. The results were explained combining the thermal and magnetic effects of current.

  1. Malfunction Issue of SiC-SIT Based DC Circuit Breaker in 400V DC Power Distribution Systems for Data Centers

    NASA Astrophysics Data System (ADS)

    Abe, Seiya; Yang, Sihun; Shoyama, Masahito; Ninomiya, Tamotsu; Matsumoto, Akira; Fukui, Akiyoshi

    400V DC power distribution systems for data centers require a fast response DC circuit breaker is required. The semiconductor DC circuit breaker is an important key technology in DC power distribution systems. This paper considers the malfunction of Silicon Carbide- Static Induction Transistor (SiC-SIT) based DC circuit breakers in 400V DC power distribution systems for data centers. The malfunction mechanism is explained, and a solution is proposed. Investigations are achieved by MATLAB/Simulink and experimental verification.

  2. Commissioning a Vibrating Wire System for Quadrupole Fiducialization

    SciTech Connect

    Levashov, Michael Y

    2010-12-03

    Quadrupoles will be placed between the undulator segments in LCLS to keep the electron beam focused as it passes through. The quadrupoles will be assembled with their respective undulator segments prior to being placed into the tunnel. Beam alignment will be used to center the quadrupoles, along with the corresponding undulators, on the beam. If there is any displacement between the undulator and the quadrupole axes in the assemblies, the beam will deviate from the undulator axis. If it deviates by more than 80{micro}m in vertical or 140{micro}m in horizontal directions, the undulator will not perform as required by LCLS. This error is divided between three sources: undulator axis fiducialization, quadrupole magnetic axis fiducialization, and assembly of the two parts. In particular, it was calculated that the quadrupole needs to be fiducialized to within 25{micro}m in both vertical and horizontal directions. A previous study suggested using a vibrating wire system for finding the magnetic axis of the quadrupoles. The study showed that the method has high sensitivity (up to 1{micro}m) and laid out guidelines for constructing such a system. There are 3 steps in fiducializing the quadrupole with the vibrating wire system. They are positioning the wire at the magnet center (step 1), finding the wire with position detectors (step 2), and finding the quadrupole tooling ball positions relative to the position detector tooling balls (step 3). A previous study investigated the error associated with each step by using a permanent quadrupole magnet on an optical mover system. The study reported an error of 11{micro}m for step 1 and a repeatability of 4{micro}m for step 2. However, the set up used a FARO arm to measure tooling balls and didn't allow to accurately check step 2 for errors; an uncertainty of 100{micro}m was reported. Therefore, even though the repeatability was good, there was no way to check that the error in step 2 was small. Following the recommendations of that study, we used a CMM (Coordinate Measuring Machine) instead of the FARO arm for measuring the tooling balls. In addition, a roller cam positioner system replaced the optical movers for moving the quadrupole. With the exception of the quadrupole itself, the system was identical to what will be used in fiducializing the undulator quadrupoles. In this study, we investigate the new vibrating wire set up, including the error associated with each step of fiducialization. A vibrating wire system was constructed to fiducialize the quadrupoles between undulator segments in the LCLS. This note is a continuation of previous work to study the ability of the system to fulfill the fiducialization requirements.

  3. Recycling system for printed wiring boards with mounted parts

    Microsoft Academic Search

    S. Yokoyama; Y. Ikuta; M. Iji

    1999-01-01

    A practical recycling system has been developed for printed wiring boards (PWBs) with electronic parts mounted on them. This system consists of part-removing, solder-removing and resin-board pulverizing\\/separating processes, and is effective in the recovery of useful materials. The authors have developed a part-removal apparatus which successfully removes through-hole devices as well as surface mounted devices from PWBs with almost no

  4. Crossed hot-wire data acquisition and reduction system

    NASA Technical Reports Server (NTRS)

    Westphal, R. V.; Mehta, R. D.

    1984-01-01

    The report describes a system for rapid computerized calibration acquisition, and processing of data from a crossed hot-wire anemometer is described. Advantages of the system are its speed, minimal use of analog electronics, and improved accuracy of the resulting data. Two components of mean velocity and turbulence statistics up to third order are provided by the data reduction. Details of the hardware, calibration procedures, response equations, software, and sample results from measurements in a turbulent plane mixing layer are presented.

  5. An Environmental Monitoring System with Integrated Wired and Wireless Sensors

    Microsoft Academic Search

    Jue Yang; Chengyang Zhang; Xinrong Li; Yan Huang; Shengli Fu; Miguel F. Acevedo

    2008-01-01

    Wireless sensor networks (WSN) technology has great potential to revolutionize many science and engineering domains. We present\\u000a a novel environmental monitoring system with a focus on the overall system architecture for seamless integration of wired\\u000a and wireless sensors for long-term, remote, and near-real-time monitoring. We also present a unified framework for sensor\\u000a data collection, management, visualization, dissemination, and exchange, conforming

  6. Combustibility of electrical wire and cable for rail rapid transit systems. Volume 1: Flammability

    NASA Astrophysics Data System (ADS)

    Tewarson, A.; Khan, M. M.; Steciak, J.

    1983-05-01

    The flammability of wires and cables used in rapid rail transit systems was examined to quantify the fire properties of wires and cables in a manner so that the relative fire hazards could be assessed under various fire scenarios expected in rapid rail systems. The following items were investigate: a literature review of wire and cables fires; selection of test method for combustibility evaluations of wires and cables; testing of wires and cables; and evaluation of ranking of wires and cables. An overall summary, experimental details, results and discussion, and appendices providing detailed calculations for determining the different parameters used are presented.

  7. Angular Dependence of Transport AC Losses in Superconducting Wire with Position-Dependent Critical Current Density in a DC Magnetic Field

    NASA Astrophysics Data System (ADS)

    Su, Xing-liang; Xiong, Li-ting; Gao, Yuan-wen; Zhou, You-he

    2013-07-01

    Transport AC losses play a very important role in high temperature superconductors (HTSs), which usually carry AC transport current under applied magnetic field in typical application-like conditions. In this paper, we propose the analytical formula for transport AC losses in HTS wire by considering critical current density of both inhomogeneous and anisotropic field dependent. The angular dependence of critical current density is described by effective mass theory, and the HTS wire has inhomogeneous distribution cross-section of critical current density. We calculate the angular dependence of normalized AC losses under different DC applied magnetic fields. The numerical results of this formula agree well with the experiment data and are better than the results of Norris formula. This analytical formula can explain the deviation of experimental transport current losses from the Norris formula and apply to calculate transport AC losses in realistic practical condition.

  8. Photovoltaic-wind hybrid system for permanent magnet DC motor

    NASA Astrophysics Data System (ADS)

    Nasir, M. N. M.; Lada, M. Y.; Baharom, M. F.; Jaafar, H. I.; Ramani, A. N.; Sulaima, M. F.

    2015-05-01

    Hybrid system of Photovoltaic (PV) - Wind turbine (WT) generation has more advantages and reliable compared to PV or wind turbine system alone. The aim of this paper is to model and design hybrid system of PV-WT supplying 100W permanent-magnet dc motor. To achieve the objective, both of PV and WT are connected to converter in order to get the same source of DC supply. Then both sources were combined and straightly connected to 100W permanent magnet dc motor. All the works in this paper is only applied in circuit simulator by using Matlab Simulink. The output produced from each converter is expected to be suit to the motor specification. The output produced from each renewable energy system is as expected to be high as it can support the motor if one of them is breakdown

  9. Fly-by-Wire Systems Enable Safer, More Efficient Flight

    NASA Technical Reports Server (NTRS)

    2012-01-01

    Using the ultra-reliable Apollo Guidance Computer that enabled the Apollo Moon missions, Dryden Flight Research Center engineers, in partnership with industry leaders such as Cambridge, Massachusetts-based Draper Laboratory, demonstrated that digital computers could be used to fly aircraft. Digital fly-by-wire systems have since been incorporated into large airliners, military jets, revolutionary new aircraft, and even cars and submarines.

  10. A ZCS Lossless Snubber Cells-Applied Half-Bridge Bidirectional DC—DC Converter for Automotive Electric Power Systems

    Microsoft Academic Search

    Tomokazu Mishima; Eiji Hiraki; Toshihiko Tanaka

    2006-01-01

    A new type of bidirectional DC—DC converter for electric power systems in advanced electric vehicles is proposed in this paper. This converter consists of half-bridge circuits with a high frequency transformer, which is well applicable as an interface between a high-voltage DC bus line and a low-voltage power source. In order to reduce the switching loss, newly developed ZCS loss-less

  11. Improved dynamic security assessment for AC\\/DC power systems using energy functions

    Microsoft Academic Search

    N. Fernandopulle; R. T. H. Alden

    2004-01-01

    A method is presented to integrate the dynamics of DC power flow into calculations of transient energy functions of AC\\/DC power systems. This method treats the generator input power as a function of the parameters and the input, output variables of the DC control system. By using this transient energy function, the accuracy of the stability prediction of AC\\/DC power

  12. DC Servo Controlled System Design on Bomb-Disposal Robot Algorithm

    Microsoft Academic Search

    Zhou Hongfu; Xiao Xinyan; Jiang Liangzhong

    2007-01-01

    The research on DC servomotor control system for bomb-disposal robot is proposed in the paper, which is based on PID control and PWM output for the DC motor drive. The research designed PID control for 8 DC servomotors drive in the bomb-disposal robot, and the optimize PID parameters are determined by experiment. In the design the DC servomotor control system

  13. A framework for SFC/DC system data analysis

    NASA Technical Reports Server (NTRS)

    Centeno, Martha A.

    1993-01-01

    The Shop Floor Control/Data Collection (SFC/DC) system is one of four major modules of the Integrated Work Control System being implemented at the NASA Kennedy Space Center. The SFC/DC system, which has been in operation approximately one and a half years, collects detailed information regarding the duration of tasks as well as work stoppages duration. This information needs to be effectively analyzed, so as be able to manage the shuttle processing activities under the continuous improvement philosophy. We have studied the contents and form of the SFC/DC database, and based on the results of such study, we have designed a Shop floor Modeling, Analysis, and Reporting Tool (SMART). SMART is a collection of compatible tools (off-the-shelf as well as customized C-based tools) that work cohesively to prepare inputs for the analysis models and process the various models. The feasibility of SMART has been demonstrated through an initial prototype.

  14. A Testing System for Diagnosing Misconceptions in DC Electric Circuits.

    ERIC Educational Resources Information Center

    Chang, Kuo-En; Liu, Sei-Hua; Chen, Sei-Wang

    1998-01-01

    Outlines a test-based diagnosis system for misconceptions in DC electric circuits and its three parts: problem library, problem selector and diagnoser. Discusses misconception discrimination and diagnosis theories, and reports the system supports satisfactory diagnosis. Includes an analysis of nine student misconceptions about electrical circuits…

  15. Design and development of a DC-DC converter for a fuel cell inverter system 

    E-print Network

    Gopinath, Rajesh

    2001-01-01

    This thesis outlines the design and development of a DC-DC converter for a fuel cell inverter application. The proposed DC-DC converter was designed and tested at Texas A&M to meet the specifications laid down for the '2001 Future Energy Challenge...

  16. The reliability evaluation of Cu wire Bonding by using focus ion beam system

    Microsoft Academic Search

    Zhang XiaoWen; Lin XiaoLing; Chen Yuan

    2010-01-01

    The cross sections of bonding have been made by using focus ion beam (FIB) system on the advanced chips packaged with BGA. Through the measurement of aluminum layer thickness under different bond force, the bonding reliability has been evaluated. The comparison has also been made on the interface of Au wire Bonding and Cu wire Bonding. Since the Cu wire

  17. A Concise Model of 3x7 Wire Rope Used in Cable Guardrail Systems

    Microsoft Academic Search

    Cody S Stolle

    2010-01-01

    Wire rope is a versatile, flexible, high-strength member that is used in many mechanical systems. However, due to the complexity of wire rope, analytical investigations have been relatively limited. Previous attempts to create simplified models of wire rope were not validated with physical testing and used a cumbersome beam-and-shell or beam-and-solid method for simulating the wire rope.\\u000aAn improved LS-DYNA

  18. Flat-top system of the DC-280 cyclotron

    NASA Astrophysics Data System (ADS)

    Gulbekyan, G. G.; Buzmakov, V. A.; Zarubin, V. B.; Ivanenko, I. A.; Kazarinov, N. Yu.; Karamysheva, G. A.; Franko, I.

    2013-07-01

    The flat-top cavity of the radio-frequency accelerating system designed at the Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, for the DC-280 cyclotron is described. The cyclotron is intended for increasing the capabilities and efficiency of experiments on the synthesis of super-heavy elements and an investigation of their nuclear physical and chemical properties. The DC-280 isochronous heavy-ion cyclotron will produce accelerated beam of ions in the range from neon to uranium. The parameters, design, and results of the experimental and 3D computer modeling of the flat-top cavity of the RF accelerating system of the DC-280 cyclotron are reported.

  19. Design and implementation of an automatic measurement system for DC-DC converter efficiency on a motherboard

    Microsoft Academic Search

    Ying-Win Bai; Wei-Chih Kuo

    2010-01-01

    In this paper, we design and implement an automatic measurement system for measuring the power efficiency of DC-DC converters on a motherboard. By incorporating a software module to measure the efficiency with the assistance of a LabVIEW software module, we propose a design for our virtual instrument (VI) with a front panel as a friendly user interface to control the

  20. Ship Propulsion AC\\/DC Conversion System Modeling and Design

    Microsoft Academic Search

    Giovanna Oriti; Rob M. Cuzner

    2006-01-01

    This paper presents the detailed physics-based model and design of a high voltage high power AC\\/DC power conversion system comprising a 3 to 12 phase transformer and a 24 pulse thyristor controlled rectifier. System level modeling is critical during the multi-year design of the 30-50 MW system. The goal of the modeling effort is to avoid re-designing the system which

  1. Research on BiDirectional DC-DC Converter For a Stand-Alone Photovoltaic Hybrid Energy Storage System

    Microsoft Academic Search

    Xie Jun; Zhang Xing; Zhang Chongwei; Wang Chengyue

    2010-01-01

    A novel stand-alone photovoltaic ultracapacitor\\/battery hybrid energy storage system is proposed. Compared with the traditional one, this system has high power density and high energy density, prolong the lifetime of battery, achieve the system more efficient and reliable etc. A digital control system for multiple-input bi-directional dc-dc converter is designed and implemented. Software and hardware implementation issuses are described .

  2. 270 V DC system-a highly efficient and reliable power supply system for both telecom and datacom systems

    Microsoft Academic Search

    Takashi Yamashita; Seiichi Muroyama; S. Furubo; S. Ohtsu

    1999-01-01

    A 270 V DC power supply system is superior to the conventional 48 V DC system or 200 V AC system because of its high reliability, high supply efficiency and low cost, especially as the power consumption of telecom and datacom equipment cabinets increases. Introducing 270 V DC system will require the development of several power supply components in the

  3. Mathematical simulation of DC arc furnace operation in electric power systems

    Microsoft Academic Search

    D. Stade; H. Schau; I. Aprelkov; A. Novitskiy

    1998-01-01

    Modern high-power DC electric arc furnaces (DC EAF) are considerable sources of power quality impacts in the electric supply systems. These impacts result from the feeding converters, but particularly also from the electric arc in the DC circuit. For an exact analysis of the DC EAF influence on the electric network, both the converter and the electric arc have to

  4. Improved dynamic security assessment for AC\\/DC power systems using energy functions

    Microsoft Academic Search

    Nilkamal Fernandopulle; Robert T. H. Alden

    2003-01-01

    A method is presented to integrate the dynamics of DC power flow into calculations of transient energy functions of AC\\/DC power systems. This method treats the generator input power as a function of the parameters and the input, output variables of the DC damping power controller. By using this transient energy function, the accuracy of the stability prediction of AC\\/DC

  5. Reversed diode earthing scheme in DC traction power system

    Microsoft Academic Search

    M. M. Alamuti; A. Zare; M. Savaghebi

    2008-01-01

    Reducing rail voltage and stray current corrosion all at once is one of the challenging problems in DC electrified rail transit systems. Stray current is the main reason of corrosion in the metallic parts located in the proximity of the railway. Choosing appropriate earthing scheme is an effective way to decrease corrosion intensity and providing safety for personnel. This paper

  6. Linear adaptive position control system of brushless DC servo motor

    Microsoft Academic Search

    Kiyoshi Ohishi; Kouhei Ohnishi; Masaaki Hotta; Katunori Taniguchi

    1988-01-01

    A linear adaptive position control system for a brushless DC servomotor is proposed. The state error caused by both parameter variations and force disturbance is rapidly suppressed based on the dual passive adaptive control loop; the same approach can also be used to realize model reference acceleration control. As this structure is simple, calculation time required by the total position

  7. Energy Management for Regenerative Brakes on a DC Feeding System

    Microsoft Academic Search

    Yuruki Okada; Takafumi Koseki; Satoru Sone

    Recently, regenerative brakes are implemented in trains at DC fed electric railways in Japan. Regenerative braking system converts kinetic energy to electrical energy. And other powering trains at the identical feeding circuit must consume the electrical energy. Therefore, when the electrical loads are not sufficient at feeding circuit, braking trains must squeeze regenerative power. The problem is that such braking

  8. Reliability Research for Steer-by-Wire System of Electric Vehicle

    Microsoft Academic Search

    Lijun Zhang; Lifang Wang; Chenglin Liao

    2009-01-01

    Steer-by-wire system of electric vehicle must meet the real-time and reliability requirements. An approach in how to estimate the reliability of steer-by-wire system considering the delay caused by network transmission errors is proposed. In the paper, a distributed architecture of steer-by-wire system is researched to analyze the delay time of the system, and design the TDMA slots of FlexRay bus.

  9. Bidirectional DC-DC Converter with Full-bridge \\/ Push-pull circuit for Automobile Electric Power Systems

    Microsoft Academic Search

    Koji Yamamoto; Eiji Hiraki; Toshihiko Tanaka; Mutsuo Nakaoka; Tomokazu Mishima

    2006-01-01

    In recent years, energy storage systems assisted by super capacitor have been widely researched and developed to progress power systems for the electronic vehicles. In this paper, a full-bridge\\/push-pull circuit-based bidirectional DC-DC converter and its control methods are proposed. From the results of detailed experimental demonstration, the proposed system is able to perform adequate charge and discharge operation between low-voltage

  10. Polariton dispersion of a quantum wire superlattice system

    NASA Astrophysics Data System (ADS)

    Wilson, K. S. Joseph; Amalanathan, M.; Revathy, V.; Lenin, S. Maria

    2015-06-01

    Superlattices have drawn considerable attention in the recent years. In this work, the behaviour of polaritons in a quantum wire superlattice is analysed both at the brillouin zone edge and at centre of the brillouin zone using LiNbO3/ LiTaO3 as an example. The significance of the polariton modes in both the cases are analysed. New modes on the polaritonic gap, where the propagation of electromagnetic wave is forbidden, is obtained in the system as suggested by some recent literature. The effect on nonlinear interactions of phonon polaritons in LiNbO3/ LiTaO3 superlattices is also discussed.

  11. A wire scanner system for characterizing the BNL energy recovery LINAC beam position monitor system

    SciTech Connect

    Michnoff R.; Biscardi, C.; Cerniglia, P.; Degen, C.; Gassner, D.; Hoff, L.; Hulsart, R.

    2012-04-15

    A stepper motor controlled wire scanner system has recently been modified to support testing of the Brookhaven National Laboratory (BNL) Collider-Accelerator department's Energy Recovery Linac (ERL) beam position monitor (BPM) system. The ERL BPM consists of four 9.33 mm diameter buttons mounted at 90 degree spacing in a cube with 1.875 inch inside diameter. The buttons were designed by BNL and fabricated by Times Microwave Systems. Libera brilliance single pass BPM electronic modules with 700 MHz bandpass filter, manufactured by Instrumentation Technologies, will be used to measure the transverse beam positions at 14 locations around the ERL. The wire scanner assembly provides the ability to measure the BPM button response to a pulsed wire, and evaluate and calibrate the Libera position measurement electronics. A description of the wire scanner system and test result data will be presented.

  12. DC-to-DC Solar Converter with Controlled Active Clamping System

    Microsoft Academic Search

    Karl H. Edelmoser; F. A. Himmelstoss

    2006-01-01

    In the field of electrical solar power conversion efficiency is the most important topic. In most applications a special DC-to-DC converter is necessary to couple the solar cells, operating at low DC voltages, to the inverter's DC-link. These converters with rather low input respectively high output voltage ratings have, due to the high current ratings, a relatively low efficiency. Therefore,

  13. A magnetic-less DC-DC converter for dual-voltage automotive systems

    Microsoft Academic Search

    Fang Zheng Peng; Fan Zhang; Zhaoming Qian

    2003-01-01

    The automotive industry is moving toward 42 V to meet more electrical needs. Several dual-voltage (42 and 14 V) architectures have been proposed for the transition and accommodation of 14-V loads. A DC-DC converter that connects the 42 and 14 V is one key device in any dual-voltage architecture. This paper presents a compact, efficient, magnetic-less bidirectional DC-DC converter for

  14. Novel Calibration System with Sparse Wires for CMB Polarization Receivers

    NASA Astrophysics Data System (ADS)

    Tajima, O.; Nguyen, H.; Bischoff, C.; Brizius, A.; Buder, I.; Kusaka, A.

    2012-06-01

    A curl competent (also known as B-modes) in the cosmic microwave background (CMB) polarization is a smoking gun signature of the inflationary universe. To achieve better sensitivity to this faint signal, CMB polarization experiments aim to maximize the number of detector elements, resulting in a large focal plane receiver. Detector calibration of the polarization response becomes essential. It is extremely useful to be able to calibrate "simultaneously" all detectors on the large focal plane. We developed a novel calibration system that rotates a large "sparse" grid of metal wires, in front of and fully covering the field of view of the focal plane receiver. Polarized radiation is created via the reflection of ambient temperature photons from the wire surface. Since the detector has a finite beam size, the observed signal is convolved with the beam property. The intensity of the of the calibrator is reasonable (a few Kelvin or less) compared to sky temperature for typical observing conditions (˜10 K). The system played a successful role for receiver calibration of QUIET, a CMB polarization experiment located in the Atacama desert in Chile. The successful performance revealed that this system is applicable to other experiments based on different technologies, e.g. TES bolometers.

  15. Metal woven wire cloth feeding system for gas bearings

    Microsoft Academic Search

    G. Belforte; T. Raparelli; V. Viktorov; A. Trivella

    2009-01-01

    The paper presents an experimental investigation of pneumatic resistances constructed using woven wire cloth. Tests were carried out on commercial Touraille stainless steel wire cloth featuring different mesh sizes.Two types of experiments were performed: (a) Mass flow rate through single resistances was measured with different upstream and downstream pressures and wire mesh sizes. (b) Pressure distribution and mass flow rate

  16. A Laser-Wire System for the International Linear Collider

    SciTech Connect

    Delerue, N.; Dixit, S.; Gannaway, F.; Howell, D.; Qurshi, M.; Blair, G.; Boogert, S.; Boorman, G.; Driouichi, C.; Deacon, L.; Aryshev, A.; Karataev, P.; Terunuma, N.; Urakawa, J.; Brachmann, A.; Frisch, J.; Ross, M.; /Oxford U. /Royal Holloway, U. of London /KEK, Tsukuba /SLAC

    2009-04-30

    A new laser-wire has been installed in the extraction line of the ATF at KEK. It aims at demonstrating that laser-wires can be used to measure micrometre scale beam size. In parallel, studies have been made to specify a laser suitable for the ILC laser-wires.

  17. An Isolated Bidirectional DC-DC Converter based Super-Capacitor Interface for Automobile Electric Power Systems

    Microsoft Academic Search

    Eiji Hiraki; Koji Yamamoto; Toshihiko Tanaka; Tomokazu Mishima; Mutsuo Nakaoka

    2006-01-01

    In recent years, power electronic energy storage systems using super capacitor bank have been widely studied and developed for the electronic vehicles. In this paper, a full-bridge\\/centertapped push-pull circuit-based bidirectional DC-DC converter and its control method are proposed and discussed. From the results of detailed experimental demonstration, the proposed system is able to perform adequate charging and discharging operation between

  18. Electromagnetic Energy Harvesting Circuit With Feedforward and Feedback DC–DC PWM Boost Converter for Vibration Power Generator System

    Microsoft Academic Search

    Xinping Cao; Wen-Jen Chiang; Ya-Chin King; Yi-Kuen Lee

    2007-01-01

    This paper presents an integrated vibration power generator system. The system consists of a mini electromagnetic vibration power generator and a highly efficient energy harvesting circuit implemented on a minute printed circuit board and a 0.35-mum CMOS integrated chip. By introducing a feedback control into the dc-dc pulsewidth modulation (PWM) boost converter with feedforward control, the energy harvesting circuit can

  19. Output feedback trajectory stabilization of the uncertainty DC servomechanism system.

    PubMed

    Aguilar-Ibañez, Carlos; Garrido-Moctezuma, Ruben; Davila, Jorge

    2012-11-01

    This work proposes a solution for the output feedback trajectory-tracking problem in the case of an uncertain DC servomechanism system. The system consists of a pendulum actuated by a DC motor and subject to a time-varying bounded disturbance. The control law consists of a Proportional Derivative controller and an uncertain estimator that allows compensating the effects of the unknown bounded perturbation. Because the motor velocity state is not available from measurements, a second-order sliding-mode observer permits the estimation of this variable in finite time. This last feature allows applying the Separation Principle. The convergence analysis is carried out by means of the Lyapunov method. Results obtained from numerical simulations and experiments in a laboratory prototype show the performance of the closed loop system. PMID:22884179

  20. Automated visual inspection system for IC bonding wires using morphological processing

    NASA Astrophysics Data System (ADS)

    Tsukahara, Hiroyuki; Nakashima, Masato; Sugawara, Takehisa

    1991-02-01

    This paper discusses an automated visual inspection system for IC bonding wires that uses high-contrast image capture and an accurate bonding-ball measurement algorithm. On IC assembly lines visual inspection is vital to maintaining IC reliability. Wire bonding requires the automated evaluation of bonding quality to maintain productivity. Both bonding balls and wires must be inspected to evaluate bonding quality. We developed a bonding-ball measurement algorithm based on subpixel and morphological techniques and a wire inspection algorithm based on border following. The automated inspection system measures ball diameters to an accuracy within jim which corresponds to one-half pixel taking 0. 2 seconds to inspect a wire and ball. Paired with a wire bonder the inspection system configures a fully automatic bonding system.

  1. Active disturbance rejection control in steering by wire haptic systems.

    PubMed

    Rodriguez-Angeles, A; Garcia-Antonio, J A

    2014-07-01

    This paper introduces a steering by wired haptic system based on disturbance rejection control techniques. High gain Generalized Proportional Integral (GPI) observers are considered for the estimation of tire and steering wheel dynamic disturbances. These disturbances are on line canceled to ensure tracking between the commanded steering wheel angle and the tire orientation angle. The estimated disturbances at the steering rack are feedback to the steering wheel to provide a haptic interface with the driver. The overall system behaves as a bilateral master-slave system. Very few sensors and minimum knowledge of the dynamic model are required. Experimental results are presented on a prototype platform that consists on: (1) half of the steering rack of a beetle VW vehicle, (2) a steering wheel. PMID:23978660

  2. Electrostatic coalescence system with independent AC and DC hydrophilic electrodes

    DOEpatents

    Hovarongkura, A. David (Arlington, VA); Henry, Jr., Joseph D. (Morgantown, WV)

    1981-01-01

    An improved electrostatic coalescence system is provided in which independent AC and DC hydrophilic electrodes are employed to provide more complete dehydration of an oil emulsion. The AC field is produced between an AC electrode array and the water-oil interface wherein the AC electrode array is positioned parallel to the interface which acts as a grounded electrode. The emulsion is introduced into the AC field in an evenly distributed manner at the interface. The AC field promotes drop-drop and drop-interface coalescence of the water phase in the entering emulsion. The continuous oil phase passes upward through the perforated AC electrode array and enters a strong DC field produced between closely spaced DC electrodes in which small dispersed droplets of water entrained in the continuous phase are removed primarily by collection at hydrophilic DC electrodes. Large droplets of water collected by the electrodes migrate downward through the AC electrode array to the interface. All phase separation mechanisms are utilized to accomplish more complete phase separation.

  3. Multi-kw dc power distribution system study program

    NASA Technical Reports Server (NTRS)

    Berkery, E. A.; Krausz, A.

    1974-01-01

    The first phase of the Multi-kw dc Power Distribution Technology Program is reported and involves the test and evaluation of a technology breadboard in a specifically designed test facility according to design concepts developed in a previous study on space vehicle electrical power processing, distribution, and control. The static and dynamic performance, fault isolation, reliability, electromagnetic interference characterisitics, and operability factors of high distribution systems were studied in order to gain a technology base for the use of high voltage dc systems in future aerospace vehicles. Detailed technical descriptions are presented and include data for the following: (1) dynamic interactions due to operation of solid state and electromechanical switchgear; (2) multiplexed and computer controlled supervision and checkout methods; (3) pulse width modulator design; and (4) cable design factors.

  4. Motor vehicle electrical system providing multiple DC voltages

    Microsoft Academic Search

    1987-01-01

    This patent describes a multiple DC voltage electrical system for an automotive vehicle, comprising: a three-phase AC generator driven by the engine of the vehicle for producing a three-phase AC voltage across three-phase output windings connected in a wye configuration having a neutral node; means for connecting the neutral node of the wye configured three-phase output windings of the generator

  5. Space charge accumulation in polymeric high voltage DC cable systems

    Microsoft Academic Search

    R. Bodega

    2006-01-01

    One of the intrinsic properties of the polymeric high voltage (HV) direct current (DC) cable insulation is the accumulation of electrostatic charges. Accumulated charges distort the initial Laplacian distribution of the electric field, leading to a local field enhancement that may cause insulation degradation and premature breakdown of the system.\\u000aThe general objective of the present study is to obtain

  6. ZVS-SR bidirectional DC-DC converter for supercapacitor-applied automotive electric energy storage systems

    Microsoft Academic Search

    T. Mishima; Eiji Hiraki

    2005-01-01

    This paper explores a bidirectional DC-DC converter for supercapacitor-based energy storage systems in automotive applications. The presented converter consists of a half-bridge converter and a current-fed push-pull inverter with a transformer-isolation. Owing to the isolation topology, the supercapacitor can be operated in the wide voltage range, which results in an increase in the utilization of supercapacitor-stored energy. In order to

  7. Master–Slave Current-Sharing Control of a Parallel DC–DC Converter System Over an RF Communication Interface

    Microsoft Academic Search

    Sudip K. Mazumder; Muhammad Tahir; Kaustuva Acharya

    2008-01-01

    Using analog wireless communication, we demonstrate a master-slave load-sharing control of a parallel dc-dc buck converter system, thereby eliminating the need for physical connection to distribute the control signal among the converter modules. The current reference for the slave modules is provided by the master module using radio-frequency (RF) transmission, thereby ensuring even sharing of the load current. The effect

  8. NASA/Ames Research Center DC-8 data system

    NASA Technical Reports Server (NTRS)

    Cherniss, S. C.; Scofield, C. P.

    1991-01-01

    In-flight facility data acquisition, distribution, and recording on the NASA Ames Research Center (ARC) DC-8 are performed by the Data Acquisition and Distribution System (DADS). Navigational and environmental data collected by the DADS are converted to engineering units and distributed real-time to investigator stations once per second. Selected engineering units data are printed and displayed on closed circuit television monitors throughout flights. An in-flight graphical display of the DC-8 flight track (with barbs indicating wind direction and magnitude) has recently been added to the DADS capabilities. Logging of data run starts/stops and commentary from the mission director are also provided. All data are recorded to hard disk in-flight and archived to tape medium post-flight. Post-flight, hard copies of the track map and mission director's log are created by the DADS. The DADS is a distributed system consisting of a data subsystem, an Avionic Serial Data-to-VMEbus (ASD2VME) subsystem, and a host subsystem. Each subsystem has a dedicated central processing unit (CPU) and is capable of stand-alone operation. All three subsystems are housed in a single 20-slot VME chassis and communicate with each other over the VMEbus. The data and host subsystems are briefly discussed, and the DC-8 DADS internal configuration and system block diagram are presented.

  9. 78 FR 1 - Prevailing Rate Systems; Abolishment of the Washington, DC, Special Wage Schedule for Printing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-02

    ...Abolishment of the Washington, DC, Special Wage Schedule for Printing Positions AGENCY: U.S. Office of Personnel Management...Washington, DC, Federal Wage System special wage schedule for printing and lithographic positions. The final rule incorrectly...

  10. A nonlinear robust HVDC control for a parallel AC/DC power system

    E-print Network

    Qu, Zhihua

    recognized that, through an HVDC transmission line, fast electronic control can be applied on the DC power, controlling DC line transmission power can improve stability of the AC system after a major disturbanceA nonlinear robust HVDC control for a parallel AC/DC power system Hongzhi Cai a , Zhihua Qu b

  11. Research on 1Wire Bus Temperature Monitoring System

    Microsoft Academic Search

    Wang Jingzhuo; Gong Chenglong

    2007-01-01

    Based on 1-Wire bus technology, the 1-Wire bus temperature monitoring MicroLan was designed through using computer serial communication port, protocol transform chip DS2480 and 1-Wire bus digital temperature sensor DS18B20. The structure, character, ROM command, function command of DS18B20 and operating principle of DS2480B were analyzed. Consequently, the interface circuit between 1-Wrie bus and COM port is provided. At the

  12. System Design Considerations for High data Rate Communications Over Multi-wire Overhead Power-

    E-print Network

    Kavehrad, Mohsen

    System Design Considerations for High data Rate Communications Over Multi-wire Overhead Power communication system by means of coding and adaptive resource allocation. In section II, a brief review, PA 16802 Abstract ­ Broadband power-line communications over multi-wire overheard lines using

  13. CSMP (Continuous System Modeling Program) modeling of brushless DC motors

    NASA Astrophysics Data System (ADS)

    Thomas, S. M.

    1984-09-01

    Recent improvements in rare earth magnets have made it possible to construct strong, lightweight, high horsepower DC motors. This has occasioned a reassessment of electromechanical actuators as alternatives to comparable pneumatic and hydraulic systems for use in flight control actuators for tactical missiles. This thesis develops a low-order mathematical model for the simulation and analysis of brushless DC motor performance. This model is implemented in CSMP language. It is used to predict such motor performance curves as speed, current and power versus torque. Electronic commutation based on Hall effect sensor positional feedback is simulated. Steady state motor behavior is studied under both constant and variable air gap flux conditions. The variable flux takes two different forms. In the first case, the flux is varied as a simple sinusoid. In the second case, the flux is varied as the sum of a sinusoid and one of its harmonics.

  14. Modelling, simulation and construction of a dc/dc boost power converter: a school experimental system

    NASA Astrophysics Data System (ADS)

    Silva-Ortigoza, R.; Silva-Ortigoza, G.; Hernández-Guzmán, V. M.; Saldaña-González, G.; Marcelino-Aranda, M.; Marciano-Melchor, M.

    2012-05-01

    We introduce a dc/dc boost power converter as a didactic prototype intended to support courses on electric circuit analysis experimentally. The corresponding mathematical model is obtained, the converter is designed and an experimental setup is described, constructed and tested. Simplicity of construction as well as low cost of components renders the feasible introduction of this equipment in undergraduate laboratories.

  15. DC Bus Regulation with a Flywheel Energy Storage System

    NASA Technical Reports Server (NTRS)

    Kenny, Barbara H.; Kascak, Peter E.

    2003-01-01

    This paper describes the DC bus regulation control algorithm for the NASA flywheel energy storage system during charge, charge reduction and discharge modes of operation. The algorithm was experimentally verified with results given in a previous paper. This paper presents the necessary models for simulation with detailed block diagrams of the controller algorithm. It is shown that the flywheel system and the controller can be modeled in three levels of detail depending on the type of analysis required. The three models are explained and then compared using simulation results.

  16. A control system for dc arc furnaces for power quality improvements

    Microsoft Academic Search

    G. C. Lazaroiu; D. Zaninelli

    2010-01-01

    The dc arc furnaces are highly disturbing loads for transmission and distribution networks. The present paper proposes and implements an ac–dc converter control system for power quality improvements taking into account both flicker levels and harmonics at the point of common coupling. Different set of parameters for the proportional–integral controller are investigated for optimizing the dc arc furnace power quality

  17. Virtual Instrument Systems in Reality (VISIR) for Remote Wiring and Measurement of Electronic Circuits on Breadboard

    ERIC Educational Resources Information Center

    Tawfik, M.; Sancristobal, E.; Martin, S.; Gil, R.; Diaz, G.; Colmenar, A.; Peire, J.; Castro, M.; Nilsson, K.; Zackrisson, J.; Hakansson, L.; Gustavsson, I.

    2013-01-01

    This paper reports on a state-of-the-art remote laboratory project called Virtual Instrument Systems in Reality (VISIR). VISIR allows wiring and measuring of electronic circuits remotely on a virtual workbench that replicates physical circuit breadboards. The wiring mechanism is developed by means of a relay switching matrix connected to a PCI…

  18. Monitoring Battery System for Electric Vehicle, Based On "One Wire" Technology

    E-print Network

    Catholic University of Chile (Universidad Católica de Chile)

    Monitoring Battery System for Electric Vehicle, Based On "One Wire" Technology Javier Ibáñez Vial with technology "One Wire"®, which allows transmitting data from all batteries through a serial bus isolation. In this way, each battery can be replaced in case of failure and it is possible to view

  19. Effects of bonding pressure on nonlinear dynamic characteristic of the ultrasonic wire bonding system

    Microsoft Academic Search

    Lei Lv; Lei Han

    2008-01-01

    Ultrasonic wire bonding is one of the main methods in the package of the chip and substrate of the chip. The vibrations of transducer were tested. Surrogate-data method of phase-randomized based on correlation dimension is proposed to identify the nonlinear chaos of data obtained by ultrasonic wire bonding system. The result indicate there is nonlinear factor in the axial direction

  20. X-wing fly-by-wire vehicle management system

    NASA Technical Reports Server (NTRS)

    Fischer, Jr., William C. (Inventor)

    1990-01-01

    A complete, computer based, vehicle management system (VMS) for X-Wing aircraft using digital fly-by-wire technology controlling many subsystems and providing functions beyond the classical aircraft flight control system. The vehicle management system receives input signals from a multiplicity of sensors and provides commands to a large number of actuators controlling many subsystems. The VMS includes--segregating flight critical and mission critical factors and providing a greater level of back-up or redundancy for the former; centralizing the computation of functions utilized by several subsystems (e.g. air data, rotor speed, etc.); integrating the control of the flight control functions, the compressor control, the rotor conversion control, vibration alleviation by higher harmonic control, engine power anticipation and self-test, all in the same flight control computer (FCC) hardware units. The VMS uses equivalent redundancy techniques to attain quadruple equivalency levels; includes alternate modes of operation and recovery means to back-up any functions which fail; and uses back-up control software for software redundancy.

  1. A novel ZVS step-up push-pull type isolated LLC series resonant dc-dc converter for UPS systems and its topology variations

    Microsoft Academic Search

    Wei Chen; Zhengyu Lu; Xiaofeng Zhang; Shaoshi Ye

    2008-01-01

    High dc gain step-up dc-dc converter continues drawing lots of interests in on-line UPS systems to interface the battery power to unity. Conventional methods, in which using non-isolated converters including cascade converters, can achieve high dc gain but compromise efficiency, while the situation of employing isolated converters is just opposite. To combine the merits of these two type converters and

  2. Study of degradation within DC93-009 and DC93-029 silicone resin systems

    SciTech Connect

    Ewanowski, L.C.

    1986-02-01

    Two Dow Corning potting/filling resins (DC93-009 and DC93-029) mixed and used in production at the Mason and Hanger - Silas Mason Co., Inc., Pantex Plant, have shown to self-polymerize without the presence of curing agent. Each component that goes into one lot of these resins was characterized by chemical and physical methods. The active crosslinker was found to have reacted prematurely with moisture and had lost much of its ability to react with prepolymer. A newly purchased lot of crosslinker has been used to make production lots of both DC93-009 and DC93-029 resins. The new production lots are meeting all required specifications, and the new crosslinker is being tested weekly to monitor product integrity. 11 figs., 2 tabs.

  3. A low-voltage CMOS DC-DC converter for a portable battery-operated system

    Microsoft Academic Search

    Anthony J. Stratakos; Seth R. Sanders; Robert W. Brodersen

    1994-01-01

    Motivated by emerging battery-operated applications that demand compact, lightweight, and highly efficient DC-DC power converters, a buck circuit is presented in which all active devices are integrated on a single chip using a standard 1.2 ? CMOS process. The circuit delivers 750 mW at 1.5 V from a 6 V battery. To effectively eliminate switching loss at high operating frequencies,

  4. A DB\\/DC platform for real-time operating systems based on CTRON specifications

    Microsoft Academic Search

    Takuo Nishihara; Junichi Kikuchi; Tomoji Takehisa

    1992-01-01

    A database and data communication (DB\\/DC) platform was developed for real-time operating systems based on CTRON specifications in order to create high performance online transaction processing systems such as network operation control systems. The DB\\/DC platform is designed to be portable and to achieve high performance. The authors describe the software architecture of the DB\\/DC platform for real-time operating systems

  5. Comparison of wire and fiber optics data transfer systems for large military aircraft

    Microsoft Academic Search

    Kenneth Trumble; Charlotte C. Zelon

    1979-01-01

    Methods for comparing the life-cycle cost of fiber optics and wire data transfer systems on large military aircraft are established. Using the B-1 as an example, the applicability of fiber optics to avionics\\/electrical systems on large aircraft is identified. Conceptual fiber optics data transfer systems are described. The present wire and the conceptual fiber optics designs form a basis for

  6. Evolution of the design of a second generation FireWire based data acquisition system

    Microsoft Academic Search

    T. K. Lewellen; R. S. Miyaoka; L. R. MacDonald; D. DeWitt; M. Haselman; S. Hauck

    2010-01-01

    Our laboratory has previously reported on the basic design concepts of an updated FireWire based data acquisition system for depth-of-interaction detector systems designed at the University of Washington. The new version of our data acquisition system leverages the capabilities of modern field programmable gate arrays (FPGA) and puts almost all functions into the FPGA, including the FireWire elements, the embedded

  7. DC/AC Circuits: Course Materials

    NSDL National Science Digital Library

    This course provided by eSyst describes DC/AC circuits. An introduction explains the traditional view and systems view of this topic. The course includes numerous instructor presentations, student guides, and student learning outcomes. Additional materials are grouped by topic such as circuits, semiconductors, and wiring. Users must create a free, quick login in order to download the materials.

  8. Active dc filter for HVDC system--A test installation in the Konti-Skan DC link at Lindome converter station

    SciTech Connect

    Zhang, Wenyan; Asplund, G. (ABB Power Systems, Ludvika (Sweden). HVDC Division); Aberg, A. (ABB Corporate Research, Lund (Sweden). Dept. of Man-Machine Communication); Jonsson, U. (Svenska Kraftnaet, Vaellingby (Sweden)); Loeoef, O. (Vattenfall AB, Trollhaettan (Sweden). Region Vaestsverige)

    1993-07-01

    The purpose of introducing active dc filters is to meet the more and more stringent requirement from power utilities on limiting telephone interference caused by harmonic currents from HVdc transmission lines, without unnecessarily increasing the cost of HVdc stations. An active dc filter installed in the Konti-Skan HVdc link is described. The active dc filter is connected at the bottom of an existing passive dc filter at the Lindome station. The active dc filter includes optic harmonic current measuring unit, control system, protection and supervision system, PWM power amplifier, high-frequency transformer, surge arrester, and coupling apparatuses. The active dc filter has small physical size and occupies small ground area. The performance of the active dc filter for eliminating the disturbing harmonics is excellent. To achieve comparable results by passive filters would require something like ten times more high voltage equipment.

  9. Beam Emittance Measurement with Laser Wire Scanners in the ILC Beam Delivery System

    SciTech Connect

    Agapov, I.; /CERN; Blair, G.A.; /Royal Holloway, U. of London; Woodley, M.; /SLAC

    2008-02-01

    Accurate measurement of the beam phase-space is essential for the next generation of electron accelerators. A scheme for beam optics optimization and beam matrix reconstruction algorithms for the diagnostics section of the beam delivery system of the International Linear Collider based on laser-wire beam profile monitors are discussed. Possible modes of operation of the laser-wire system together with their corresponding performance are presented. Based on these results, prospects for reconstructing the ILC beam emittance from representative laser-wire beam size measurements are evaluated.

  10. Application of Superconducting Power Cables to DC Electric Railway Systems

    NASA Astrophysics Data System (ADS)

    Ohsaki, Hiroyuki; Lv, Zhen; Sekino, Masaki; Tomita, Masaru

    For novel design and efficient operation of next-generation DC electric railway systems, especially for their substantial energy saving, we have studied the feasibility of applying superconducting power cables to them. In this paper it is assumed that a superconducting power cable is applied to connect substations supplying electric power to trains. An analysis model line was described by an electric circuit, which was analyzed with MATLAB-Simulink. From the calculated voltages and currents of the circuit, the regenerative brake and the energy losses were estimated. In addition, assuming the heat loads of superconducting power cables and the cryogenic efficiency, the energy saving of the total system was evaluated. The results show that the introduction of superconducting power cables could achieve the improved use of regenerative brake, the loss reduction, the decreased number of substations, the reduced maintenance, etc.

  11. A reconfiguration algorithm for a DC Zonal Electric Distribution System based on graph theory methods

    Microsoft Academic Search

    Julia P. Certuche-Alzate; Miguel Vélez-Reyes

    2009-01-01

    Modern DC power electric distribution system requires high stability under failure conditions. In general, the requirements of installed loads are nearly close to the maximum capacity supplied by a generator, and when a fault occurs produces an immediate change in the system topology. Therefore, DC power electric distribution system requires fast reconfiguration. This article presents an algorithm for network reconfiguration

  12. A Theory of Control for a Class of Electronic Power Processing Systems: Energy-Storage DC-To-DC Converters. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Burns, W. W., III

    1977-01-01

    An analytically derived approach to the control of energy-storage dc-to-dc converters, which enables improved system performance and an extensive understanding of the manner in which this improved performance is accomplished, is presented. The control approach is derived from a state-plane analysis of dc-to-dc converter power stages which enables a graphical visualization of the movement of the system state during both steady state and transient operation. This graphical representation of the behavior of dc-to-dc converter systems yields considerable qualitative insight into the cause and effect relationships which exist between various commonly used converter control functions and the system performance which results from them.

  13. Transient analysis of an HTS DC power cable with an HVDC system

    NASA Astrophysics Data System (ADS)

    Dinh, Minh-Chau; Ju, Chang-Hyeon; Kim, Jin-Geun; Park, Minwon; Yu, In-Keun; Yang, Byeongmo

    2013-11-01

    The operational characteristics of a superconducting DC power cable connected to a highvoltage direct current (HVDC) system are mainly concerned with the HVDC control and protection system. To confirm how the cable operates with the HVDC system, verifications using simulation tools are needed. This paper presents a transient analysis of a high temperature superconducting (HTS) DC power cable in connection with an HVDC system. The study was conducted via the simulation of the HVDC system and a developed model of the HTS DC power cable using a real time digital simulator (RTDS). The simulation was performed with some cases of short circuits that may have caused system damage. The simulation results show that during the faults, the quench did not happen with the HTS DC power cable because the HVDC controller reduced some degree of the fault current. These results could provide useful data for the protection design of a practical HVDC and HTS DC power cable system.

  14. Transient stability analysis of AC\\/DC power system based on transient energy function

    Microsoft Academic Search

    Y. Z. Lin; Z. X. Cai; Q. Mo

    2008-01-01

    In this paper, a transient energy function for AC\\/DC power systems is used to evaluate critical clearing times with consideration of the DC dynamics. The generator angular speeds, rotor angles and voltages at the HVDC link's AC buses are explicit variables in the transient energy function. A method for computing the transient energy function numerically is proposed. In the method,

  15. An Optimal Control Strategy for DC Bus Voltage Regulation in Photovoltaic System with Battery Energy Storage

    PubMed Central

    Daud, Muhamad Zalani; Mohamed, Azah; Hannan, M. A.

    2014-01-01

    This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV) system with battery energy storage (BES). The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way, the regulation of DC bus voltage of the PV/BES system can be enhanced as compared to the conventional regulation that is solely based on the voltage-sourced converter (VSC). For the grid side VSC (G-VSC), two control methods, namely, the voltage-mode and current-mode controls, are applied. For control parameter optimization, the simplex optimization technique is applied for the G-VSC voltage- and current-mode controls, including the BES DC/DC buck-boost converter controllers. A new set of optimized parameters are obtained for each of the power converters for comparison purposes. The PSCAD/EMTDC-based simulation case studies are presented to evaluate the performance of the proposed optimized control scheme in comparison to the conventional methods. PMID:24883374

  16. Characterization and application of Shape Memory Alloy wires for micro and meso positioning systems

    NASA Astrophysics Data System (ADS)

    Khan, Afzal

    The properties of Shape Memory Alloy (SMA) wires are determined by experimentation, and previously used experimental equipment contributes to measurement errors in data. In this study, various characterization experiments are designed and carried out using a precision characterization instrument for shape memory alloy wires to determine the properties and parameters of the alloy. These experiments demonstrate the behavior of SMA wires under different thermal and loading conditions as they occur in actuation applications. As SMA wires go through phase transformation, a significant amount of contraction force is produced. This actuation force has been used in bias spring actuators and differential actuators. In this dissertation, the force generated during the twinning of martensite is used to actuate positioning systems with small displacements at the micrometer level. A micropositioning system is designed and tested that has a positioning accuracy of about +/-0.15 mum. A relation between the current input and the displacement output is determined for the specific preload. The transformation force generated during the phase change from martensite to austenite is used as an actuation force for a second positioning system that uses linear bearing with a displacement range of about a millimeter. This positioning system actuated with a single nitinol wire and guided by symmetric parallel diaphragm flexures, was designed and tested. The actuation is repeatable to about +/-15 mum with variation of about +/-5 mum in postion at steady temperature.

  17. Comparison of three phase current source inverters and voltage source inverters linked with DC to DC boost converters for fuel cell generation systems

    Microsoft Academic Search

    M. Mohr; F. W. Fuchs

    2005-01-01

    Three phase current source inverters (CSI) and voltage source inverters linked with a DC to DC boost converter (VSI+BC) are appropriate solutions to convert electrical energy for distributed fuel cell generation systems. The performance of CSI's and VSI+BC's in this application is shown and both topologies are compared to each other concerning their power semiconductor design rating and their semiconductor

  18. The DC-SQUID-based Magnetocardiographic Systems for Clinical Use

    NASA Astrophysics Data System (ADS)

    Maslennikov, Yu. V.; Primin, M. A.; Slobodchikov, V. Yu.; Khanin, V. V.; Nedayvoda, I. V.; Krymov, V. A.; Okunev, A. V.; Moiseenko, E. A.; Beljaev, A. V.; Rybkin, V. S.; Tolcheev, A. V.; Gapelyuk, A. V.

    The new line of dc-SQUID-based magnetocardiographic (MCG) systems (named as the "MAG-SCAN"-family) is designed, fabricated and tested. These systems are intended for routine MCG investigations of patients at conditions of real clinical electrophysiological labs. The "MAG-SCAN"-family includes the line of MCG devices compatible in terms of hardware and software with number of measuring channels from 1 to 36. Experimental prototypes of 7- and 9-channel MCG-systems (the models "MAG-SCAN-07" and "MAG-SCAN-09" fabricated at CRYOTON Co. Ltd.) were installed in a few hospitals of Moscow city and operated in an unshielded environment of usual clinical labs. Well balanced second-order gradiometers have been used for MCG data recording. They demonstrated an intrinsic noise level better than 5 fT/?Hz. The total noise level of about 20-40 fT/?Hz was measured at urban conditions of Moscow city. The package of special software (named as the "SOFTMAG") was developed as two autonomous subsystems that allow the preprocessing of the heart magnetic signals and the spatio-temporal analysis of the field characteristics and the field sources. The software employs the algorithms for the analysis and estimation of the spatio-temporal characteristics of the heart magnetic field and the correspondent electrical currents distributions. More than 2000 investigations of different volunteers including healthy persons, patients with high blood-pressure, ischemic disease (IHD), chronic obstructive pulmonary disease (COPD) and bronchial asthma (BA) were carried out and sets of MCG-parameters specific for each group were found.

  19. dc and ac Josephson effect in a superconductor{endash}Luttinger-liquid{endash}superconductor system

    SciTech Connect

    Fazio, R. [Institut fuer Theoretische Festkoerperphysik, Universtitaet Karlsruhe, 76128 Karlsruhe (Germany)] [Institut fuer Theoretische Festkoerperphysik, Universtitaet Karlsruhe, 76128 Karlsruhe (Germany); [Istituto di Fisica, Universita di Catania, viale A. Doria 6, 95129 Catania (Italy); Hekking, F.W. [Theoretical Physics Institute, University of Minnesota, 116 Church Street SE, Minneapolis, Minnesota 55455 (United States)] [Theoretical Physics Institute, University of Minnesota, 116 Church Street SE, Minneapolis, Minnesota 55455 (United States); Odintsov, A.A. [Department of Applied Physics, Delft University of Technology, P.O. Box 5046, 2600 GA Delft (The Netherlands)] [Department of Applied Physics, Delft University of Technology, P.O. Box 5046, 2600 GA Delft (The Netherlands); [Nuclear Physics Institute, Moscow State University, Moscow 119899 GSP (Russia)

    1996-03-01

    We calculate both the dc and the ac Josephson current through a 1-D system of interacting electrons, connected to two superconductors by tunnel junctions. We treat the (repulsive) Coulomb interaction in the framework of the one-channel, spin-1/2 Luttinger model. The Josephson current is obtained for two geometries of experimental relevance: a quantum wire and a ring. At T=0, the critical current is found to decay algebraically with increasing distance {ital d} between the junctions. The decay is characterized by an exponent which depends on the strength of the interaction. At finite temperatures {ital T}, lower than the superconducting transition temperature {ital T}{sub {ital c}}, there is a crossover from algebraic to exponential decay of the critical current as a function of {ital d}, at a distance of the order of {h_bar}{ital v}{sub {ital F}}/{ital k}{sub {ital BT}}. Moreover, the dependence of critical current on temperature shows nonmonotonic behavior. If the Luttinger liquid is confined to a ring of circumference {ital L}, coupled capacitively to a gate voltage and threaded by a magnetic flux, the Josephson current shows remarkable parity effects under the variation of these parameters. For some values of the gate voltage and applied flux, the ring acts as a {pi} junction. These features are robust against thermal fluctuations up to temperatures on the order of {h_bar}{ital v}{sub {ital F}}/{ital k}{sub {ital BL}}. For the wire geometry, we have also studied the ac-Josephson effect. The amplitude and the phase of the time-dependent Josephson current are affected by electron-electron interactions. Specifically, the amplitude shows pronounced oscillations as a function of the bias voltage due to the difference between the velocities of spin and charge excitations in the Luttinger liquid. Therefore, the ac-Josephson effect can be used as a tool for the observation of {ital spin}-{ital charge} separation. {copyright} {ital 1996 The American Physical Society.}

  20. Leaping multiple headers in a single bound: wire-speed parsing using the Kangaroo system

    E-print Network

    Zhou, Yuanyuan

    Leaping multiple headers in a single bound: wire-speed parsing using the Kangaroo system Christos parsers. In this paper, we describe the design and implementation of the Kangaroo system, a flexible that traverse the parse tree one protocol at a time are too slow, Kangaroo uses lookahead to parse several

  1. Combined Operation of AC and DC Distribution System with Distributed Generation Units

    NASA Astrophysics Data System (ADS)

    Noroozian, Reza; Abedi, Mehrdad; Gharehpetian, Gevorg

    2010-07-01

    This paper presents a DC distribution system which has been supplied by external AC systems as well as local DG units in order to demonstrate an overall solution to power quality issue. In this paper, the proposed operation method is demonstrated by simulation of power transfer between external AC systems, DG units, AC and DC loads. The power flow control in DC distribution system has been achieved by network converters and DG converters. Also, the mathematical model of the network, DG and load converters are obtained by using the average technique, which allows converter systems accurately simulated and control strategies for this converters is achieved. A suitable control strategy for network converters has been proposed that involves DC voltage droop regulator and novel instantaneous power regulation scheme. Also, a novel control technique has been proposed for DG converters. In this paper, a novel control system based on stationary and synchronously rotating reference frame has been proposed for load converters for supplying AC loads connected to the DC bus by balanced voltages. The several case studies have been studied based on proposed methods. The simulation results show that DC distribution systems including DG units can improve the power quality at the point of common coupling (PCC) in the power distribution system or industrial power system.

  2. 77 FR 74347 - Prevailing Rate Systems; Abolishment of the Washington, DC, Special Wage Schedule for Printing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-14

    ...Washington, DC, Special Wage Schedule for Printing Positions AGENCY: U.S. Office of Personnel...Wage System (FWS) special wage schedule for printing and lithographic positions. Printing and lithographic employees in the...

  3. 77 FR 41247 - Prevailing Rate Systems; Abolishment of the Washington, DC, Special Wage Schedule for Printing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-13

    ...Washington, DC, Special Wage Schedule for Printing Positions AGENCY: U.S. Office of Personnel...Wage System (FWS) special wage schedule for printing and lithographic positions. Printing and lithographic employees in the...

  4. Low speed control of a DC motor driving a mechanical system with fuzzy adaptive compensation

    E-print Network

    Hyun, Dongyoon

    1997-01-01

    A fuzzy adaptive feedforward control scheme in conjunction with classical feedback control is proposed for the low speed control of DC motors driving mechanical systems in the presence of friction. In the fuzzy adaptive scheme, a fuzzy logic based...

  5. Low speed control of a DC motor driving a mechanical system with fuzzy adaptive compensation 

    E-print Network

    Hyun, Dongyoon

    1997-01-01

    A fuzzy adaptive feedforward control scheme in conjunction with classical feedback control is proposed for the low speed control of DC motors driving mechanical systems in the presence of friction. In the fuzzy adaptive scheme, a fuzzy logic based...

  6. AIAA-99-4227 RAPID ENERGY DISSIPATION IN A YO-YO-TYPE WIRE BOOM DEPLOYMENT SYSTEM

    E-print Network

    Psiaki, Mark L.

    AIAA-99-4227 RAPID ENERGY DISSIPATION IN A YO-YO-TYPE WIRE BOOM DEPLOYMENT SYSTEM by Mark L. Psiaki A wire boom deployment system has been developed that uses a mechanism which is similar to the classic yo-yo sounding-rocket experiment. The main challenge in using a yo-yo-type mechanism is to dissipate the excess

  7. Magnetic Properties and Large Barkhausen Effect of FeCo, FeCr, FeNi System Amorphous Wires

    Microsoft Academic Search

    Y. Konno; K. Kawashima; K. Mohri; M. Mizutani; K. Kimma; I. Ogasawara; H. Takamido

    1990-01-01

    Fe-rich and Co-rich amorphous magnetostrictive wires have shown sensitive bistable flux reversal (large Barkhausen effect or re-entrant flux reversal) characteristics. Fe-Co, Fe-Cr and Fe-Ni system amorphous wires were prepared, and their various magnetic properties (Ms, Mr\\/Ms, Ku, ¿s, H*, and ¿sMs\\/Ku) were measured to investigate the general properties of the large Barkhausen effect and stress sensitivity of such amorphous wire.

  8. Mitigation against overvoltages on a DC marine electrical system

    Microsoft Academic Search

    S. D. A. Fletcher; P. J. Norman; S. J. Galloway; G. M. Burt

    2009-01-01

    This paper analyzes the behavior of a highly capacitive DC marine network under fault conditions and demonstrates how overvoltages can be caused by the redistribution of stored energy following the clearance of a fault. This energy flow can be complex in nature, making it particularly difficult to sufficiently protect the network effectively. Through the analysis and simulation of a representative

  9. Secondary particle acquisition system for the CERN beam wire scanners upgrade

    NASA Astrophysics Data System (ADS)

    Sirvent, J. L.; Dehning, B.; Emery, J.; Diéguez, A.

    2015-04-01

    The increasing requirements of CERN experiments make essential the upgrade of beam instrumentation in general, and high accuracy beam profile monitors in particular. The CERN Beam Instrumentation Group has been working during the last years on the Wire Scanners upgrade. These systems cross a thin wire through a circulating beam, the resulting secondary particles produced from beam/wire interaction are detected to reconstruct the beam profile. For the new secondary shower acquisition system, it is necessary to perform very low noise measurements with high dynamic range coverage. The aim is to design a system without tuneable parameters and compatible for any beam wire scanner location at the CERN complex. Polycrystalline chemical vapour deposition diamond detectors (pCVD) are proposed as new detectors for this application because of their radiation hardness, fast response and linearity over a high dynamic range. For the detector readout, the acquisition electronics must be designed to exploit the detector capabilities and perform bunch by bunch measurements at 40MHz. This paper describes the design challenges of such a system, analysing different acquisition possibilities from the signal integrity point of view. The proposed system architecture is shown in detail and the development status presented.

  10. Safety considerations of aerial systems using insulated and covered wire and cable

    SciTech Connect

    Landinger, C.C.; McAuliffe, J.W. [Hendrix Wire and Cable, Milford, NH (United States)] [Hendrix Wire and Cable, Milford, NH (United States); Clapp, A.L.; Dagenhart, J.B. [Clapp Research Associates, Raleigh, NC (United States)] [Clapp Research Associates, Raleigh, NC (United States); Thue, W.A.

    1997-04-01

    Insulated and covered wires and cables have been used in aerial applications for over fifty years. Their various constructions, characteristics, and applications are discussed in Design and Application of Aerial Systems Using Insulated and Covered Wire and Cable. Some have suggested that covered wires and cables should be used in general applications solely for the purpose of providing safety to operating personnel and the general public. This paper discusses factors leading to the conclusion that nonshielded, covered conductor should not be installed solely to assure personal safety. The National Electrical Safety Code (NESC) treats covered conductors as bare conductors for purposes of clearances to personnel spaces; such a requirement is strongly supported by this paper.

  11. Point of collapse methods applied to AC\\/DC power systems

    Microsoft Academic Search

    C. A. Canizares; Fernando L. Alvarado; Christopher L. DeMarco; Ian Dobson; Willis F. Long

    1992-01-01

    The authors describe an extension of the point of collapse method developed for studies of AC systems to the determination of saddle-node bifurcations in power systems including high voltage direct current (HVDC) transmission. Bus voltage profiles are illustrated for an AC\\/DC test system. They significantly differ from the profiles of pure AC systems for typical system models. In particular, voltage

  12. Design considerations of a cable wiring system for a new medical center to support a future medical imaging system

    NASA Astrophysics Data System (ADS)

    Witt, Robert M.; Emrich, Jack

    1992-07-01

    Our Medical Center is faced with the problem to design a cable wiring system today, install it by the middle 1990''s, and allow for upgrades and enhancements for the next ten to fifteen years. The cable plant must be able to support functions and activities which are poorly defined today, but will include the hospital information system (HIS), a future picture archiving and communication system (PACS), and possibly an electronic patient chart with integrated image data. The cable plant must also connect to a future campus wide Medical Network of the Indiana University Medical center with the first component being a positron emission tomography system (PET) located approximately one mile away. To meet these goals the proposed cable plant will be a structured wire cabling system following existing and proposed standards for building wiring architectures including the Electronics Industries Association (EIA) and the Telecommunications Industries Association (TIA) 568 Commercial Building Wiring Standard and the proposed Federal Telecommunication Standard 1090. The structured wiring system approached has been evaluated with emphasis on the present and future network topologies that can be implemented, the type and size of fiber optic cable to install, and the need to install fiber optic cable to individual workstations.

  13. Radio frequency dc-dc power conversion

    E-print Network

    Rivas, Juan, 1976-

    2007-01-01

    THIS THESIS addresses the development of system architectures and circuit topologies for dc-dc power conversion at very high frequencies. The systems architectures that are developed are structured to overcome limitations ...

  14. Set Up and Test Results for a Vibrating Wire System for Quadrupole Fiducialization

    SciTech Connect

    Levashov, Michael Y.

    2010-12-01

    Quadrupoles will be placed between the undulator segments in LCLS to keep the electron beam focused as it passes through. The quadrupoles will be assembled with their respective undulator segments prior to being placed into the tunnel. Beam alignment will be used to center the quadrupoles, along with the corresponding undulators, on the beam. If there is any displacement between the undulator and the quadrupole axes in the assemblies, the beam will deviate from the undulator axis. If it deviates by more than 80{micro}m in vertical or 140{micro}m in horizontal directions, the undulator will not perform as required by LCLS. This error is divided between three sources: undulator axis fiducialization, quadrupole magnetic axis fiducialization, and assembly of the two parts. In particular, it was calculated that the quadrupole needs to be fiducialized to within 25{micro}m in both vertical and horizontal directions. A previous study suggested using a vibrating wire system for finding the magnetic axis of a quadrupole. The study showed that the method has high sensitivity (up to 1{micro}m) and laid out guidelines for constructing it. There are 3 steps in fiducializing the quadrupole with the vibrating wire system. They are positioning the wire at the magnet center (step 1), finding the wire with position detectors (step 2), and finding the quadrupole tooling ball positions relative to the position detector tooling balls (step 3). The following break up of error was suggested for the fiducialization steps: 10{micro}m for step 1 (finding the center), 20{micro}m for step 2 (finding the wire), and 10{micro}m for step 3 (tooling ball measurements). The purpose of this study is to investigate whether the vibrating wire system meets the requirements for LCLS. In particular, if it can reliably fiducialize a quadrupole magnetic center to within 25{micro}m in both vertical and horizontal directions. The behavior of individual system components is compared to the expected performance. A vibrating wire system was constructed to fiducialize the quadrupoles between undulator segments in the LCLS. This note studies the ability of the system to fulfill the fiducialization requirements.

  15. Set Up and Test Results for a Vibrating Wire System for Quadrupole Fiducialization

    SciTech Connect

    Not Available

    2010-11-29

    Quadrupoles will be placed between the undulator segments in LCLS to keep the electron beam focused as it passes through. The quadrupoles will be assembled with their respective undulator segments prior to being placed into the tunnel. Beam alignment will be used to center the quadrupoles, along with the corresponding undulators, on the beam. If there is any displacement between the undulator and the quadrupole axes in the assemblies, the beam will deviate from the undulator axis. If it deviates by more than 80{micro}m in vertical or 140{micro}m in horizontal directions, the undulator will not perform as required by LCLS. This error is divided between three sources: undulator axis fiducialization, quadrupole magnetic axis fiducialization, and assembly of the two parts. In particular, it was calculated that the quadrupole needs to be fiducialized to within 25{micro}m in both vertical and horizontal directions. A previous study suggested using a vibrating wire system for finding the magnetic axis of a quadrupole. The study showed that the method has high sensitivity (up to 1{micro}m) and laid out guidelines for constructing it. There are 3 steps in fiducializing the quadrupole with the vibrating wire system. They are positioning the wire at the magnet center (step 1), finding the wire with position detectors (step 2), and finding the quadrupole tooling ball positions relative to the position detector tooling balls (step 3). The following break up of error was suggested for the fiducialization steps: 10{micro}m for step 1 (finding the center), 20{micro}m for step 2 (finding the wire), and 10{micro}m for step 3 (tooling ball measurements). The purpose of this study is to investigate whether the vibrating wire system meets the requirements for LCLS. In particular, if it can reliably fiducialize a quadrupole magnetic center to within 25{micro}m in both vertical and horizontal directions. The behavior of individual system components is compared to the expected performance. A vibrating wire system was constructed to fiducialize the quadrupoles between undulator segments in the LCLS. This note studies the ability of the system to fulfill the fiducialization requirements.

  16. Evolution of the Design of a Second Generation FireWire Based Data Acquisition System

    PubMed Central

    Lewellen, T.K.; Miyaoka, R.S.; MacDonald, L.R.; Haselman, M.; DeWitt, D.; Hauck, S.

    2011-01-01

    Our laboratory has previously reported on the basic design concepts of an updated FireWire based data acquisition system for depth-of-interaction detector systems designed at the University of Washington. The new version of our data acquisition system leverages the capabilities of modern field programmable gate arrays (FPGA) and puts almost all functions into the FPGA, including the FireWire elements, the embedded processor, and pulse timing and integration. The design is centered around an acquisition node board (ANB) that includes 64 serial ADC channels, one high speed parallel ADC, FireWire 1394b support, the FPGA, a serial command bus and signal lines to support a rough coincidence window implementation to reject singles events from being sent on the FireWire bus. Adapter boards convert detector signals into differential paired signals to connect to the ANB. In this paper we discuss many of the design details, including steps taken to minimize the number of layers in the printed circuit board and to avoid skewing of parallel signals and unwanted bandwidth limitations. PMID:22228135

  17. Three-phase Four-wire Autonomous Wind Energy Conversion System Using Permanent Magnet Synchronous Generator

    Microsoft Academic Search

    Puneet K. Goel; Bhim Singh; S. S. Murthy; Shailendra K. Tiwari

    2010-01-01

    This article deals with an autonomous wind energy conversion system employing a permanent magnet synchronous generator feeding three-phase four-wire local loads in stand-alone mode without using a mechanical position sensor. The proposed autonomous wind energy conversion system utilizes two back-to-back connected pulse width modulated insulated gate bipolar transistors based voltage source converters with a battery energy storage system at their

  18. Investigation of transmission system voltage flicker due to multiple AC and DC furnace operations

    Microsoft Academic Search

    S. R. Mendis; M. T. Bishop; A. V. Do; D. M. Boyd

    1995-01-01

    This paper discusses an investigation of transmission system voltage flicker due to the effects of the operation of multiple AC and DC furnaces, harmonic filters, and static var systems. The utility transmission voltages are measured using a unique flicker measurement and evaluation system. The field tests are compared to an analysis of the expected flicker in the system.

  19. Application Studies of Immune PI Controller in Double Closed-Loop DC Speed Regulation System

    Microsoft Academic Search

    Wang Sue

    2010-01-01

    In accordance with the biological immune system regulating law and comparison the control system and the immune system, a parallel immune PI controller is proposed in this paper. Based on control requirements of double closed-loop DC speed regulating system and conventional control strategies, this paper presents that the control mode of applying immune PI control to speed loop and applying

  20. 77 FR 58424 - Drucker, Inc., DynaMotive Energy Systems Corp., and Gate to Wire Solutions, Inc., Order of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-20

    ...500-1] Drucker, Inc., DynaMotive Energy Systems Corp., and Gate to Wire Solutions, Inc., Order of Suspension of Trading September...current and accurate information concerning the securities of Gate to Wire Solutions, Inc. because it has not filed any...

  1. Department of Energy`s Wire Development Workshop - Superconductivity program for electric systems

    SciTech Connect

    NONE

    1996-06-01

    The 1996 High-Temperature Superconducting Wire Development Workshop was held on January 31--February 1 at the Crown Plaza Tampa Westshore in Tampa, Florida. The meeting was hosted by Tampa Electric Company and sponsored by the Department of Energy`s Superconductivity Program for Electric Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. Tampa Electric`s Greg Ramon began the meeting by giving a perspective on the changes now occurring in the utility sector. Major program wire development accomplishments during the past year were then highlighted, particularly the world record achievements at Los Alamos and Oak Ridge National Laboratories. The meeting then focussed on three priority technical issues: thallium conductors; AC losses in HTS conductors; and coated conductors on textured substrates. Following in-depth presentations, working groups were formed in each technology area to discuss and critique the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  2. Experimental Discussion on a 6-kW, 2-kWh Battery Energy Storage System Using a Bidirectional Isolated DC/DC Converter

    NASA Astrophysics Data System (ADS)

    Abe, Takahiro; Tan, Nadia Mei Lin; Akagi, Hirofumi

    This paper presents an experimental discussion on a 6-kW, full-bridge, zero-voltage switching bidirectional isolated dc/dc converter for a 53.2-V, 2-kWh Li-ion battery energy storage system. The combination of high-frequency switching devices, 600-V/200-A IGBTs and 100-V/500-A MOSFETs with a high-frequency transformer reduces the weight and physical size of the bidirectional isolated dc/dc converter. The dc voltage on the high-voltage side of the converter is controlled in a range of 300V to 355V as the battery voltage on the low-voltage side varies from 50V to 59V. Experimental verification of bidirectional power flow into (battery charging) or out of (battery discharging) the Li-ion battery bank is also presented. The maximal efficiency of the dc/dc converter is measured to be 98.1% during charging and 98.2% during discharging, excluding the gate drive loss and control circuit loss.

  3. DC-DC Converter for Avalanche Photodetector DC-DC converter to generate above 10 V from 2.5 V supply voltage.

    E-print Network

    Choi, Woo-Young

    Amplifier CDR Reverse Bias Voltage Boosting Circuit PWM Circuit Schematic Avalanche Photodetector SupplyDC-DC Converter for Avalanche Photodetector DC-DC converter to generate above 10 V from 2.5 V supply voltage. DC-DC Converter High-Speed Circuits and Systems Lab 1 DC-DC Converter TIA Limiting

  4. Design considerations for DC-DC converters in fuel cell systems 

    E-print Network

    Palma Fanjul, Leonardo Manuel

    2009-05-15

    to achieve a large voltage gain. Further a new modular fuel cell power converter system that divides the fuel cell stack to optimize power generation is proposed. It is shown by means of mathematical analysis and experimental prototypes that the proposed...

  5. A bidirectional DC-DC converter for fuel cell electric vehicle driving system

    Microsoft Academic Search

    Huang-Jen Chiu; Li-Wei Lin

    2006-01-01

    This paper presents a power converter for a fuel cell electric vehicle driving system. A new bidirectional, isolated topology is proposed in consideration of the differing fuel cell characteristics from traditional chemical-power battery and safety requirements. The studied converter has the advantages of high efficiency, simple circuit, and low cost. The detailed design and operating principles are analyzed and described.

  6. Voltage and power limitations of generation systems with uncontrolled PMSMs and DC\\/DC converters

    Microsoft Academic Search

    Zhu Lei; Wen Xuhui; Zhao Feng; Yao Yi

    2011-01-01

    Uncontrolled Generation (UCG) systems can be used in vehicles for their low cost and high reliability. This paper analyzes the output characteristics of UCG taking parameters and speed into consideration. New normalization method is used to simplify the analysis and the calculation. The voltage and power limitations are calculated in the normalized frame which is independent to the machine parameters.

  7. American Institute of Aeronautics and Astronautics Active System Identification of a DC-DC Converter Using

    E-print Network

    and potential fast algorithms are discussed for implementing the real-time converter regulation of external components, real-time programmability and integration with advanced features such as adaptive not disturb normal system operation in terms of static and dynamic voltage regulation, (b) the identification

  8. An Antilock-Braking Algorithm for an Eddy-Current-Based Brake-By-Wire System

    Microsoft Academic Search

    Sohel Anwar; Bing Zheng

    2007-01-01

    This paper presents a nonlinear sliding-mode-type controller for slip regulation in a braking event for an electromagnetic brake-by-wire (BBW)-system-equipped automobile. The electromagnetic BBW system under consideration consists of a set of eddy current brakes (ECBs) attached to the automobile wheels. The antilock-braking controller modifies the brake torque command generated by a supervisory controller which, in turn, is based on the

  9. Static state estimation of multiterminal DC/AC power system in rectangular co-ordinates

    SciTech Connect

    Roy, L.; Sinha, A.K. (Dept. of Electrical Engineering, IIT, Kharagpur 721 302 (IN)); Srivastava, H.N.P. (Dept. of Electrical Engineering, Bhagalpur College of Engineering (IN))

    1991-01-01

    This paper describes a simple, efficient and reliable method for estimating the state of an integrated multiterminal HVDC/AC power system in the rectangular coordinate form. A six variable model is used to represent the converter system. The proposed algorithm performs successfully in obtaining the state of an AC system with a DC link or a multiterminal DC network. It is possible to implement it for an on-line state estimation. Simulation results of a 30-busbar system are presented for illustration.

  10. Applying OMG D&C Specification and ECA Rules for Autonomous Distributed Component-based Systems

    E-print Network

    Paris-Sud XI, Université de

    Applying OMG D&C Specification and ECA Rules for Autonomous Distributed Component-based Systems J used to ease design of complex distributed systems. Nevertheless, at runtime, models remain useless, it is possible to de- sign both the distributed systems and their evolution poli- cies, and to execute them

  11. Modular DC-DC converter system for energy harvesting with EAPs

    NASA Astrophysics Data System (ADS)

    Eitzen, L.; Graf, C.; Maas, J.

    2013-04-01

    Energy harvesting with EAPs requires an energy-efficient power electronics providing a bidirectional energy transfer and operating voltages of up to several kilovolts. A possibility to achieve a high energy-efficiency for high voltage conversion is the use of a modular converter system consisting of several bidirectional converter modules, which are connected in series on the converter output side and in parallel at the input side. Since each converter stage provides only a part of the overall converter output voltage, the converter module output voltages can effectively be reduced by choosing the number of cascaded converter modules appropriately. This allows the use of standard semiconductor switches with superior electrical characteristics compared to high voltage semiconductors, enabling a high energy-efficiency and smaller passive components. Since EAP devices exhibit a mainly capacitive behavior and a limitation of the operating current is required for electrode protection, the utilized converter structure/topology has to be operated as a controllable current source on the lowest control level, which is achieved by operating the converter modules of the modular converter system with a subordinate closed-looped current control scheme. In order to avoid voltage unbalances among the single converter modules, a method for voltage balancing is presented. For validation, experimental results of a realized bidirectional flyback converter prototype are presented and discussed.

  12. L'Universit di Salerno ed il progetto D-CODE alla fiera di Hannover Il progetto europeo FP7 D-CODE (DC/DC Converter-based Diagnostics for PEM systems) coordinato dal

    E-print Network

    Costagliola, Gennaro

    -CODE (DC/DC Converter-based Diagnostics for PEM systems) ­ coordinato dal Dipartimento di Ingegneria celle a combustibile PEM. La principale innovazione del progetto D-CODE risiede nell'implementazione on

  13. Reliability of hybrid photovoltaic DC micro-grid systems for emergency shelters and other applications

    NASA Astrophysics Data System (ADS)

    Dhere, Neelkanth G.; Schleith, Susan

    2014-10-01

    Improvement of energy efficiency in the SunSmart Schools Emergency Shelters requires new methods for optimizing the energy consumption within the shelters. One major limitation in current systems is the requirement of converting direct current (DC) power generated from the PV array into alternating current (AC) power which is distributed throughout the shelters. Oftentimes, this AC power is then converted back to DC to run certain appliances throughout the shelters resulting in a significant waste of energy due to DC to AC and then again AC to DC conversion. This paper seeks to extract the maximum value out of PV systems by directly powering essential load components within the shelters that already run on DC power without the use of an inverter and above all to make the system reliable and durable. Furthermore, additional DC applications such as LED lighting, televisions, computers and fans operated with DC brushless motors will be installed as replacements to traditional devices in order to improve efficiency and reduce energy consumption. Cost of energy storage technologies continue to decline as new technologies scale up and new incentives are put in place. This will provide a cost effective way to stabilize the energy generation of a PV system as well as to provide continuous energy during night hours. It is planned to develop a pilot program of an integrated system that can provide uninterrupted DC power to essential base load appliances (heating, cooling, lighting, etc.) at the Florida Solar Energy Center (FSEC) command center for disaster management. PV arrays are proposed to be installed on energy efficient test houses at FSEC as well as at private homes having PV arrays where the owners volunteer to participate in the program. It is also planned to monitor the performance of the PV arrays and functioning of the appliances with the aim to improve their reliability and durability. After a successful demonstration of the hybrid DC microgrid based emergency shelter together with the monitoring system, it is planned to replicate it at other schools in Florida and elsewhere to provide continuous power for essential applications, maximizing the value of PV generation systems.

  14. High Efficiency Full Bridge Current-Fed DC-DC Converter for a Fuel Cell Power System

    Microsoft Academic Search

    O. A. Ahmed; J. A. M. Bleijs

    A new active clamp current-fed full bridge isolated DC-DC converter topology for fuel cell applications is presented. Comparison results show that this topology improves the efficiency over a wide load range. Using small signal analysis the AC equivalent circuit and transfer functions have been derived. These show that the dynamic response for the proposed converter is more benign than that

  15. Fatigue analysis of the taut-wire mooring system applied for deep waters

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Liu, Hai-Xiao; Shan, Gui-Min; Hu, Cun

    2011-09-01

    Precisely predicting the fatigue life of taut-wire mooring systems has become an interesting and important problem for scientists and engineers since there are still difficulties in the inspection and maintenance of mooring lines in a rough sea environment especially in deep waters. In this paper, a comprehensive fatigue analysis is performed for a polyester taut-wire mooring system of an FPSO based on the time domain dynamic theory, rainflow cycle counting method and linear damage accumulation rule of Palmgren-Miner. Three influential factors in the fatigue analysis including the pre-tension, dynamic stiffness and T-N curve are investigated in detail. Two polyester T-N curves, one is from the DNV-OS-E301 and the other is from the API-RP-2SM, are adopted in the calculation. The fatigue analysis of the mooring system after one-line failure is also carried out. The calculation results indicate that the fatigue life is significantly affected by the T-N curve. The fatigue life decreases with increasing pre-tension, and is largely reduced if taking into account the dynamic stiffness caused by cyclic loading. The analysis also proves that one-line failure has remarkable effects on the fatigue lives of other mooring lines. The present parametric and comparative study is believed to be meaningful to further understanding of the taut-wire mooring system for deepwater applications.

  16. Modeling of Steer-by-Wire System Used in New Braking Handwheel Concept

    NASA Astrophysics Data System (ADS)

    Messaoudène, K.; Oufroukh, N. Ait; Mammar, S.

    2008-06-01

    The handwheel is one of the primary control mechanisms of automobile thus interaction between the handwheel and the driver is critical to safety. The driver applies forces that direct the vehicle while the handwheel communicates feedback information to the driver of the forces experience by the car within its environment. The handwheel also provides a predictable mechanical feel to the driver to allow smooth and safe control. Many researchers tried to reproduce this feeling by creating steer-by-wire systems. This paper explores this new concept of handwheel and it describes the modeling steps of the components including the restitution mechanism for force feedback and its various links with the vehicle lateral dynamics and the pneumatic contacts. The aim is to explore the possibility to combine a braking device within the steer-by-wire system in order to provide a more suitable and ergonomic device to the driver.

  17. Comparative study of reference currents and DC bus voltage control for Three-Phase Four-Wire Four-Leg SAPF to compensate harmonics and reactive power with 3D SVM.

    PubMed

    Chebabhi, A; Fellah, M K; Kessal, A; Benkhoris, M F

    2015-07-01

    In this paper the performances of three reference currents and DC bus voltage control techniques for Three-Phase Four-Wire Four-Leg SAPF are compared for balanced and unbalanced load conditions. The main goals are to minimize the harmonics, reduce the magnitude of neutral current, eliminate the zero-sequence current components caused by single-phase nonlinear loads and compensate the reactive power, and on the other hand improve performances such as robustness, stabilization, trajectory pursuit, and reduce time response. The three techniques are analyzed mathematically and simulation results are compared. The techniques considered for comparative study are the PI Control, Sliding Mode Control and the Backstepping Control. Synchronous reference frame theory (SRF) in the dqo-axes is used to generate the reference currents, of the inverter. PMID:25704056

  18. Electrooptical measurement system for the DC characterization of visible detectors for CMOS-compatible vision chips

    Microsoft Academic Search

    Elisenda Roca; F. Frutos; S. Espejo; R. Dominguez-Castro; A. Rodnguez-Vgzquez

    1998-01-01

    An electrooptical measurement system for the dc characterization of visible detectors for CMOS-compatible vision chips is presented, which can help designers to characterize these detectors. The measurement system has been designed to be versatile, fast, and easily expandable and used. Two different setups for the measurement of the spectral response and the optical dynamic range of the detectors are described

  19. A universal DC characterisation system for hard and soft magnetic materials

    Microsoft Academic Search

    Philip Anderson

    2008-01-01

    A fully automatic system has been designed for the accurate measurement of the DC magnetic properties of soft and hard ferromagnetic materials utilising discrete calibrated instruments in order to provide a traceable calibration route separate from the transfer of standard magnetic test samples. Custom written software is used to operate the system in one of three modes, constant dH\\/dt, variable

  20. The optimization of PI controller parameters using genetic algorithm in the DC speed control system

    Microsoft Academic Search

    Jing Wang; Yuanyuan Zhao

    2000-01-01

    Given the change of characteristic parameters of the control object, deterioration will result in the dynamic response qualities of the main drive system of a hot finishing mill. This paper studies the optimization of PI parameters, which is adjusted by the improved iterative genetic algorithm, of the speed controller in a two-loop DC speed control system. The digital simulation results

  1. Implementation of LMP-FTR Mechanism in an AC-DC System

    Microsoft Academic Search

    V. Sarkar; S. A. Khaparde

    2008-01-01

    This paper analyzes the implementability of locational marginal price (LMP) and financial transmission right (FTR) mechanisms in the presence of high voltage DC (HVDC) lines in the regulated (i.e., under the control of system operator) network. The established framework of LMP-FTR mechanism assumes that the system under regulation is fully AC. Unregulated (or private) HVDC lines are taken into account

  2. The application of DC motor controller in the test system of intelligent elevator

    Microsoft Academic Search

    Jian Huang; Guo-jun Zhao; De-qiang Gu; Jun-hui Wang

    2011-01-01

    2 Abstract—this paper presents a test system of elevator model, in which ATmega128 Chip Microcontroller controller is used as the core control chip and the mode controlled by the Pulse Width Modulation technology. This system uses incremental optical encoder as speed detecting sensor, applies traditional PI digital controlling theories , and then produces PWM signal to drive the DC motor

  3. A Five-Phase Brushless DC-Machine Direct Drive System EPE Journal Vol. 14 no

    E-print Network

    Simões, Marcelo Godoy

    where an induction machine with asymmetric windings has three-phase sets advanced by 30 degreesA Five-Phase Brushless DC-Machine Direct Drive System EPE Journal Vol. 14 no 3 August 2004 15. Three-phase drive systems have been widely used for years because of the availability of such machines

  4. Design and construction evaluation of a photovoltaic DC LED lighting system

    Microsoft Academic Search

    Jyotsna Bhamidipati

    2008-01-01

    The market demand for commercialization of Photovoltaic (PV) systems depends a lot on the reliability, efficiency and performance of various components within the system. PV panels produce DC power when exposed to sunlight, and an inverter converts this to AC power in a typical solar powered building. Though, PV lighting has existed for a long time it hasn't been very

  5. Modified DSTATCOM Topology with Reduced DC Link Voltage for Reactive and Harmonic Power Compensation of Unbalanced Nonlinear Load in Distribution System

    NASA Astrophysics Data System (ADS)

    Geddada, Nagesh; Karanki, Srinivas B.; Mishra, Mahesh K.

    2014-06-01

    This paper proposes a modified four-leg distribution static compensator (DSTATCOM) topology for compensation of unbalanced and nonlinear loads in three-phase four-wire distribution system. DSTATCOM, connected in parallel to the load, supplies reactive and harmonic powers demanded by unbalanced nonlinear loads. In this proposed topology, the voltage source inverter (VSI) of DSTATCOM is connected to point of common coupling (point of interconnection of source, load, DSTATCOM) through interface inductor and series capacitance, unlike the conventional topology which consists of interface inductor alone. Load compensation with a lower value of input DC link voltage of VSI is possible in this modified topology compared to conventional topology. A comparative study on modified and conventional topologies in terms of voltage rating of inverter power switches, switching losses in VSI and power rating of input DC capacitor of VSI is presented. The detailed design aspects of DC link capacitor and interface series capacitor are also presented. The reference filter currents are generated using instantaneous symmetrical component theory and are tracked using hysteresis current control technique. A detailed simulation study is carried out, to compare the compensation performances of conventional, modified topologies using PSCAD simulator and experimental studies are done to validate the simulation results.

  6. Description of the SSF PMAD DC testbed control system data acquisition function

    NASA Technical Reports Server (NTRS)

    Baez, Anastacio N.; Mackin, Michael; Wright, Theodore

    1992-01-01

    The NASA LeRC in Cleveland, Ohio has completed the development and integration of a Power Management and Distribution (PMAD) DC Testbed. This testbed is a reduced scale representation of the end to end, sources to loads, Space Station Freedom Electrical Power System (SSF EPS). This unique facility is being used to demonstrate DC power generation and distribution, power management and control, and system operation techniques considered to be prime candidates for the Space Station Freedom. A key capability of the testbed is its ability to be configured to address system level issues in support of critical SSF program design milestones. Electrical power system control and operation issues like source control, source regulation, system fault protection, end-to-end system stability, health monitoring, resource allocation, and resource management are being evaluated in the testbed. The SSF EPS control functional allocation between on-board computers and ground based systems is evolving. Initially, ground based systems will perform the bulk of power system control and operation. The EPS control system is required to continuously monitor and determine the current state of the power system. The DC Testbed Control System consists of standard controllers arranged in a hierarchical and distributed architecture. These controllers provide all the monitoring and control functions for the DC Testbed Electrical Power System. Higher level controllers include the Power Management Controller, Load Management Controller, Operator Interface System, and a network of computer systems that perform some of the SSF Ground based Control Center Operation. The lower level controllers include Main Bus Switch Controllers and Photovoltaic Controllers. Power system status information is periodically provided to the higher level controllers to perform system control and operation. The data acquisition function of the control system is distributed among the various levels of the hierarchy. Data requirements are dictated by the control system algorithms being implemented at each level. A functional description of the various levels of the testbed control system architecture, the data acquisition function, and the status of its implementationis presented.

  7. A model-in-the-loop interface to emulate source dynamics in a zonal DC distribution system

    Microsoft Academic Search

    Weidong Zhu; Steve Pekarek; Juri Jatskevich; Oleg Wasynczuk; Dana Delisle

    2005-01-01

    A model-in-the-loop capability (MIL) has been developed to emulate the dynamics of alternative power sources in a hardware-based dc zonal electrical distribution system. Using this tool, models of the power sources are simulated in real-time and interfaced with hardware components at the voltage and current levels of the power system. Coupling between simulation and hardware is established through a dc\\/dc

  8. Wire Maze

    NSDL National Science Digital Library

    K-12 Outreach Office,

    Students gain a basic understanding of electrical circuits. They build wire circuits and pass paperclips through the mazes, trying not to touch the wires. Touching a wire with a paperclip causes the circuit to close, which activates an indicator.

  9. Wire Weight

    USGS Multimedia Gallery

    Wire weight is lowered to water surface to measure stage at a site. Levels are made to the wire weights elevation from known benchmarks to ensure correct readings. This wire weight is located along the Missouri River in Bismarck, ND....

  10. Can an AC (alternating current) electrical system replace the present DC system in the automobile? An investigative feasibility study. I. System architecture

    Microsoft Academic Search

    M. Abul Masrur; Daryl S. Sitar; V. A. Sankaran

    1998-01-01

    In the aerospace industry, the 400-Hz AC system replaced the DC system, and the latest trend in aerospace industry involves a combination of mixed AC and DC electrical system applications. With more and more equipment in the newer automobiles and a corresponding increase in power requirement, it is anticipated that in the not too distant future higher voltage and\\/or some

  11. DC brushless motor and ITS driving control system

    SciTech Connect

    Hagino, H.; Kotake, E.; Nakamura, K.

    1984-03-06

    A direct current brushless motor is structured by fixing a ring-shape magnetic rotor to a rotor shaft in one piece by way of the magnet yoke, and by arranging the position of the insulating plate on which the magnetic induction elements for detecting the magnetic field of the rotor magnet, stator windings and the rotor yoke are installed, so as to have the rotor magnet oppose the stator windings across an air gap. The stator windings are composed of delta connection wirings and the windings of each phase are placed on a concentric circle having the rotor shaft at its center and in a position dividing the said circle in equiangular areas. The magnetic induction elements are provided in three with the first, second and third elements being respectively fixed at the positions where their respective phases are advanced by ..pi../6 radian in the electric angle from the respective centers of the first phase, second phase and third phase coils. These magnetic induction elements pick up only the plus-side output signals and let the current flow respectively to the aforesaid three-phased stator windings through an amplifier, whereby they form a driving circuit for driving said rotor shaft.

  12. Wiring of Divergent Networks in the Central Auditory System

    PubMed Central

    Lee, Charles C.; Kishan, Amar U.; Winer, Jeffery A.

    2011-01-01

    Divergent axonal projections are found throughout the central auditory system. Here, we evaluate these branched projections in terms of their types, distribution, and putative physiological roles. In general, three patterns of axon collateralization are found: intricate local branching, long-distance collaterals, and branched axons (BAs) involved in feedback-control loops. Local collaterals in the auditory cortex may be involved in local processing and modulation of neuronal firing, while long-range collaterals are optimized for wide-dissemination of information. Rarely do axons branch to both ascending and descending targets. Branched projections to two or more widely separated nuclei or areas are numerically sparse but widespread. Finally, branching to contralateral targets is evident at multiple levels of the auditory pathway and may enhance binaural computations for sound localization. These patterns of axonal branching are comparable to those observed in other modalities. We conclude that the operations served by BAs are area- and nucleus-specific and may complement the divergent unbranched projections of local neuronal populations. PMID:21847372

  13. A Control Method of a Small-Scale DC Power System Including Distributed Generators

    NASA Astrophysics Data System (ADS)

    Ito, Youichi; Yang, Zhongqing; Akagi, Hirofumi

    This paper describes a dc micro-grid system interconnecting distributed power generators. The system consists of five generation and control units; a solar-cell generation unit, a wind-turbine generation unit, a battery energy-storage unit, a flywheel power-leveling unit, and an ac grid-interconnecting power control unit. The control method is proposed for suppressing the circulating current by detecting only the dc grid voltage. This method brings high reliability, high-flexibility and maintenance-free operation to the system. The method pays attention to dc output voltage performance of each unit. Each of the power control unit and the energy-storage unit is controlled to act as a voltage source with imaginery impedance. On the other hand, each of the two generation units is controlled to act as a current source. The power-leveling unit is controlled to act as a current source having the function of frequency selectivity like a high-pass filter. A 10-kW prototype system verifies experimentally the validity and effectiveness of the proposed control method for the dc-grid system.

  14. Texture development in Galfenol wire

    NASA Astrophysics Data System (ADS)

    Boesenberg, A. J.; Restorff, J. B.; Wun-Fogle, M.; Sailsbury, H.; Summers, E.

    2013-05-01

    Galfenol (Fe-Ga alloy) wire fabrication provides a low cost alternative to directional solidification methods. This work evaluates the compositional dependence of the wire drawing suitability of Fe-Ga and characterizes the microstructural and magnetic properties of these wires. Wire has been produced with Ga contents between 10 at. % and 17 at. % to allow determination of the ductile to brittle transition (DTBT) in wire manufacture. Published results on chill cast bend specimens indicated that a DTBT occurs at roughly 15 at. % Ga. This DTBT was observed under tensile loading with a corresponding change in fracture behavior from transverse fracture to intergranular fracture. For improved magnetostrictive performance, higher Ga contents are desired, closer to the 17 at. % Ga evaluated in this work. Electron backscattered diffraction B-H loop and resonance measurements as a function of magnetic field (to determine modulus and coupling factor) are presented for as-drawn, furnace, and direct current (DC) annealed wire. Galfenol wire produced via traditional drawing methods is found to have a strong <110> (?) texture parallel to the drawing direction. As-drawn wire was observed to have a lower magnetic permeability and larger hysteresis than DC annealed wire. This is attributed to the presence of a large volume of crystalline defects; such as vacancies and dislocations.

  15. Design of a high voltage input - output ratio dc-dc converter dedicated to small power fuel cell systems

    NASA Astrophysics Data System (ADS)

    Béthoux, O.; Cathelin, J.

    2010-12-01

    Consuming chemical energy, fuel cells produce simultaneously heat, water and useful electrical power [J.M. Andújar, F. Segura, Renew. Sust. Energy Rev. 13, 2309 (2009)], [J. Larminie, A. Dicks, Fuel Cell Systems Explained, 2nd edn. (John Wiley & Sons, 2003)]. As a matter of fact, the voltage generated by a fuel cell strongly depends on both the load power demand and the operating conditions. Besides, as a result of many design aspects, fuel cells are low voltage and high current electric generators. On the contrary, electric loads are commonly designed for small voltage swing and a high V/I ratio in order to minimize Joule losses. Therefore, electric loads supplied by fuel cells are typically fed by means of an intermediate power voltage regulator. The specifications of such a power converter are to be able to step up the input voltage with a high ratio (a ratio of 10 is a classic situation) and also to work with an excellent efficiency (in order to minimize its size, its weight and its losses) [A. Shahin, B. Huang, J.P. Martin, S. Pierfederici, B. Davat, Energy Conv. Manag. 51, 56 (2010)]. This paper deals with the design of this essential ancillary device. It intends to bring out the best structure for fulfilling this function. Several dc-dc converters with large voltage step-up ratios are introduced. A topology based on a coupled inductor or tapped inductor is closely studied. A detailed modelling is performed with the purpose of providing designing rules. This model is validated with both simulation and implementation. The experimental prototype is based on the following specifications: the fuel cell output voltage ranges from a 50 V open-voltage to a 25 V rated voltage while the load requires a constant 250 V voltage. The studied coupled inductor converter is compared with a classic boost converter commonly used in this voltage elevating application. Even though the voltage regulator faces severe FC specifications, the measured efficiency reaches 96% at the rated power whereas conventional boost efficiency barely achieves 91.5% in the same operating conditions.

  16. Design and construction evaluation of a photovoltaic DC LED lighting system

    NASA Astrophysics Data System (ADS)

    Bhamidipati, Jyotsna

    2008-08-01

    The market demand for commercialization of Photovoltaic (PV) systems depends a lot on the reliability, efficiency and performance of various components within the system. PV panels produce DC power when exposed to sunlight, and an inverter converts this to AC power in a typical solar powered building. Though, PV lighting has existed for a long time it hasn't been very effective, as incandescent light sources were commonly used which are inefficient. Today fluorescent fixtures are mostly used with PV's due to its high efficacy. Light-emitting diodes present a new vision to energy efficiency in lighting design with their low energy consumption. Current research predicts improved efficiencies of LED light fixtures and their commercial use is a few years away. LEDs which operate on DC voltages when coupled with photovoltaics can be a simple PV lighting application and a sustainable solution with potential for payback. This research evaluates the design and construction of a photovoltaic DC LED lighting system for a solar house at Pennsylvania State University. A detailed cost and payback analysis of a PV DC LED lighting system is presented in this research. PV output simulations for the solar house are presented. Results presented in this research indicate that the Solid state lighting market is evolving rapidly and that LED's are a choice in stand-alone photovoltaic DC lighting systems. The efficiency and the cost-effectiveness of such systems would however improve in the coming years with research and development now focused on PV systems and on Solid state lighting technologies.

  17. Transient Stability Analysis of Multi-Machine AC\\/DC Power Systems Via Energy-Function Method

    Microsoft Academic Search

    M. A. Pai; K. R. Padiyar; C. Radhakrishna

    1981-01-01

    In this paper, the direct method of stability analysis using energy functions is applied for single and multi-machine AC\\/DC power systems. The system loads including the terminal characteristics of the DC link are represented as constant current type loads, and their effects on the generators at the internal nodes are obtained as additional bus power injections using the method of

  18. EDA-Based Speed Control of a Networked DC Motor System With Time Delays and Packet Losses

    Microsoft Academic Search

    Hongbo Li; Mo-Yuen Chow; Zengqi Sun

    2009-01-01

    This paper presents a new controller design method for networked DC motor system in the presence of time delays and packet losses. The sufficient condition under which the closed-loop system is asymptotically stable and the necessary condition under which the networked DC motor has zero steady-state tracking error are derived. Based on the obtained conditions, an output tracking controller design

  19. Graphite electrode DC arc furnace system for treatment of environmentally undesirable solid waste

    Microsoft Academic Search

    C. H. Titus

    1993-01-01

    Summary form only given. A graphite electrode DC arc furnance system has been used to demonstrate that iron basalt soil containing various surrogate nonradioactive materials found on the Department of Energy's atomic energy sites and hospital waste can be reduced to a compact, vitrified, solid material which is environmentally acceptable and will pass TCLP leachate tests. A second graphite electrode

  20. Rotary Electrodynamics of a DC Motor: Motor as Mechanical Capacitor Lab 2: Modeling and System Identification

    E-print Network

    by the motor to its rotational output shaft. · m is the angular speed (i.e., derivative of the motor shaft to 85%). · is the angular speed (i.e., derivative of the load's angular position ) of the rotating conservation: im vm = m m Figure 1: Basic linear model for DC motor with inertial load. The system shown

  1. Evaluation of DC electric field measurement by the double probe system aboard the Geotail spacecraft

    NASA Astrophysics Data System (ADS)

    Kasaba, Y.; Hayakawa, H.; Ishisaka, K.; Okada, T.; Matsuoka, A.; Mukai, T.; Takei, Y.

    We summarize the characteristics of the DC electric field measurement by the double probe system, PANT and EFD-P, aboard Geotail. The accuracy and correction factors for the gain (effective length) and off-set, which depends on ambient plasma conditions are provided.

  2. A fast and flexible method for transient simulation of integrated AC\\/DC systems

    Microsoft Academic Search

    G. V. Giannakopoulos; N. A. Vovos; T. I. Maris; A. D. Lygdis

    1988-01-01

    The theoretical basis of a flexible and computationally efficient method for transient simulation of integrated AC\\/DC systems of any desired configuration is described. Using a modular modelling technique in conjunction with a modified state-variable approach, the state equations of the various components are formulated and solved separately at the expense of reduced computer storage and execution time. The method provides

  3. Software Development for a CompactRIO-Based Wire Scanner Control and Data Acquisition SYstem

    SciTech Connect

    Sedillo, James Daniel [Los Alamos National Laboratory

    2012-05-16

    The Beam Diagnostics and Instrumentation Team at the Los Alamos Neutron Science Center is developing a wire scanner data acquisition and control system with a National Instrument's compactRIO at its core. For this application, the compactRIO controller not only requires programming the FPGA and RT computer internal to the compactRIO, but also requires programming a client computer and a touch panel display. This article will summarize the hardware interfaces and describe the software design approach utilized for programming and interfacing the four systems together in order to fulfill the design requirements and promote reliable interoperability.

  4. Power system monitoring and source control of the Space Station Freedom DC power system testbed

    NASA Technical Reports Server (NTRS)

    Kimnach, Greg L.; Baez, Anastacio N.

    1992-01-01

    Unlike a terrestrial electric utility which can purchase power from a neighboring utility, the Space Station Freedom (SSF) has strictly limited energy resources; as a result, source control, system monitoring, system protection, and load management are essential to the safe and efficient operation of the SSF Electric Power System (EPS). These functions are being evaluated in the DC Power Management and Distribution (PMAD) Testbed which NASA LeRC has developed at the Power System Facility (PSF) located in Cleveland, Ohio. The testbed is an ideal platform to develop, integrate, and verify power system monitoring and control algorithms. State Estimation (SE) is a monitoring tool used extensively in terrestrial electric utilities to ensure safe power system operation. It uses redundant system information to calculate the actual state of the EPS, to isolate faulty sensors, to determine source operating points, to verify faults detected by subsidiary controllers, and to identify high impedance faults. Source control and monitoring safeguard the power generation and storage subsystems and ensure that the power system operates within safe limits while satisfying user demands with minimal interruptions. System monitoring functions, in coordination with hardware implemented schemes, provide for a complete fault protection system. The objective of this paper is to overview the development and integration of the state estimator and the source control algorithms.

  5. Power system monitoring and source control of the Space Station Freedom dc-power system testbed

    NASA Technical Reports Server (NTRS)

    Kimnach, Greg L.; Baez, Anastacio N.

    1992-01-01

    Unlike a terrestrial electric utility which can purchase power from a neighboring utility, the Space Station Freedom (SSF) has strictly limited energy resources; as a result, source control, system monitoring, system protection, and load management are essential to the safe and efficient operation of the SSF Electric Power System (EPS). These functions are being evaluated in the dc Power Management and Distribution (PMAD) Testbed which NASA LeRC has developed at the Power System Facility (PSF) located in Cleveland, Ohio. The testbed is an ideal platform to develop, integrate, and verify power system monitoring and control algorithms. State Estimation (SE) is a monitoring tool used extensively in terrestrial electric utilities to ensure safe power system operation. It uses redundant system information to calculate the actual state of the EPS, to isolate faulty sensors, to determine source operating points, to verify faults detected by subsidiary controllers, and to identify high impedance faults. Source control and monitoring safeguard the power generation and storage subsystems and ensure that the power system operates within safe limits while satisfying user demands with minimal interruptions. System monitoring functions, in coordination with hardware implemented schemes, provide for a complete fault protection system. The objective of this paper is to overview the development and integration of the state estimator and the source control algorithms.

  6. Speed control of a networked DC motor system with time delays and packet losses

    Microsoft Academic Search

    Hongbo Li; Mo-Yuen Chow; Zengqi Sun

    2008-01-01

    This paper presents a novel control methodology for networked DC motor speed control system. A discrete-time switch system is used to model the closed-loop system with time delays and packet losses, and the stability conditions are derived in terms of linear matrix inequalities (LMIs). Based on the obtained stability conditions, a two-step controller synthesis method is proposed. The first step

  7. A vector energy function approach for security analysis of AC\\/DC systems

    Microsoft Academic Search

    Christopher L. DeMarco; C. A. Canizares

    1992-01-01

    The authors examine dynamic behavior in system models that reflect reasonably detailed third-order high-voltage DC (HVDC) dynamics along with AC system models that include reactive flows, and frequency and voltage-dependent load models. A vector Lyapunov function approach is used to define a system-wide energy function that can be used for general security analysis. They describe the derivation of individual component

  8. A New Speed-Control System for DC Motors and its Application to Elevators

    Microsoft Academic Search

    Hiromi Inaba; Yoshimitsu Onoda; Seiya Shima; Takeki Ando; Toshiaki Kurosawa; Yoshio Sakai; Toshiaki Maekawa

    1980-01-01

    A circuit with a unidirectional armature current and bidirectional field current was used in order to realize a high-reliability speed-control system for dc motors by simplifying the armature circuit construction in comparison with conventional Thyristor-Leonard speed-control systems. In making the new circuit feasible, we developed a system in which either armature current or field current is fixed and the other

  9. The state-of-the-art of dc power distribution systems/components for space applications

    NASA Technical Reports Server (NTRS)

    Krauthamer, S.

    1988-01-01

    This report is a survey of the state of the art of high voltage dc systems and components. This information can be used for consideration of an alternative secondary distribution (120 Vdc) system for the Space Station. All HVdc components have been prototyped or developed for terrestrial, aircraft, and spacecraft applications, and are applicable for general space application with appropriate modification and qualification. HVdc systems offer a safe, reliable, low mass, high efficiency and low EMI alternative for Space Station secondary distribution.

  10. Sensor system for quality assurance in laser welding with filler wire

    NASA Astrophysics Data System (ADS)

    Kropla, Oliver

    1994-11-01

    This paper describes a system based upon an optical stereo sensor for measurement of the gap position and the joint gap width in laser welding. The measured width is used to control the filler wire speed. By means of sensor controlled filling of the missing material into the joint gap, manufacturing tolerances can be balanced and at an even seam quality, weld defects can be avoided. The sensor system is integrated into the work table control system thus allowing seam tracking based on the measured joint path. The stereo sensor consists of two lenses each featuring a plane deviating mirror by means of which the joining point is imaged upon each half of a CCD-line sensor. The image plane of the CCD-sensor and the principal plane of the lens system are running parallel and are positioned vertically towards the mirror surface thus avoiding distortions. In order to suppress plasma radiation which occurs during laser welding, the optics are shielded in the nearby infrared zone by means of a band-pass filter and the joining point is illuminated with a laser diode featuring a respective wavelength. A transputer net, coupled to the stereo camera and the wire feed system through a high-speed serial interface, serves the purpose of image interpretation and it shares a memory location with the work table control system for data exchange.

  11. Basic Wiring.

    ERIC Educational Resources Information Center

    Kaltwasser, Stan; And Others

    This module is the first in a series of three wiring publications; it serves as the foundation for students enrolled in a wiring program. It is a prerequisite to either "Residential Wiring" or "Commercial and Industrial Wiring." The module contains 16 instructional units that cover the following topics: occupational introduction; general safety;…

  12. Desicription and flight test results of the NASA F-8 digital fly-by-wire control system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A NASA program to develop digital fly-by-wire (DFBW) technology for aircraft applications is discussed. Phase I of the program demonstrated the feasibility of using a digital fly-by-wire system for aircraft control through developing and flight testing a single channel system, which used Apollo hardware, in an F-8C airplane. The objective of Phase II of the program is to establish a technology base for designing practical DFBW systems. It will involve developing and flight testing a triplex digital fly-by-wire system using state-of-the-art airborne computers, system hardware, software, and redundancy concepts. The papers included in this report describe the Phase I system and its development and present results from the flight program. Man-rated flight software and the effects of lightning on digital flight control systems are also discussed.

  13. LANSCE-R WIRE-SCANNER ANALOG FRONT-END ELECTRONICS

    SciTech Connect

    Gruchalla, Michael E. [Los Alamos National Laboratory

    2011-01-01

    A new AFE is being developed for the new LANSCE-R wire-scanner systems. The new AFE is implemented in a National Instruments Compact RIO (cRIO) module installed a BiRa 4U BiRIO cRIO chassis specifically designed to accommodate the cRIO crate and all the wire-scanner interface, control and motor-drive electronics. A single AFE module provides interface to both X and Y wire sensors using true DC coupled transimpedance amplifiers providing collection of the wire charge signals, real-time wire integrity verification using the normal dataacquisition system, and wire bias of 0V to +/-50V. The AFE system is designed to accommodate comparatively long macropulses (>1ms) with high PRF (>120Hz) without the need to provide timing signals. The basic AFE bandwidth is flat from true DC to 50kHz with a true first-order pole at 50kHz. Numeric integration in the cRIO FPGA provides real-time pulse-to-pulse numeric integration of the AFE signal to compute the total charge collected in each macropulse. This method of charge collection eliminates the need to provide synchronization signals to the wire-scanner AFE while providing the capability to accurately record the charge from long macropulses at high PRF.

  14. Optimal Design of Litz Wire Coils With Sandwich Structure Wirelessly Powering an Artificial Anal Sphincter System.

    PubMed

    Ke, Lei; Yan, Guozheng; Yan, Sheng; Wang, Zhiwu; Li, Xiaoyang

    2015-07-01

    Transcutaneous energy transfer system (TETS) is widely used to energize implantable biomedical devices. As a key part of the TETS, a pair of applicable coils with low losses, high unloaded Q factor, and strong coupling is required to realize an efficient TETS. This article presents an optimal design methodology of planar litz wire coils sandwiched between two ferrite substrates wirelessly powering a novel mechanical artificial anal sphincter system for treating severe fecal incontinence, with focus on the main parameters of the coils such as the wire diameter, number of turns, geometry, and the properties of the ferrite substrate. The theoretical basis of optimal power transfer efficiency in an inductive link was analyzed. A set of analytical expressions are outlined to calculate the winding resistance of a litz wire coil on ferrite substrate, taking into account eddy-current losses, including conduction losses and induction losses. Expressions that describe the geometrical dimension dependence of self- and mutual inductance are derived. The influence of ferrite substrate relative permeability and dimensions is also considered. We have used this foundation to devise an applicable coil design method that starts with a set of realistic constraints and ends with the optimal coil pair geometries. All theoretical predictions are verified with measurements using different types of fabricated coils. The results indicate that the analysis is useful for optimizing the geometry design of windings and the ferrite substrate in a sandwich structure as part of which, in addition to providing design insight, allows speeding up the system efficiency-optimizing design process. PMID:25808086

  15. Permanent Magnet DC Motor Sliding Mode Control System

    NASA Astrophysics Data System (ADS)

    Vaez-Zadeh, S.; Zamanian, M.

    2000-09-01

    In this paper a sliding mode controller (SMC) is designed for a permanent magnet, direct current (PMDC) motor to enhance the motor performance in the presence of unwanted uncertainties. Both the electrical and mechanical signals are used as the inputs to the SMC. The complete motor control system is simulated on a personal computer with different design parameters and desirable system performance is obtained. The experimental implementation of the motor control system is also presented. The test results confirm the simulation results and validate the proposed control system.

  16. Hybrid large scale system model for a DC microgrid

    Microsoft Academic Search

    P. Tulpule; S. Yurkovich; J. Wang; G. Rizzoni

    2011-01-01

    A microgrid power system with multiple energy sources and loads is considered in this paper. Such microgrids are common due to the needs of distributed generation, re- newable energy, and hybrid power sources. The system under study consists of a large number of power converters operating over a wide range of voltages and currents, interconnected via a distribution network. Stability

  17. Stray current characteristics of grounded, ungrounded, and diode grounded dc transit systems

    SciTech Connect

    Moody, K.J. [Parsons Brinckerhoff Quade and Douglas, Inc., Atlanta, GA (United States). Transportation Technologies Division

    1994-12-31

    The rapid increase of D.C. powered transit systems around the world has lead to the emergence of three distinct types of operational modes, i.e. grounded, ungrounded, and diode grounded. Each of these modes results in widely varying amounts of stray current in systems using the running rails for negative return current. This paper discusses the advantages of each operational mode and the possible stray current effects on transit and adjacent utility structures.

  18. Nonlinear control of mechatronic systems with permanent-magnet DC motors

    Microsoft Academic Search

    Sergey Edward Lyshevski

    1999-01-01

    The current trends in development and deployment of advanced electromechanical systems have facilitated the unified activities in the analysis and design of state-of-the-art motion devices, electric motors, power electronics, and digital controllers. This paper attacks the motion control problem (stabilization, tracking, and disturbance attenuation) for mechatronic systems which include permanent-magnet DC motors, power circuity, and motion controllers. By using an

  19. Proposed design of axial injection system for the DC-280 cyclotron

    NASA Astrophysics Data System (ADS)

    Gulbekian, G. G.; Gikal, B. N.; Bekhterev, V. V.; Bogomolov, S. L.; Efremov, A. A.; Ivanenko, I. A.; Kazarinov, N. Yu.; Kalagin, I. V.; Melnikov, V. N.; Osipov, N. F.; Prokhorov, S. V.; Tikhomirov, A. V.; Khabarov, M. V.

    2014-11-01

    The design of the high-voltage axial injection system for the DC-280 cyclotron that is being constructed at the Flerov Laboratory of Nuclear Reactions (FLNR) at the Joint Institute for Nuclear Research (JINR) is presented. The injection system will make it possible to efficiently inject ions of elements ranging from helium to uranium with the ratios of their atomic mass to the charge varying from 4 to 7.5.

  20. Mathematical model for the dc-ac inverter for the Space Shuttle

    NASA Technical Reports Server (NTRS)

    Berry, Frederick C.

    1987-01-01

    The reader is informed of what was done for the mathematical modeling of the dc-ac inverter for the Space Shuttle. The mathematical modeling of the dc-ac inverter is an essential element in the modeling of the electrical power distribution system of the Space Shuttle. The electrical power distribution system which is present on the Space Shuttle is made up to 3 strings each having a fuel cell which provides dc to those systems which require dc, and the inverters which convert the dc to ac for those elements which require ac. The inverters are units which are 2 wire structures for the main dc inputs and 2 wire structures for the ac output. When 3 are connected together a 4 wire wye connection results on the ac side. The method of modeling is performed by using a Least Squares curve fitting method. A computer program is presented for implementation of the model along with graphs and tables to demonstrate the accuracy of the model.

  1. Research study on multi-KW DC distribution system

    NASA Technical Reports Server (NTRS)

    Berkery, E. A.

    1975-01-01

    Power distribution system noise and transient stress on switchgear in large space vehicle power systems were investigated in terms of the effect of flight designs of long power distribution cables on load interface EMI requirements. A fifty meter cable pair was simulated to study interactions between the cable, load, and power source terminations. Power system noise characteristics were evaluated based on current spacecraft data, interface hardware filter designs, and power cable parameters. Parametric approaches were defined for evaluating switching transients at various distribution voltage levels. It is concluded that the state-of-the-art semiconductor switches represent a viable approach toward the implementation of power system design with distribution voltages of 120 VDC or less. The interface definition and design for the bus control unit was updated to be consistent with the established requirements.

  2. Annular suspension and pointing system with controlled DC electromagnets

    NASA Technical Reports Server (NTRS)

    Vu, Josephine Lynn; Tam, Kwok Hung

    1993-01-01

    The Annular Suspension and Pointing System (ASPS) developed by the Flight System division of Sperry Corporation is a six-degree of freedom payload pointing system designed for use with the space shuttle. This magnetic suspension and pointing system provides precise controlled pointing in six-degrees of freedom, isolation of payload-carrier disturbances, and end mount controlled pointing. Those are great advantages over the traditional mechanical joints for space applications. In this design, we first analyzed the assumed model of the single degree ASPS bearing actuator and obtained the plant dynamics equations. By linearizing the plant dynamics equations, we designed the cascade and feedback compensators such that a stable and satisfied result was obtained. The specified feedback compensator was computer simulated with the nonlinearized plant dynamics equations. The results indicated that an unstable output occurred. In other words, the designed feedback compensator failed. The failure of the design is due to the Taylor's series expansion not converging.

  3. Distributed image processing system for the monitoring of hot steel wire

    NASA Astrophysics Data System (ADS)

    O'Leary, Paul; Weiss, Michael; Schiller, Arnulf

    2003-05-01

    In a prototype for monitoring hot steel wire different technologies are integrated to achieve a robust, flexibly configurable and scalable imaging system. It is designed as a distributed system with private network and Tuplespace communication implementable on a LINUX Server. Intelligent cameras grab and process the image data. For real time communication between the cameras and standard industrial I/O-modules (IEC-61131) MODBUS/TCP messaging is applied. A switch with integrated firewall makes services available to the supervisory control system. Results are available as XML-logfiles. The image processing defines the upper and lower edges of the material by minimum/maximum filtering of the y-gradient. Dual Grassmanian coordinates are used to fit two parallel lines to the edge points by singular value decomposition. This gives the distance between the lines and the confidence interval of each measurement simultaneously, whereas latter is used to reject poor data. Changes of the distance are analysed computing local central moments. Presently, 12 images per second are acquired. The application is able to detect spontaneous rotation of the wire around the axis of rolling directly at the rolling stands and treats also poor images (due to steam of cooling water). It indicates resulting defects, which may go undetected otherwise.

  4. MIDAS, prototype Multivariate Interactive Digital Analysis System, phase 1. Volume 3: Wiring diagrams

    NASA Technical Reports Server (NTRS)

    Kriegler, F. J.; Christenson, D.; Gordon, M.; Kistler, R.; Lampert, S.; Marshall, R.; Mclaughlin, R.

    1974-01-01

    The Midas System is a third-generation, fast, multispectral recognition system able to keep pace with the large quantity and high rates of data acquisition from present and projected sensors. A principal objective of the MIDAS Program is to provide a system well interfaced with the human operator and thus to obtain large overall reductions in turn-around time and significant gains in throughput. The hardware and software generated in Phase I of the overall program are described. The system contains a mini-computer to control the various high-speed processing elements in the data path and a classifier which implements an all-digital prototype multivariate-Gaussian maximum likelihood decision algorithm operating at 2 x 100,000 pixels/sec. Sufficient hardware was developed to perform signature extraction from computer-compatible tapes, compute classifier coefficients, control the classifier operation, and diagnose operation. The MIDAS construction and wiring diagrams are given.

  5. A one-wire'' battery monitoring system with applications to on-board charging for electric vehicles

    SciTech Connect

    Nowak, D. (Alabama Univ., Huntsville, AL (USA). Kenneth E. Johnson Research Center)

    1990-10-08

    A novel on-board charge system which utilizes a One-Wire'' system for voltage monitoring is discussed and test results obtained using the system are presented. The system consists of a 20 kHz high frequency charger, an algorithm for charging lead-acid batteries with gelled electrolyte, such that gassing is avoided, the control system to implement this charge algorithm and a one-wire battery monitoring system to provide cell/module voltage information to the battery charge controller. Prototype elements of the system have been tested and the system was installed into an EVA Pacer electric vehicle. Charge tests are performed and data taken with the system installed. All elements of the system functioned properly under user conditions. In particular, the charger demonstrated good efficiency, near unity power factor and full programmability. The charge controller functioned reliably and without flaw. The one-wire monitoring system which permits monitoring of cell/module voltages in a battery pack without an extensive conventional wire harness has proven effective and voltage measurements have taken fast enough for control of charging. It was found that for the purpose of voltage monitoring under driving conditions, the system in its present form is too slow.

  6. Prospects of long-distance HTS DC power transmission systems

    NASA Astrophysics Data System (ADS)

    Romashov, M. A.; Sytnikov, V. E.; Shakarian, Y. G.; Ivanov, Y. V.

    2014-05-01

    Continual improvement of technologies for the safe use of power resources is a key to sustainable development of a human society. In particular, high-temperature superconductivity (HTS) should be used to meet the growing needs of the electric-power industry. It is known that HTS power cables allow us to increase the level of transmitted energy to several GW at voltage of 66-110 kV. HTS power cables of a coaxial design are almost ideal non-polluting system shielding electromagnetic field. In the present work we have tried to analyze various configurations of HTS power transmission systems, estimate the cable transmission capacitance depending on distance, and characterize reliability and efficiency of the systems.

  7. DC graphite arc furnace and diagnostic system for soils

    Microsoft Academic Search

    J. K. Wittle; C. H. Titus; R. A. Hamilton

    1994-01-01

    The need for systems to treat waste materials in a new manner has prompted the formation of an {open_quotes}Industry-National Laboratory-University{close_quotes} consortium to address the issue. The partners include Electro-Pyrolysis, Inc. (EPI), Massachusetts Institute of Technology (MIT), and Pacific Northwest Laboratory (PNL). The program includes technology transfer from industry to the national laboratory and university technology transfer to the national laboratory.

  8. Investigation of Microelectromechanical Switches for Next Generation DC Power Distribution System

    NASA Astrophysics Data System (ADS)

    Femi, R.; Clement, Shibu; Agrawal, Anita; Prince, A. Amalin

    2014-12-01

    This paper investigates the application of microelectromechanical system (MEMS) switches for DC power distribution system. Traditional electromechanical switches, solid state switches and solid state switch array are studied and simulated to understand their characteristics. Performance and characteristics of MEMS switches are reviewed and identified that electrostatically actuated MEMS switches are suitable for DC power applications. Scalable total cross tied (TCT) array configuration using MEMS switches has been proposed. The proposed configuration is suitable for variable voltage/current rating. Arc-less behavior of the switch configuration is analyzed using modified Paschen's curve. 400 V/6 A system is considered for the simulation and comparative study. The simulated result of the proposed MEMS switch array configuration is compared with the traditional switches. The comparative study shows that the proposed switch array configuration gives better performance in terms of voltage drop, leakage current, power loss, arc and size. This can be used in DC power system protection, circuit breaking, battery protection and smart grid load switching applications.

  9. A Numerical Method for Optimal Operating Problem of a Train Considering DC Power Feeding System

    NASA Astrophysics Data System (ADS)

    Ko, Hideyoshi; Miyatake, Masafumi

    An algorithm optimizing total energy consumption of a train operation considering DC feeding system is investigated in this paper. Our mathematical formulation consists of kinetic equation of a train and circuit equation of DC feeding system, and includes several characteristics of a train which depend on catenary voltage. It makes us possible to give more detailed consideration to energy-saving operation than that of previous works. Especially, it is remarkable aspect that several discussion about the effect of squeezing control of regenerating current and feeding loss have been possible with our proposed method. The optimizing algorithm is constructed based on the gradient method, which could be useful for the large-scale problem of future works with its light computer load and extensibility. Several numerical examples are demonstrated to verify the reliability and validity of the proposed method.

  10. A wire scanning based method for geometric calibration of high resolution CT system

    NASA Astrophysics Data System (ADS)

    Jiang, Ruijie; Li, Guang; Gu, Ning; Chen, Gong; Luo, Shouhua

    2015-03-01

    This paper is about geometric calibration of the high resolution CT (Computed Tomography) system. Geometric calibration refers to the estimation of a set of parameters that describe the geometry of the CT system. Such parameters are so important that a little error of them will degrade the reconstruction images seriously, so more accurate geometric parameters are needed in the higher-resolution CT systems. But conventional calibration methods are not accurate enough for the current high resolution CT system whose resolution can reach sub-micrometer or even tens of nanometers. In this paper, we propose a new calibration method which has higher accuracy and it is based on the optimization theory. The superiority of this method is that we build a new cost function which sets up a relationship between the geometrical parameters and the binary reconstruction image of a thin wire. When the geometrical parameters are accurate, the cost function reaches its maximum value. In the experiment, we scanned a thin wire as the calibration data and a thin bamboo stick as the validation data to verify the correctness of the proposed method. Comparing with the image reconstructed with the geometric parameters calculated by using the conventional calibration method, the image reconstructed with the parameters calculated by our method has less geometric artifacts, so it can verify that our method can get more accurate geometric calibration parameters. Although we calculated only one geometric parameter in this paper, the geometric artifacts are still eliminated significantly. And this method can be easily generalized to all the geometrical parameters calibration in fan-beam or cone-beam CT systems.

  11. Wire Maze

    NSDL National Science Digital Library

    Worcester Polytechnic Institute

    2013-01-01

    Learners create an electrical-circuit maze out of wire, then try to pass a paperclip through the maze without touching the wire. If the paper clip touches the wire, it closes the circuit, causing a light to come on or a buzzer to sound. This activity requires a basic understanding of how to build an electrical circuit.

  12. Flow gas transducer on basis of a hot wire with a nickel-titanium alloy in its flow calibration system

    Microsoft Academic Search

    C. A. Mugruza Vassallo; Catdica del Perti

    2001-01-01

    In our Latin American countries, little development has been carried out on medical control systems based on sensors (transducers) and actuators for our environment. This has motivated the present work. In medical applications such as breathing systems, hot wire flow sensors are already in use. Taking advantage of the sensor thermal convection, we can achieve a rapid operation using a

  13. Design and simulation of a wire position monitor for cryogenic systems in an ADS linac

    NASA Astrophysics Data System (ADS)

    Zhu, Hong-Yan; Dong, Lan; Li, Bo

    2014-08-01

    This paper introduces the design and simulation of a Wire Position Monitor (WPM) used in the cryogenic system of an Accelerator Driven System (ADS). The WPM is designed to monitor the contraction of cold masses during the cooling-down operation. In this paper, POISSON-2D electrostatic field software is used to calculate the best characteristic impedance for the WPM. Furthermore, the time domain signal of different end structures is theoretically analyzed and simulated. The coupling of electrodes and the influence of signal carrier size, which may influence the induced signal, are also discussed. Finally, the linearity of the induced voltage and the sensitivity of the WPM are analyzed. The time domain simulation results are consistent with the theoretical analysis. The influences of the coupling and carrier size are very small, and the linearity of the normalized voltage is good within r/2.

  14. Switching the Anomalous DC Response of an AC-driven Quantum Many-body system

    E-print Network

    Arnab Das; R. Moessner

    2012-08-01

    For a class of integrable quantum many-body systems, symmetric AC driving can generically produce a steady DC response. We show how such dynamical freezing can be switched off, not by forcing the system to follow the (arbitrarily fast) driving field, but rather through a much slower but complete oscillation of each individual mode of the system at a frequency of its own, with the slowest mode exhibiting a divergent period. This switching can be controlled in detail, its sharpness depending on a particular parameter of the Hamiltonian. The phenomenon has a robust manifestation even in the few-body limit, perhaps the most promising setting for realisation within existing frameworks.

  15. Hardware model of a shipboard zonal electrical distribution system (ZEDS) : alternating current/direct current (AC/DC)

    E-print Network

    Tidd, Chad N. (Chad Norman)

    2010-01-01

    A hardware model of a shipboard electrical distribution system based on aspects of the DDG 51 Flight IIA, Arleigh Burke class, 60Hz Alternating Current (AC) and the future direct current (DC), zonal electrical distribution ...

  16. Point of collapse methods applied to ac/dc power systems

    SciTech Connect

    Canizares, C.A.; Alvarado, F.L.; DeMarco, C.L.; Dobson, I.; Long, W.F. (Wisconsin Univ., Madison, WI (United States))

    1992-05-01

    This paper describes an extension of the Point of Collapse method developed for ac systems studies to the determination of saddle-node bifurcations in power systems including high voltage direct current (HVDC) transmission. Bus voltage profiles are illustrated for an ac/dc test system, which significantly differ from the profiles of pure ac systems for typical system models. In particular, voltage dependent current order limits (VDCOLs) are shown to affect the voltage profiles (nose curves) and the loadability margin of the system. It is also shown that Hopf bifurcations, which are not possible in purely ac lossless systems with second-order generator models, become plausible when the dynamics for the HVDC system are included.

  17. An overview of power electronics applications in fuel cell systems: DC and AC converters.

    PubMed

    Ali, M S; Kamarudin, S K; Masdar, M S; Mohamed, A

    2014-01-01

    Power electronics and fuel cell technologies play an important role in the field of renewable energy. The demand for fuel cells will increase as fuel cells become the main power source for portable applications. In this application, a high-efficiency converter is an essential requirement and a key parameter of the overall system. This is because the size, cost, efficiency, and reliability of the overall system for portable applications primarily depend on the converter. Therefore, the selection of an appropriate converter topology is an important and fundamental aspect of designing a fuel cell system for portable applications as the converter alone plays a major role in determining the overall performance of the system. This paper presents a review of power electronics applications in fuel cell systems, which include various topology combinations of DC converters and AC inverters and which are primarily used in fuel cell systems for portable or stand-alone applications. This paper also reviews the switching techniques used in power conditioning for fuel cell systems. Finally, this paper addresses the current problem encountered with DC converters and AC inverter. PMID:25478581

  18. Final Results of the Protected Superficial Femoral Artery Trial Using the FilterWire EZ System

    SciTech Connect

    Mueller-Huelsbeck, Stefan, E-mail: muehue@diako.d [Academic Teaching Hospitals Flensburg, Department of Diagnostic and Interventional Radiology/Neuroradiology (Germany); Huemme, Tim H.; Philipp Schaefer, J.; Charalambous, Nikolas [University Hospitals Schleswig-Holstein-Campus Kiel, Department of Radiology (Germany); Paulsen, Friedrich [University of Erlangen-Nuernberg, Department of Anatomy II (Germany); Heller, Martin; Jahnke, Thomas [University Hospitals Schleswig-Holstein-Campus Kiel, Department of Radiology (Germany)

    2010-12-15

    The purpose of this study was to evaluate the safety and efficacy of debris-capture for distal protection using the FilterWire EZ Embolic Protection System (Boston Scientific, Mountain View, CA) with the additional aim to further define the incidence of distal embolization during superficial femoral artery (SFA) interventions. A prospective, single-centre registry was designed to evaluate the performance of the FilterWire EZ in capturing debris during standard SFA percutaneous intervention. The PRO-RATA study included 30 patients suitable for PTA (Fontaine IIb to III or Rutherford I to II classification). The primary end points were occurrence of distal embolization or decreased runoff, improvement in ankle-brachial index ankle-brachial index (ABI) after the procedure, and number of filters containing emboli. Secondary end points included major adverse events (i.e., procedure- or device-related death and/or clinical target lesion revascularisation), device delivery, deployment success, and incidence of embolic recovery (patients with device success exhibiting embolic protection in the filter). Procedural success was determined as {<=}30% residual stenosis with no worsening of distal runoff as determined on angiography. A total of 29 patients (age 66.2 {+-} 12 years; total no. of limbs = 30; total no. of lesions = 30) suitable for PTA were enrolled in the study between February 2007 and March 2008. There were 26 patients with claudication (Fontaine IIB) and 3 patients with stage IV peripheral vascular disease. In one patient, lesions in both legs were treated. No procedural or device-related complications occured. The average degree of stenosis was 86 {+-} 7%. Stenosis length ranged from 8 to 88 mm. The average degree of residual stenosis was 10 {+-} 10%. ABI improved from 0.56 {+-} 0.16 to 0.92 {+-} 0.19 (P < 0.05). No restenosis or dissection was seen at 1-month ultrasound follow-up. Macroscopic debris was found in 27 of 30 filters of all distal protection devices used in all 29 patients. Debris particle size ranged from 90 to 2000 {mu}m (1200 {+-} 640). Histological debris analysis showed platelets, erythrocytes, inflammatory cells, extracellular matrix, and cholesterol as being the major components of emboli. Additional immunochemistry showed no correlation between lesion morphology and debris components. The FilterWire EZ is easy and safe to handle. The system caused no complications. In all cases, macroscopic debris was captured. Using a distal protection device during femoropopliteal interventions has the potential to prevent migration of debris, which may be important for high-risk patients with limited distal runoff.

  19. Skip cycle modulation in switching DC-DC converter

    Microsoft Academic Search

    Ping Luo; Luyang Luo; Zhaoji Li; Jian Yang; Guangiv Chen

    2002-01-01

    A novel control mode named SCM (skip cycle modulation) in switching DC-DC converter is developed and analyzed in this paper. The principles and the characteristics of SCM are described. Compared with PWM and PFM control modes, the response speed of DC-DC converter under SCM control mode is faster, the efficiency of the system with low loads is higher, and the

  20. Stability of large DC power systems using switching converters, with application to the international space station

    NASA Technical Reports Server (NTRS)

    Manners, B.; Gholdston, E. W.; Karimi, K.; Lee, F. C.; Rajagopalan, J.; Panov, Y.

    1996-01-01

    As space direct current (dc) power systems continue to grow in size, switching power converters are playing an ever larger role in power conditioning and control. When designing a large dc system using power converters of this type, special attention must be placed on the electrical stability of the system and of the individual loads on the system. In the design of the electric power system (EPS) of the International Space Station (ISS), the National Aeronautics and Space Administration (NASA) and its contractor team led by Boeing Defense & Space Group has placed a great deal of emphasis on designing for system and load stability. To achieve this goal, the team has expended considerable effort deriving a dear concept on defining system stability in both a general sense and specifically with respect to the space station. The ISS power system presents numerous challenges with respect to system stability, such as high power, complex sources and undefined loads. To complicate these issues, source and load components have been designed in parallel by three major subcontractors (Boeing, Rocketdyne, and McDonnell Douglas) with interfaces to both sources and loads being designed in different countries (Russia, Japan, Canada, Europe, etc.). These issues, coupled with the program goal of limiting costs, have proven a significant challenge to the program. As a result, the program has derived an impedance specification approach for system stability. This approach is based on the significant relationship between source and load impedances and the effect of this relationship on system stability. This approach is limited in its applicability by the theoretical and practical limits on component designs as presented by each system segment. As a result, the overall approach to system stability implemented by the ISS program consists of specific hardware requirements coupled with extensive system analysis and hardware testing. Following this approach, the ISS program plans to begin construction of the world's largest orbiting power system in 1997.

  1. Magnification of starting torques of dc motors by maximum power point trackers in photovoltaic systems

    NASA Technical Reports Server (NTRS)

    Appelbaum, J.; Singer, S.

    1989-01-01

    A calculation of the starting torque ratio of permanent magnet, series, and shunt-excited dc motors powered by solar cell arrays is presented for two cases, i.e., with and without a maximum-power-point tracker (MPPT). Defining motor torque magnification by the ratio of the motor torque with an MPPT to the motor torque without an MPPT, a magnification of 3 for the permanent magnet motor and a magnification of 7 for both the series and shunt motors are obtained. The study also shows that all motor types are less sensitive to solar insolation variation in systems including MPPTs as compared to systems without MPPTs.

  2. Load converter interactions with the secondary system in the Space Station Freedom power management and distribution dc test bed

    NASA Technical Reports Server (NTRS)

    Lebron, Ramon C.

    1992-01-01

    The NASA LeRC in Cleveland, Ohio, is responsible for the design, development, and assembly of the Space Station Freedom (SSF) Electrical Power System (EPS). In order to identify and understand system level issues during the SSF program design and development phases, a system Power Management and Distribution (PMAD) dc test bed was assembled. Some of the objectives of this test bed facility are the evaluation of, system efficiency, power quality, system stability, and system protection and reconfiguration schemes. In order to provide a realistic operating scenario, dc Load Converter Units are used in the PMAD dc test bed to characterize the user interface with the power system. These units are dc to dc converters that provide the final system regulation before power is delivered to the load. This final regulation is required on the actual space station because the majority of user loads will require voltage levels different from the secondary bus voltage. This paper describes the testing of load converters in an end to end system environment (from solar array to loads) where their interactions and compatibility with other system components are considered. Some of the system effects of interest that are presented include load converters transient behavior interactions with protective current limiting switchgear, load converters ripple effects, and the effects of load converter constant power behavior with protective features such as foldback.

  3. Load converter interactions with the secondary system in the Space Station Freedom power management and distribution DC test bed

    NASA Technical Reports Server (NTRS)

    Lebron, Ramon C.

    1992-01-01

    The NASA LeRC in Cleveland, Ohio, is responsible for the design, development, and assembly of the Space Station Freedom (SSF) Electrical Power System (EPS). In order to identify and understand system level issues during the SSF Program design and development phases, a system Power Management and Distribution (PMAD) DC test bed was assembled. Some of the objectives of this test bed facility are the evaluation of, system efficiency, power quality, system stability, and system protection and reconfiguration schemes. In order to provide a realistic operating scenario, dc Load Converter Units are used in the PMAD dc test bed to characterize the user interface with the power system. These units are dc to dc converters that provide the final system regulation before power is delivered to the load. This final regulation is required on the actual space station because the majority of user loads will require voltage levels different from the secondary bus voltage. This paper describes the testing of load converters in an end to end system environment (from solar array to loads) where their interactions and compatibility with other system components are considered. Some of the system effects of interest that are presented include load converters transient behavior interactions with protective current limiting switchgear, load converters ripple effects, and the effects of load converter constant power behavior with protective features such as foldback.

  4. The Influence of Pd-Doped Au Wire Bonding on HAZ Microstructure and Looping Profile in Micro-Electromechanical Systems (MEMS) Packaging

    NASA Astrophysics Data System (ADS)

    Ismail, Roslina; Omar, Ghazali; Jalar, Azman; Majlis, Burhanuddin Yeop

    2015-05-01

    Wire bonding processes has been widely adopted in micro-electromechanical systems (MEMS) packaging especially in biomedical devices for the integration of components. In the first process sequence in wire bonding, the zone along the wire near the melted tips is called the heat-affected zone (HAZ). The HAZ plays an important factor that influenced the looping profiles of wire bonding process. This paper investigates the effect of dopants on microstructures in the HAZ. One precent palladium (Pd) was added to the as-drawn 4N gold wire and annealed at 600°C. The addition of Pd was able to moderate the grain growth in the HAZ by retarding the heat propagation to the wire. In the formation of the looping profile, the first bending point of the looping is highly associated with the length of the HAZ. The alloyed gold wire (2N gold) has a sharp angle at a distance of about 30 m from the neck of the wire with a measured bending radius of about 40 mm and bending angle of about 40° clockwise from vertical axis, while the 4N gold wire bends at a longer distance. It also shows that the HAZ for 4N gold is longer than 2N gold wire.

  5. The Influence of Pd-Doped Au Wire Bonding on HAZ Microstructure and Looping Profile in Micro-Electromechanical Systems (MEMS) Packaging

    NASA Astrophysics Data System (ADS)

    Ismail, Roslina; Omar, Ghazali; Jalar, Azman; Majlis, Burhanuddin Yeop

    2015-07-01

    Wire bonding processes has been widely adopted in micro-electromechanical systems (MEMS) packaging especially in biomedical devices for the integration of components. In the first process sequence in wire bonding, the zone along the wire near the melted tips is called the heat-affected zone (HAZ). The HAZ plays an important factor that influenced the looping profiles of wire bonding process. This paper investigates the effect of dopants on microstructures in the HAZ. One precent palladium (Pd) was added to the as-drawn 4N gold wire and annealed at 600°C. The addition of Pd was able to moderate the grain growth in the HAZ by retarding the heat propagation to the wire. In the formation of the looping profile, the first bending point of the looping is highly associated with the length of the HAZ. The alloyed gold wire (2N gold) has a sharp angle at a distance of about 30 m from the neck of the wire with a measured bending radius of about 40 mm and bending angle of about 40° clockwise from vertical axis, while the 4N gold wire bends at a longer distance. It also shows that the HAZ for 4N gold is longer than 2N gold wire.

  6. Cost Effective Open Geometry HTS MRI System amended to BSCCO 2212 Wire for High Field Magnets

    SciTech Connect

    Kennth Marken

    2006-08-11

    The original goal of this Phase II Superconductivity Partnership Initiative project was to build and operate a prototype Magnetic Resonance Imaging (MRI) system using high temperature superconductor (HTS) coils wound from continuously processed dip-coated BSCCO 2212 tape conductor. Using dip-coated tape, the plan was for MRI magnet coils to be wound to fit an established commercial open geometry, 0.2 Tesla permanent magnet system. New electronics and imaging software for a prototype higher field superconducting system would have added significantly to the cost. However, the use of the 0.2 T platform would allow the technical feasibility and the cost issues for HTS systems to be fully established. Also it would establish the energy efficiency and savings of HTS open MRI compared with resistive and permanent magnet systems. The commercial goal was an open geometry HTS MRI running at 0.5 T and 20 K. This low field open magnet was using resistive normal metal conductor and its heat loss was rather high around 15 kolwatts. It was expected that an HTS magnet would dissipate around 1 watt, significantly reduce power consumption. The SPI team assembled to achieve this goal was led by Oxford Instruments, Superconducting Technology (OST), who developed the method of producing commercial dip coated tape. Superconductive Components Inc. (SCI), a leading US supplier of HTS powders, supported the conductor optimization through powder optimization, scaling, and cost reduction. Oxford Magnet Technology (OMT), a joint venture between Oxford Instruments and Siemens and the world’s leading supplier of MRI magnet systems, was involved to design and build the HTS MRI magnet and cryogenics. Siemens Magnetic Resonance Division, a leading developer and supplier of complete MRI imaging systems, was expected to integrate the final system and perform imaging trials. The original MRI demonstration project was ended in July 2004 by mutual consent of Oxford Instruments and Siemens. Between the project start and that date a substantial shift in the MRI marketplace occurred, with rapid growth for systems at higher fields (1.5 T and above) and a consequent decline in the low field market (<1.0 T). While the project aim appeared technically attainable at that time, the conclusion was reached that the system and market economics do not warrant additional investment. The program was redirected to develop BSCCO 2212 multifilament wire development for high field superconducting magnets for NMR and other scientific research upon an agreement between DOE and Oxford Instruments, Superconducting Technology. The work t took place between September, 2004 and the project end in early 2006 was focused on 2212 multifilamentary wire. This report summarizes the technical achievements both in 2212 dip coated for an HTS MRI system and in BSCCO 2212 multifilamentary wire for high field magnets.

  7. Drive laser system for the DC-SRF photoinjector at Peking University

    E-print Network

    Wang, Zhiwen; Lin, Lin; Zhao, Gang; Quan, Shengwen; Liu, Kexin; Chen, Jiaer

    2015-01-01

    Photoinjectors are widely used for linear accelerators as electron sources to generate high-brightness electron beam. Drive laser, which determines the timing structure and quality of the electron beam, is a crucial device of photoinjector. A new drive laser system has been designed and constructed for the upgraded 3.5-cell DC-SRF photoinjector at Peking University. The drive laser system consists of a 1064 nm laser oscillator, a four- stage amplifier, the second and fourth harmonic generators, the optical system to transfer the UV pulses to the photocathode, and the synchronization system. The drive laser system has been successfully applied in the stable operation of DC-SRF photoinjector and its performance meets the requirements. 266 nm laser with an average power close to 1W can be delivered to illuminate the Cs2Te photocathode and the instability is less than 5% for long time operation. The design consideration for improving the UV laser quality, a detailed description of laser system, and its performanc...

  8. A First Look at Wired Sensor Networks for Video Surveillance Systems

    Microsoft Academic Search

    Vijay Chandramohan; Kenneth J. Christensen

    2002-01-01

    High-bandwidth sensor applications such as video surveillance give rise to the need for a wired sensor network (WSN). We show IEEE 1394b FireWire to be a suitable candidate for a shared-medium WSN. We also propose a hybrid location-centric routing protocol for future WSNs with store and forward nodes.

  9. Metallic Glass Wire Based Localization of Kinesin/Microtubule Bio-molecular Motility System

    NASA Astrophysics Data System (ADS)

    Kim, K.; Sikora, A.; Yaginuma, S.; Nakayama, K. S.; Nakazawa, H.; Umetsu, M.; Hwang, W.; Teizer, W.

    2014-03-01

    We report electrophoretic accumulation of microtubules along metallic glass (Pd42.5Cu30Ni7.5P20) wires free-standing in solution. Microtubules are dynamic cytoskeletal filaments. Kinesin is a cytoskeletal motor protein. Functions of these bio-molecules are central to various dynamic cellular processes. Functional artificial organization of bio-molecules is a prerequisite for transferring their native functions into device applications. Fluorescence microscopy at the individual-microtubule level reveals microtubules aligning along the wire axis during the electrophoretic migration. Casein-treated electrodes are effective for releasing trapped microtubules upon removal of the external field. Furthermore, we demonstrate gliding motion of microtubules on kinesin-treated metallic glass wires. The reversible manner in the local adsorption of microtubules, the flexibility of wire electrodes, and the compatibility between the wire electrode and the bio-molecules are beneficial for spatio-temporal manipulation of the motility machinery in 3 dimensions.

  10. Ensuring Wire Alignment for the New COMPASS Drift Chamber

    NASA Astrophysics Data System (ADS)

    Cromis, Megan; Compass Dc5 Team

    2014-09-01

    COMPASS is a fixed-target experiment at CERN investigating the internal structure of the proton. Polarized Drell-Yan measurements at COMPASS will explore how the quark orbital angular momentum contributes to the spin of the proton. To enable this measurement, several straw tube chambers need to be replaced due to long term wear. One of the replacement chambers, drift chamber DC5, is being built at Old Dominion University based on a prototype from UIUC and existing COMPASS drift chambers. DC5 consists of 4 wire planes with 513 wires (256 [20 ?m] sense wires and 257 [100 ?m] field wires alternating) and 4 wire planes at a 10 degree offset with 641 wires each. Each of these 4616 wires need to be aligned within either 100 ?m (sense wire) or 200 ?m (field wire) of the center of the solder pad to ensure the accuracy of the drift chamber. Problems that arose during stringing include initial alignment of the wire and efficient soldering techniques. Also, because the field wires charged at -1750 volts will be 4 mm from the sense wires, there should be no gaps or points in the solder to prevent arcing. This poster will discuss the alignment techniques, soldering methods, testing, and repair process for the wires. COMPASS is a fixed-target experiment at CERN investigating the internal structure of the proton. Polarized Drell-Yan measurements at COMPASS will explore how the quark orbital angular momentum contributes to the spin of the proton. To enable this measurement, several straw tube chambers need to be replaced due to long term wear. One of the replacement chambers, drift chamber DC5, is being built at Old Dominion University based on a prototype from UIUC and existing COMPASS drift chambers. DC5 consists of 4 wire planes with 513 wires (256 [20 ?m] sense wires and 257 [100 ?m] field wires alternating) and 4 wire planes at a 10 degree offset with 641 wires each. Each of these 4616 wires need to be aligned within either 100 ?m (sense wire) or 200 ?m (field wire) of the center of the solder pad to ensure the accuracy of the drift chamber. Problems that arose during stringing include initial alignment of the wire and efficient soldering techniques. Also, because the field wires charged at -1750 volts will be 4 mm from the sense wires, there should be no gaps or points in the solder to prevent arcing. This poster will discuss the alignment techniques, soldering methods, testing, and repair process for the wires. This research was supported in part by the DOE under Grant Number DE-FG03-94ER40860.

  11. Impact of quasi-dc currents on three-phase distribution transformer installations. Power Systems Technology Program

    SciTech Connect

    McConnell, B.W.; Barnes, P.R. [Oak Ridge National Lab., TN (United States); Tesche, F.M. [Tesche (F.M.), Dallas, TX (United States); Schafer, D.A. [Mission Research Corp., Albuquerque, NM (United States)

    1992-06-01

    This report summarizes a series of tests designed to determine the response of quasi-dc currents on three-phase power distribution transformers for electric power systems. In general, if the dc injection is limited to the primary side of a step-down transformer, significant harmonic distortion is noted and an increase in the reactive power demand results. For dc injection on the secondary (load) side of the step-down transformer the harmonic content at the secondary side is quite high and saturation occurs with a relatively low level of dc injection; however, the reactive power demand is significantly lower. These tests produced no apparent damage to the transformers. Transformer damage is dependent on the duration of the dc excitation, the level of the excitation, and on thermal characteristics of the transfer. The transformer response time is found to be much shorter than seen in power transformer tests at lower dc injection levels. This shorter response time suggests that the response time is strongly dependent on the injected current levels, and that higher levels of dc injection for shorter durations could produce very high reactive power demands and harmonic distortion within a few tenths of a second. The added reactive power load could result in the blowing of fuses on the primary side of the transformer for even moderate dc injection levels, and neutral currents are quite large under even low-level dc injection. This ``smoking neutral`` results in high-level harmonic injection into equipment via the neutral and in possible equipment failure.

  12. Investigations of some aspects of the spray process in a single wire arc plasma spray system using high speed camera.

    PubMed

    Tiwari, N; Sahasrabudhe, S N; Tak, A K; Barve, D N; Das, A K

    2012-02-01

    A high speed camera has been used to record and analyze the evolution as well as particle behavior in a single wire arc plasma spray torch. Commercially available systems (spray watch, DPV 2000, etc.) focus onto a small area in the spray jet. They are not designed for tracking a single particle from the torch to the substrate. Using high speed camera, individual particles were tracked and their velocities were measured at various distances from the spray torch. Particle velocity information at different distances from the nozzle of the torch is very important to decide correct substrate position for the good quality of coating. The analysis of the images has revealed the details of the process of arc attachment to wire, melting of the wire, and detachment of the molten mass from the tip. Images of the wire and the arc have been recorded for different wire feed rates, gas flow rates, and torch powers, to determine compatible wire feed rates. High speed imaging of particle trajectories has been used for particle velocity determination using time of flight method. It was observed that the ripple in the power supply of the torch leads to large variation of instantaneous power fed to the torch. This affects the velocity of the spray particles generated at different times within one cycle of the ripple. It is shown that the velocity of a spray particle depends on the instantaneous torch power at the time of its generation. This correlation was established by experimental evidence in this paper. Once the particles leave the plasma jet, their forward speeds were found to be more or less invariant beyond 40 mm up to 500 mm from the nozzle exit. PMID:22380128

  13. A fast and flexible method for transient simulation of integrated AC/DC systems

    SciTech Connect

    Giannakopoulos, G.; Vovos, N.A.; Maris, T.; Lygdis, A. (Power Systems Lab., Electrical Engineering Dept., School of Engineering, Univ. of Patras (GR))

    1988-11-01

    The theoretical basis of a flexible and computationally efficient method for transient simulation of integrated AC/DC systems of any desired configuration is described. Using a modular modelling technique in conjunction with a modified state-variable approach, the state equations of the various components are formulated and solved separately at the expense of less computer storage and execution time. The method provides an efficient solution to the problem of simulating nonlinear characteristics and topological changes, such as caused by convertor operation, faults or other switching actions. Computer results to test and validate the proposed simulation method are also presented.

  14. Cooling of the 200 m superconducting DC power transmission system at Chubu University

    NASA Astrophysics Data System (ADS)

    Watanabe, Hirofumi; Sun, Jian; Ivanov, Yury; Hamabe, Makoto; Kawahara, Toshio; Yamaguchi, Satarou

    The fourth cooling test of the superconducting DC power transmission system of Chubu University was conducted in August of 2011. The heat leak from the cryogenic pipe and the eect of reducing the outer pipe temperature were tested. The heat leak from the cryogenic pipe was improved relative to that recorded during the second cooling test performedintheprevious summer,a season similartothatin whichthe fourth cooling testwas conducted.Asigni?cant reduction of the outer pipe temperature was achieved by an infrared re?ective coating, and a reduction of the heat leak was observed.

  15. A COAXIAL TE011 CAVITY AND A SYSTEM TO MEASURE DC AND RF PROPERTIES OF SUPERCONDUCTORS

    SciTech Connect

    Gianluigi Ciovati; Peter Kneisel; Ganapati Myneni; Larry Turlington; Gary Slack; Michael Morrone; William Clemens; Richard Bundy; Thomas Elliott; Jayanta Mondal

    2008-01-23

    A coaxial niobium cavity has been designed and built where the center conductor consists of a removable sample. In addition, a system to measure properties such as magnetization, penetration depth, critical temperature and thermal conductivity on the same cylindrical sample has been designed and built. The purpose of this effort is to investigate possible correlations between DC and RF properties of superconductors. In this contribution, the design of the various components is discussed and the test results on a niobium sample obtained so far are presented.

  16. Earth to space dc to dc power transmission system utilizing a microwave beam as source of energy for electric propelled interorbital vehicles

    NASA Technical Reports Server (NTRS)

    Brown, W. C.

    1985-01-01

    The paper contributes to the credibility of an electric propelled interorbital transportation system by introducing a new low-mass source of continuous dc power for electric propulsion and illustrating how the source can be economically tied to an electric utility on earth by an electronically steered microwave beam. The new thin-film rectenna, which functions as the receiving end of an earth-to-space microwave power transmission system is described. It is easily fabricated, is over 80 percent efficient, has a specific mass of no more than 2 kilograms per kilowatt of continuous dc power output, and is well adapted for deployment in space. The paper then describes a complete system consisting of the interorbital vehicle and the microwave power transmission system that supplies it with power. A design scenario is used to obtain performance data from the system in terms of vehicle transfer times, payload fractions, and costs. Electric energy costs are found to be less than $1000 per kilogram of payload delivered to geosynchronous orbit from low-earth orbit.

  17. Langmuir probe measurements of low pressure, low voltage DC plasma system

    NASA Astrophysics Data System (ADS)

    Hagedorn, Michael Stanley

    1999-11-01

    A Langmuir probe was built and software was developed to control the probe via a lock-in amplifier and to aid in automated data gathering and analysis. The probe was installed in a low pressure, low voltage DC plasma system that is currently being used to grow polymerized organo-silicon films. The hypothesis is that in a low pressure, low voltage DC plasma system, the electron mean free path is long enough that collisions are rare and that the electron energies are low enough that upon collision, an electron can only cause single ionization to occur. This should result in an electron population with a well defined, narrow distribution in energy. If the electron energy distribution is narrow enough, it should be possible to measure the energy distributions of the electrons that were involved in collisions and thereby determine which ionizations (and hence what chemistries) are occurring in the plasma. The purpose of this research is to characterize the performance of the Langmuir probe and examine the probe's interaction with the plasma system. The probe will then be used to make measurements of a process plasma and test the hypothesis.

  18. Easy route to superhydrophobic copper-based wire-guided droplet microfluidic systems.

    PubMed

    Mumm, Florian; van Helvoort, Antonius T J; Sikorski, Pawel

    2009-09-22

    Droplet-based microfluidic systems are an expansion of the lab on a chip concept toward flexible, reconfigurable setups based on the modification and analysis of individual droplets. Superhydrophobic surfaces are one suitable candidate for the realization of droplet-based microfluidic systems as the high mobility of aqueous liquids on such surfaces offers possibilities to use novel or more efficient approaches to droplet movement. Here, copper-based superhydrophobic surfaces were produced either by the etching of polycrystalline copper samples along the grain boundaries using etchants common in the microelectronics industry, by electrodeposition of copper films with subsequent nanowire decoration based on thermal oxidization, or by a combination of both. The surfaces could be easily hydrophobized with thiol-modified fluorocarbons, after which the produced surfaces showed a water contact angle as high as 171 degrees +/- 2 degrees . As copper was chosen as the base material, established patterning techniques adopted from printed circuit board fabrication could be used to fabricate macrostructures on the surfaces with the intention to confine the droplets and, thus, to reduce the system's sensitivity to tilting and vibrations. A simple droplet-based microfluidic chip with inlets, outlets, sample storage, and mixing areas was produced. Wire guidance, a relatively new actuation method applicable to aqueous liquids on superhydrophobic surfaces, was applied to move the droplets. PMID:19681579

  19. Three dimensional finite element methods: Their role in the design of DC accelerator systems

    NASA Astrophysics Data System (ADS)

    Podaru, Nicolae C.; Gottdang, A.; Mous, D. J. W.

    2013-04-01

    High Voltage Engineering has designed, built and tested a 2 MV dual irradiation system that will be applied for radiation damage studies and ion beam material modification. The system consists of two independent accelerators which support simultaneous proton and electron irradiation (energy range 100 keV - 2 MeV) of target sizes of up to 300 × 300 mm2. Three dimensional finite element methods were used in the design of various parts of the system. The electrostatic solver was used to quantify essential parameters of the solid-state power supply generating the DC high voltage. The magnetostatic solver and ray tracing were used to optimize the electron/ion beam transport. Close agreement between design and measurements of the accelerator characteristics as well as beam performance indicate the usefulness of three dimensional finite element methods during accelerator system design.

  20. A Kalman filtering based control scheme for the improvement of dynamic performance of an AC/DC power system

    NASA Astrophysics Data System (ADS)

    Pecen, Recayi

    In this dissertation, two major accomplishments are achieved. First, the feasibility of a proposed Wyoming to California HVDC system having the ratings of 1000 MW, ±500 kV, 2 kA, 860 miles and 12-pulse bipolar lines is shown for exporting Wyoming's electrical power resources to the heavy loaded western states. The second and the main objective of this dissertation is the development of a Kalman filtering (KF) based control scheme applied to an ac/dc power system. It is shown that the use KF algorithm to estimate some of the system states and utilizing them in a proportional Integral (PI) controller which has a better performance for this specific control scheme have resulted in a better dynamic performance of the proposed system. A set of case studies has shown that the system dynamic performance is improved for most of the contingencies. Ac and dc noisy voltage and current measurements received from the simulated ac/dc power system are sent to the KF estimation algorithm. The noise-separated best estimates of measurable states are computed and sent to a PI controller-based current and firing angle control subsections in order to provide a set of optimum thyristor firing angles for both converter stations during and after contingencies until the normal operation is reached. To evaluate the dynamic performance of the system with the KF algorithm, the model is simulated by a well-known digital simulation package, Electromagnetic Transients DC Program (PSCAD/EMTDC) of Manitoba HVDC Research Center. To apply the KF algorithm, a general, linearized, state-space model of the proposed ac/dc system, appropriate for analyzing both the KF and the electromagnetics transients, is derived first. The derived model enables the representation of an ac power system with two ac sources and one HVDC line with a parallel ac line connecting the two systems. It is shown that system eigenvalues of the discretized system model for a normal operating point are inside the unit circle that enables a stable operation. It is also shown that the system is controllable and observable for that specific point. The severity of a three-phase short circuit in the proposed ac/dc system is greatly reduced due to the HVDC link. One of the aims of this dissertation was to show that the addition of a parallel dc tie into an existing ac line resulted in dynamic performance improvement of the entire ac system, particularly during and after contingencies. It is also shown that a combination of the KF algorithm and PI control provides a stable recovery of the ac/dc system after a set of contingencies.

  1. Feasibility study of a 270V dc flat cable aircraft electrical power distributed system

    NASA Astrophysics Data System (ADS)

    Musga, M. J.; Rinehart, R. J.

    1982-01-01

    This report documents the efforts of a one man-year feasibility study to evaluate the usage of flat conductors in place of conventional round wires for a 270 volt direct current aircraft power distribution system. This study consisted of designing electrically equivalent power distribution harnesses in flat conductor configurations for a currently operational military aircraft. Harness designs were established for installation in aircraft airframes which are: (1) All metal, or (2) All composite, or (3) a mixture of both. Flat cables have greater surface areas for heat transfer allowing higher current densities and therefore lighter weight conductors, than with round wires. Flat cables are less susceptible to electromagnetic effects. However, these positive factors are partially offset by installation and maintenance difficulties. This study concludes that the extent of these difficulties can be adequately limited with appropriate modification to present installation and maintenance practices. A comparative analysis of the flat and the round conductor power distribution harnesses was made for weight, cost, maintenance and reliability. The knowledge gained from the design and comparative analysis phases was used to generate design criteria for flat power cable harnesses and to identify and prioritize flat cable harness components and associated production tooling which require development.

  2. A new wire chamber front-end system, based on the ASD-8 B chip

    NASA Astrophysics Data System (ADS)

    Krüsemann, B. A. M.; Bassini, R.; Ellinghaus, F.; Frekers, D.; Hagemann, M.; Hannen, V. M.; von Heynitz, H.; Heyse, J.; Rakers, S.; Sohlbach, H.; Wörtche, H. J.

    1999-07-01

    The Focal-Plane Polarimeter (FPP) for the Big-Bite Spectrometer van den Berg (Nucl. Instr. and Meth. B 99 (1995) 637ff) at the KVI requires the read-out of four large-area MWPCs and two VDCs with 3872 wires in total. The EUROSUPERNOVA collaboration (SNOVA) developed a digital 16 channel preamplifier front-end board, housing two amplifier-shaper-discriminatorchips ASD-8 B. The main features of this board are a fast single-wire readout, a high integration density, a low power consumption and compatibility to common instrumentation standards. The board represents the first successfully running application of the ASD-8 for wire chamber readout.

  3. Modelling of a DC arc furnace for optimal integration with the supply system

    Microsoft Academic Search

    J. Bekker; P. H. Swart; C. F. Landy; D. A. Marshall

    1995-01-01

    DC are furnaces have gained increasing favour with steel makers all over the world. DC arc furnaces have advantages over their conventional AC counterparts because of their greater supply-friendly nature. Although DC are furnaces still generate flicker, the stochastic component in their harmonics arc reduced and their demands on the supply network are much more compatible with the supply than

  4. An Intelligent Warehouse Stock Management and Tracking System Based on Silicon Identification Technology and 1Wire Network Communication

    Microsoft Academic Search

    Kai-Xin Tee; Moi-Tin Chew; Serge Demidenko

    2011-01-01

    This paper presents a novel electronic system for stock control and container tracking in a storage warehouse environment. The system is based on the use of advanced electronic identification tags and 1-Wire communication tools. Each warehouse container is affixed with a small electronic ID tag (called iButton). The tag is an electronic chip housed in a durable 16mm button-shaped stainless

  5. Research on an X-ray non-destructive testing system for conveyer belt with steel wire ropes

    Microsoft Academic Search

    Ye Chunqing; Miao Changyun

    2010-01-01

    The thesis conducts a deep research on an X-ray non-destructive testing system for the conveyer belt with steel wire ropes, and proposes the detailed design program. By researching the image processing algorithm of the conveyer belt, the research realized the marginal check, joint elongation check and breakdown location. Meanwhile, a system software was developed by using the C#.NET programming design

  6. McDonnell Douglas Space Systems worker checks STS-46 TSS wiring at KSC O and C

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In the Kennedy Space Center (KSC) Operations and Checkout (O and C) Building, a McDonnell Douglas Space Systems technician Hugh Beins, wearing a clean suit, inspects a complex array of wiring for the Tethered Satellite System (TSS) scheduled to fly on STS-46 aboard Atlantis, Orbiter Vehicle (OV) 104. Other technicians work on the spacelab enhanced multiplexer/demultiplexer pallet (EMP) and support struts in the background.

  7. Architectural design and reliability analysis of a fail-operational brake-by-wire system from ISO 26262 perspectives

    Microsoft Academic Search

    Purnendu Sinha

    2011-01-01

    Next generation drive-by-wire automotive systems enabling autonomous driving will build on the fail-operational capabilities of electronics, control and software (ECS) architectural solutions. Developing such architectural designs that would meet dependability requirements and satisfy other system constraints is a challenging task and will possibly lead to a paradigm shift in automotive ECS architecture design and development activities. This aspect is becoming

  8. Towards plant wires.

    PubMed

    Adamatzky, Andrew

    2014-08-01

    In experimental laboratory studies we evaluate a possibility of making electrical wires from living plants. In scoping experiments we use lettuce seedlings as a prototype model of a plant wire. We approximate an electrical potential transfer function by applying direct current voltage to the lettuce seedlings and recording output voltage. We analyse oscillation frequencies of the output potential and assess noise immunity of the plant wires. Our findings will be used in future designs of self-growing wetware circuits and devices, and integration of plant-based electronic components into future and emergent bio-hybrid systems. PMID:24928068

  9. Performance analysis of radiation cooled dc transmission lines for high power space systems

    NASA Technical Reports Server (NTRS)

    Schwarze, G. E.

    1985-01-01

    As space power levels increase to meet mission objectives and also as the transmission distance between power source and load increases, the mass, volume, power loss, and operating voltage and temperature become important system design considerations. This analysis develops the dependence of the specific mass and percent power loss on hte power and voltage levels, transmission distance, operating temperature and conductor material properties. Only radiation cooling is considered since the transmission line is assumed to operate in a space environment. The results show that the limiting conditions for achieving low specific mass, percent power loss, and volume for a space-type dc transmission line are the permissible transmission voltage and operating temperature. Other means to achieve low specific mass include the judicious choice of conductor materials. The results of this analysis should be immediately applicable to power system trade-off studies including comparisons with ac transmission systems.

  10. Performance analysis of radiation cooled dc transmission lines for high power space systems

    NASA Technical Reports Server (NTRS)

    Schwarze, G. E.

    1985-01-01

    As space power levels increase to meet mission objectives and also as the transmission distance between power source and load increases, the mass, volume, power loss, and operating voltage and temperature become important system design considerations. This analysis develops the dependence of the specific mass and percent power loss on the power and voltage levels, transmission distance, operating temperature and conductor material properties. Only radiation cooling is considered since the transmission line is assumed to operate in a space environment. The results show that the limiting conditions for achieving low specific mass, percent power loss, and volume for a space-type dc transmission line are the permissible transmission voltage and operating temperature. Other means to achieve low specific mass include the judicious choice of conductor materials. The results of this analysis should be immediately applicable to power system trade-off studies including comparisons with ac transmission systems.

  11. DC conductivity and magnetic properties of piezoelectric-piezomagnetic composite system

    NASA Astrophysics Data System (ADS)

    Hemeda, O. M.; Tawfik, A.; A-Al-Sharif; Amer, M. A.; Kamal, B. M.; El Refaay, D. E.; Bououdina, M.

    2012-11-01

    A series of composites (1-x) (Ni0.8Zn0.2Fe2O4)+x (BaTiO3), where x=0%, 20%, 40%, 60%, 80% and 100% BT content, have been prepared by the standard ceramic technique, then sintered at 1200 °C for 8 h. X-ray diffraction analysis shows that the prepared composites consist of two phases, ferrimagnetic and ferroelectric. DC electrical resistivity, thermoelectric power, charge carriers concentration and charge carrier mobility have been studied at different temperatures. It was found that the DC electrical conductivity increases with increasing BT content. The values of the thermoelectric power were positive and negative for the composites indicating that there are two conduction mechanisms, hopping and band conduction, respectively. Using the values of DC electrical conductivity and thermoelectric power, the values of charge carrier mobility and the charge carrier concentration were calculated. Magnetic measurements (hysteresis loop and magnetic permeability) show that the magnetization decreases by increasing BT content. M-H loop of pure Ni0.6 Zn0.4 Fe2O4 composite indicates that it is paramagnetic at room temperature and that the magnetization is diluted by increasing the BT content in the composite system. The value of magnetoelectric coefficient for the composites decreases by increasing BT content for all the compositions except for 40% BT content, which may be due to the low resistivity of magnetic phase compared with the BT phase that causes a leakage of induced charges on the piezoelectric phase. Since both ferroelectric and magnetic phases preserve their basic properties in the bulk composite, the present BT-NZF composite are potential candidates for applications as pollution sensors and electromagnetic waves.

  12. A new generic family of saturable reactor-assisted soft-switching PWM DC-DC converters for high-power density distributed power systems

    Microsoft Academic Search

    M. Nakaoka; M. Michihira; S. Hamada; Y. Murakami

    1992-01-01

    A generic family of high power density DC-DC power converter topologies with high-frequency AC link and without transformer isolation link is described. A saturable reactor assisted (SRA) soft switching mode constant frequency pulse width modulation (PWM) technique efficiently operates at a zero voltage switching transition scheme. This kind of quasi-trapezoidal wave mode PWM DC-DC power converter incorporates a small saturable

  13. Active dc filter for HVDC systemA test installation in the Konti-Skan DC link at Lindome converter station

    Microsoft Academic Search

    Wenyan Zhang; G. Asplund; A. Aberg; U. Jonsson; O. Loeoef

    1993-01-01

    The purpose of introducing active dc filters is to meet the more and more stringent requirement from power utilities on limiting telephone interference caused by harmonic currents from HVdc transmission lines, without unnecessarily increasing the cost of HVdc stations. An active dc filter installed in the Konti-Skan HVdc link is described. The active dc filter is connected at the bottom

  14. Hysteresis model of shape memory alloy wire-based laminated rubber bearing under compression and unidirectional shear loadings

    NASA Astrophysics Data System (ADS)

    Hedayati Dezfuli, F.; Shahria Alam, M.

    2015-06-01

    Smart lead rubber bearings (LRBs), in which a shape memory alloy (SMA) is used in the form of wires, are a new generation of elastomeric isolators with improved performance in terms of recentering capability and energy dissipation capacity. It is of great interest to implement SMA wire-based lead rubber bearings (SMA-LRBs) in bridges; however, currently there is no appropriate hysteresis model for accurately simulating the behavior of such isolators. A constitutive model for SMA-LRBs is proposed in this study. An LRB is equipped with a double cross configuration of SMA wires (DC-SMAW) and subjected to compression and unidirectional shear loadings. Due to the complexity of the shear behavior of the SMA-LRB, a hysteresis model is developed for the DC-SMAWs and then combined with the bilinear kinematic hardening model, which is assumed for the LRB. Comparing the hysteretic response of decoupled systems with that of the SMA-LRB shows that the high recentering capability of the DC-SMAW model with zero residual deformation could noticeably reduce the residual deformation of the LRB. The developed constitutive model for DC-SMAWs is characterized by three stiffnesses when the shear strain exceeds a starting limit at which the SMA wires are activated due to phase transformation. An important point is that the shear hysteresis of the DC-SMAW model looks different from the flag-shaped hysteresis of the SMA because of the specific arrangement of wires and its effect on the resultant forces transferred from the wires to the rubber bearing.

  15. Design of a Hybrid (Wired/Wireless) Acquisition Data System for Monitoring of Cultural Heritage Physical Parameters in Smart Cities

    PubMed Central

    García Diego, Fernando-Juan; Esteban, Borja; Merello, Paloma

    2015-01-01

    Preventive conservation represents a working method and combination of techniques which helps in determining and controlling the deterioration process of cultural heritage in order to take the necessary actions before it occurs. It is acknowledged as important, both in terms of preserving and also reducing the cost of future conservation measures. Therefore, long-term monitoring of physical parameters influencing cultural heritage is necessary. In the context of Smart Cities, monitoring of cultural heritage is of interest in order to perform future comparative studies and load information into the cloud that will be useful for the conservation of other heritage sites. In this paper the development of an economical and appropriate acquisition data system combining wired and wireless communication, as well as third party hardware for increased versatility, is presented. The device allows monitoring a complex network of points with high sampling frequency, with wired sensors in a 1-wire bus and a wireless centralized system recording data for monitoring of physical parameters, as well as the future possibility of attaching an alarm system or sending data over the Internet. This has been possible with the development of three board’s designs and more than 5000 algorithm lines. System tests have shown an adequate system operation. PMID:25815447

  16. Design of a hybrid (wired/wireless) acquisition data system for monitoring of cultural heritage physical parameters in Smart Cities.

    PubMed

    García Diego, Fernando-Juan; Esteban, Borja; Merello, Paloma

    2015-01-01

    Preventive conservation represents a working method and combination of techniques which helps in determining and controlling the deterioration process of cultural heritage in order to take the necessary actions before it occurs. It is acknowledged as important, both in terms of preserving and also reducing the cost of future conservation measures. Therefore, long-term monitoring of physical parameters influencing cultural heritage is necessary. In the context of Smart Cities, monitoring of cultural heritage is of interest in order to perform future comparative studies and load information into the cloud that will be useful for the conservation of other heritage sites. In this paper the development of an economical and appropriate acquisition data system combining wired and wireless communication, as well as third party hardware for increased versatility, is presented. The device allows monitoring a complex network of points with high sampling frequency, with wired sensors in a 1-wire bus and a wireless centralized system recording data for monitoring of physical parameters, as well as the future possibility of attaching an alarm system or sending data over the Internet. This has been possible with the development of three board's designs and more than 5000 algorithm lines. System tests have shown an adequate system operation. PMID:25815447

  17. A study on DC hybrid three-phase fault current limiting interrupter for a power distribution system

    NASA Astrophysics Data System (ADS)

    Shao, Hongtian; Satoh, Tomoyuki; Yamaguchi, Mitsugi; Fukui, Satoshi; Ogawa, Jun; Satoh, Takao; Ishikawa, Hiroyuki

    2005-10-01

    For the purpose of protecting electric power system, many researches and developments of fault current limiters are being performed. The authors studied a dc hybrid three-phase fault current limiting interrupter (FCLI) composed of a superconducting reactor and an S/N transition element, connected in series each other. The dc hybrid type fault current limiting interrupter can limit a fault current by means of the inductance of high temperature superconducting (HTS) coil together with the normal transition of HTS bulk material (HTSB). In the case of an accident, the normal transition of the bulk material can be accelerated by the magnetic field of the HTS coil. In this paper, the dc hybrid type fault current limiting interrupter for 5.5 km long 6.6 kV-600 A power distribution system is analyzed, and performances of fault current limitation and interruption are confirmed. Moreover, a reclosing operation is discussed for this power distribution system.

  18. Electro-optical measurement system for the DC characterization of visible detectors for CMOS compatible CNN vision chips

    Microsoft Academic Search

    Elisenda Roca; Fabián Frutos; Servando Espejo; Rafael Domínguez-Castro; A. Rodriguez-Vazquez

    1998-01-01

    An electro-optical measurement system for the DC characterization of visible detectors for CMOS compatible CNN chips is presented which can help designers to characterize these detectors. The measurement system has been designed to be versatile, fast and easily expandable and used. Two different set-up's for the measurement of the spectral response and the optical dynamic range of the detectors are

  19. Guiding the Selection of Physical Experiments for the Validation of a Model Designed to Study Grounding in Dc Distribution Systems

    Microsoft Academic Search

    Diomar Infante

    2011-01-01

    The following work establishes a process for model validation and its application to the study of grounding in DC shipboard power systems. The aim of the thesis is to create a general procedure detailing how to appropriately select physical experiments that validate the simulation model under use. The procedure presented can be applied to any physical system. In the work

  20. Electromechanical modelling and control of a micro-wind generation system for isolated low power DC micro grids

    Microsoft Academic Search

    Alba Colet-Subirachs; Oriol Gomis-Bellmunt; Daniel Clos-Costa; G. Martin-Segura; Adrià Junyent Ferre; Laia Ferrer Marti

    2009-01-01

    This paper describes the modelling and control of a micro-wind generation system, based on an axial flux permanent magnet synchronous generator (PMSG), for isolated low power DC micro grids. The system consists of a micro-wind turbine including a furling tail, a PMSG, a three phase diode rectifier and a buck converter connected to a battery bank and a load. Furthermore,

  1. A Distributed Control Strategy Based on DC Bus Signaling for Modular Photovoltaic Generation Systems With Battery Energy Storage

    Microsoft Academic Search

    Kai Sun; Li Zhang; Yan Xing; Josep M. Guerrero

    2011-01-01

    Modular generation system, which consists of mod- ular power conditioning converters, is an effective solution to in- tegrate renewable energy sources with conventional utility grid to improve reliability and efficiency, especially for photovoltaic generation. A distributed control strategy based on improved dc bus signaling is proposed for a modular photovoltaic (PV) gener- ation system with battery energy storage elements. In

  2. An Analytical Design Method for a Regenerative Braking Control System for DC-electrified Railway Systems under Light Load Conditions

    NASA Astrophysics Data System (ADS)

    Saito, Tatsuhito; Kondo, Keiichiro; Koseki, Takafumi

    A DC-electrified railway system that is fed by diode rectifiers at a substation is unable to return the electric power to an AC grid. Accordingly, the braking cars have to restrict regenerative braking power when the power consumption of the powering cars is not sufficient. However, the characteristics of a DC-electrified railway system, including the powering cars, is not known, and a mathematical model for designing a controller has not been established yet. Hence, the object of this study is to obtain the mathematical model for an analytical design method of the regenerative braking control system. In the first part of this paper, the static characteristics of this system are presented to show the position of the equilibrium point. The linearization of this system at the equilibrium point is then performed to describe the dynamic characteristics of the system. An analytical design method is then proposed on the basis of these characteristics. The proposed design method is verified by experimental tests with a 1kW class miniature model, and numerical simulations.

  3. On the effectiveness of charged wire structures for reducing electron backscatter in system-generated EMP simulators

    Microsoft Academic Search

    S. H. Gurbaxani; D. E. Jones; F. M. Tesche

    1981-01-01

    Using symmetry conditions and conformal mapping techniques, the two-dimensional problem of potentials due to a periodic assembly of thin line charges is first solved. The three-dimensional problem obtained by placing one and two cross-wire meshes parallel to a ground plane are then analyzed for evaluating the effectiveness of such structures in trapping Compton electrons in the system-generated EMP simulators. The

  4. RF-SQUID to DC-SQUID upgrade of a 28-channel magnetoencephalography (MEG) system

    NASA Astrophysics Data System (ADS)

    Diekmann, V.; Jürgens, R.; Becker, W.; Elias, H.; Ludwig, W.; Vodel, W.

    1996-05-01

    A Dornier 28-channel magnetoencephalography (MEG) system equipped with RF-SQUIDs and control electronics made by CTF (Port Coquitlam, BC, Canada) was upgraded by replacing the RF-SQUIDs with DC-SQUIDs developed at the University of Jena, Germany. New preamplifiers were designed that emulate the function of the system's original RF amplifiers. This allowed the continuing use of the system's control electronics without any modification. Retaining these control devices was instrumental for preserving the system's unique ability to derive software-defined gradiometer measurements from its magnetometer signals, and also saved a considerable investment of control software tailored to the characteristics of these devices. The performance of the upgraded system compares favourably to that of other multichannel instruments; its software gradiometer channels typically attain an overall sensitivity of 0957-0233/7/5/017/img7 (an improvement by a factor of three over the original RF system) and suppress residual noise inside the shielded room by 40 to 60 dB. Also described are the procedures used to calibrate the system, to eliminate crosstalk between neighbouring channels, and to determine the coefficients for optimum suppression of ambient noise by the software gradiometer.

  5. Wire Wise.

    ERIC Educational Resources Information Center

    Swanquist, Barry

    1998-01-01

    Discusses how today's technology is encouraging schools to invest in furnishings that are adaptable to computer use and telecommunications access. Explores issues concerning modularity, wiring management, ergonomics, durability, price, and aesthetics. (GR)

  6. Overview of wire bonding using copper wire or insulated wire

    Microsoft Academic Search

    Z. W. Zhong

    2011-01-01

    Wire bonding using copper or insulated wire leads to many advantages and new challenges. Research is intensively performed worldwide, leading to many new findings and solutions. This article reviews recent advances in wire bonding using copper wire or insulated wire for advanced microelectronics packaging. Journal articles, conference articles and patents published or issued recently are reviewed. The benefits and problems\\/challenges

  7. Estimation of Bidirectional Buck\\/boost DC\\/DC Converters with Electric Double-Layer Capacitors for Energy Storage Systems

    Microsoft Academic Search

    Shigeyuki Funabiki; Masayoshi Yamamoto

    2009-01-01

    Renewable energy such as wind force and solar light has collected the attention as alternative energy sources of fossil fuel. An energy storage system with an electric double-layer capacitor (EDLC), which balances the demand and supply power, is required in order to introduce the electric power generating system that utilizes renewable energy. Currently, the research and development of these energy

  8. An integrated digital PFM DC-DC boost converter for a power management application: a RGB backlight LED system driver

    Microsoft Academic Search

    P. L. Miribel-Catala; Manuel Puig-Vidal; J. Samitier i Marti; Phillipe Goyhenetche; Xuan-Quan Nguyen

    2002-01-01

    In this paper is presented a system that has been designed in the frame of a co-operation between the ON Semiconductor Microelectronics Company, at its Toulouse (France) Design Centre and the Electronics Department of the University of Barcelona (SIC Group). The system that has been designed is a high efficiency boost converter to supply and drive multicolour LEDs (light emitting

  9. Stretching Wires

    NSDL National Science Digital Library

    University of Illinois Urbana-Champaign

    2013-01-04

    In this activity, learners determine the elastic and plastic properties of different types of metal wires. Learners discover that wires of the same gauge, but made of different metals, typically support different loads (masses) before going through the elastic to plastic transition. Learners also learn the difference between elastic deformation, which is recoverable after the load is removed, and plastic deformation, which is not recoverable. Note: one way to save time on this lab is to have different groups test different metals.

  10. Working with Systems and Thinking Systemically--Disentangling the Crossed Wires

    ERIC Educational Resources Information Center

    Fox, Mark

    2009-01-01

    This article explores two separate traditions that educational psychologists (EPs) in the UK have for working with systems. One of these is "systems work" with organisations such as schools. The other is "systemic thinking" for working with families. Over the years these two traditions, systems work and systemic thinking, have become crossed and…

  11. DC electrostatic gyro suspension system for the Gravity Probe B experiment

    NASA Astrophysics Data System (ADS)

    Wu, Chang-Huei

    1994-12-01

    The Gravity Probe B experiment is a satellite-based experiment primarily designed to test two aspects of Einstein's General Theory of Relativity by observing the spin axis drift of near-perfect gyroscopes in a 650-km circular polar orbit. The goal of this experiment is to measure the drift angles to an accuracy of 0.3 milli-arcsec after one year in orbit. As a result, electrostatically suspended free-spinning gyroscopes operating at a very low temperature became the final choice for their ultra-low Newtonian torque-induced drift rate. The Conventional AC current-driven suspension system faces two fundamental difficulties for ground gyro testing. Field emission causes rotor charging and arcing with an imperfect electrode or rotor surfaces because the electric field intensity needed to support a solid rotor in the 1-g field is more than 107 V/m. The system not only becomes unstable at a high rotor charge, which can be more than 500 volts, but may also lose control in case of arcing. Both the high voltage AC suspension signal and the high frequency (1 MHz) signal for rotor position sensing interfere with the superconducting SQUID magnetometer for spin axis readout through inductive coupling. These problems were resolved by using DC voltage to generate a suspension force and a low frequency position sensor. In addition to the Input/Output linearization algorithm developed to remove the system nonlinearity for global stability and dynamic performance, we also minimized the electric field intensity to reduce rotor charging. Experimental results verified the desired global stability and satisfactory dynamic performance. The problem of rotor charging is virtually eliminated. More importantly, the DC system is compatible with the SQUID readout system in the Science Mission configuration. Consequently, experiments in low magnetic field at a sub-micro-gauss level for SQUID design verification and trapped flux distribution study were finally realizable in ground environment. The second part of the research focused on design issues for the Science Mission in a micro-g environment. The unique requirement of the GP-B experiment is to minimize suspension-induced torque and subsequent spin axis drift. A nonlinear control law which employs stiffened spring and stiffened damping coefficients was developed to achieve both low RMS noise in steady-state operation and quick response for situations like a micrometeoroid impact. Rotor voltage measurement and in-flight sensor bias correction schemes were developed to ensure system stability and absolute centering accuracy. Simulation results verified the system performances and confirmed that a suspension system induced rotor spin axis drift lower than 0.1 milli arcsec/year can be reached.

  12. Transient current pulses in rocket-extended wires used to trigger lightning

    NASA Astrophysics Data System (ADS)

    Biagi, C. J.; Uman, M. A.; Hill, J. D.; Rakov, V. A.; Jordan, D. M.

    2012-04-01

    We analyze current, electric field, and optical signatures of the sudden electrical breakdown processes (precursors) that occur at the top of the upward extending, grounded, Kevlar-covered copper wires used to artificially trigger lightning. For one launch, before the sustained upward positive leader initiated, we estimate that up to 10,000 precursors occurred (one every few hundred microseconds) with peak currents from 1 to more than 100 A. Luminosity at the wire tip was observed for 339 of 410 precursors examined in detail and, in seven cases, discharge channels developed to lengths of 3 to 8 m over times of several hundred microseconds. The measured propagation speeds of current pulses on the triggering wires were less than the speed of light, and decreased from about 2.8 × 108 m s-1 to about 2.3 × 108 m s-1with increasing wire-top heights from about 80 m to about 340 m. The triggering wire and its grounding system are modeled as uniform transmission lines with model predictions that are consistent with the measured wire-base precursor current signatures. The modeling shows that (1) the characteristic impedance of the triggering wire, the ratio of the propagating precursor voltage pulse to its associated current pulse, is between 600 and 800 ?; (2) the 25 m ground rod grounding impedance for the peak precursor current is about 100 ?, while the DC grounding resistance is 20 ?; and (3) the current reflection coefficient at ground for peak precursor current is ˜0.9.

  13. Preparation of high-quality hydrogenated amorphous silicon film with a new microwave electron cyclotron resonance chemical vapour deposition system assisted with hot wire

    Microsoft Academic Search

    Xiu-Hong Zhu; Guang-Hua Chen; Sheng-Yi Yin; Yan-Dong Rong; Wen-Li Zhang; Yue-Hui Hu

    2005-01-01

    The preparation of high-quality hydrogenated amorphous silicon (a-Si:H) film with a new microwave electron cyclotron resonance-chemical vapour deposition (MWECR-CVD) system assisted with hot wire is presented. In this system the hot wire plays an important role in perfecting the microstructure as well as improving the stability and the optoelectronic properties of the a-Si:H film. The experimental results indicate that in

  14. Arc fault detection scheme for 42-V automotive DC networks using current shunt

    Microsoft Academic Search

    Malakondaiah Naidu; Thomas J. Schoepf; Suresh Gopalakrishnan

    2006-01-01

    Introduction of higher dc system voltage distribution networks, such as the 42-V PowerNet in future passenger vehicles appears to be an unavoidable consequence of meeting the increasing future electrical power demand. Higher voltage electrical distribution networks in vehicles force considerable component and system changes regarding electrical safety and reliability. In the event of an arc fault, e.g., when a wire

  15. Performance analysis of a model-sized superconducting DC transmission system based VSC-HVDC transmission technologies using RTDS

    NASA Astrophysics Data System (ADS)

    Dinh, Minh-Chau; Ju, Chang-Hyeon; Kim, Sung-Kyu; Kim, Jin-Geun; Park, Minwon; Yu, In-Keun

    2012-08-01

    The combination of a high temperature superconducting DC power cable and a voltage source converter based HVDC (VSC-HVDC) creates a new option for transmitting power with multiple collection and distribution points for long distance and bulk power transmissions. It offers some greater advantages compared with HVAC or conventional HVDC transmission systems, and it is well suited for the grid integration of renewable energy sources in existing distribution or transmission systems. For this reason, a superconducting DC transmission system based HVDC transmission technologies is planned to be set up in the Jeju power system, Korea. Before applying this system to a real power system on Jeju Island, system analysis should be performed through a real time test. In this paper, a model-sized superconducting VSC-HVDC system, which consists of a small model-sized VSC-HVDC connected to a 2 m YBCO HTS DC model cable, is implemented. The authors have performed the real-time simulation method that incorporates the model-sized superconducting VSC-HVDC system into the simulated Jeju power system using Real Time Digital Simulator (RTDS). The performance analysis of the superconducting VSC-HVDC systems has been verified by the proposed test platform and the results were discussed in detail.

  16. Electrolyser in H2 Self-Producing Systems Connected to DC Link with Dedicated Phase Shift Converter

    Microsoft Academic Search

    C. Cavallaro; F. Chimento; S. Musumeci; C. Sapuppo; C. Santonocito

    2007-01-01

    In this paper the converter requirements for an optimum control of an electrolyser linked with a DC bus are analyzed and discussed. The hydrogen generating device is part of a complex system constituted by a supplying photovoltaic plant, the grid and a fuel cell battery. The characterization in several operative conditions of an actual industrial electrolyser is carried out in

  17. Direct Current Measurement Based Steer-By-Wire Systems for Realistic Driving Feeling

    E-print Network

    Ryu, Jee-Hwan

    the control design and simulation module in LabVIEW programming language. The simulated results show-by-wire development based on torque-map based method. This method is investigated with simulation results using Chang [2] described three experiments conducted in a driving simulator that explore how force feedback

  18. Power control of DC microgrid using DC bus signaling

    Microsoft Academic Search

    Li Zhang; Tianjin Wu; Yan Xing; Kai Sun; Josep. M Gurrero

    2011-01-01

    DC microgrid is an effective solution to integrate renewable energy sources with conventional utility grid, especially for photovoltaic generation. A DC microgrid configuration based on modular photovoltaic generation system and energy storage devices, which features good redundancy and high efficiency, is investigated in this paper. In order to optimize energy utilization, a power management scheme for DC microgrid is proposed,

  19. A new approach to dynamic analysis of ac networks incorporating detailed modeling of dc systems. Part II

    SciTech Connect

    Adapa, R. (Systems Engineering Dept., McGraw-Edison Power Systems, Cooper Industries, Inc., Canonsburg, PA (US)); Reeve, J. (Electrical Engineering Dept., Univ. of Waterloo, Waterloo, Ontario N2L 3G1 (CA))

    1988-10-01

    A new digital simulation concept which combines the detailed capability of the Electro-Magnetic Transients Program (EMTP) with the large system dynamic capability of a transient stability program (TSP) is applied to the study of interaction of a dc system with weak ac systems. The interface locations between the 2 simulations are extended to strategic points within the ac network. It is believed that greater predictability and authenticity of the response to disturbances have been achieved than hitherto.

  20. Foundational model of structural connectivity in the nervous system with a schema for wiring diagrams, connectome, and basic plan architecture

    PubMed Central

    Swanson, Larry W.; Bota, Mihail

    2010-01-01

    The nervous system is a biological computer integrating the body's reflex and voluntary environmental interactions (behavior) with a relatively constant internal state (homeostasis)—promoting survival of the individual and species. The wiring diagram of the nervous system's structural connectivity provides an obligatory foundational model for understanding functional localization at molecular, cellular, systems, and behavioral organization levels. This paper provides a high-level, downwardly extendible, conceptual framework—like a compass and map—for describing and exploring in neuroinformatics systems (such as our Brain Architecture Knowledge Management System) the structural architecture of the nervous system's basic wiring diagram. For this, the Foundational Model of Connectivity's universe of discourse is the structural architecture of nervous system connectivity in all animals at all resolutions, and the model includes two key elements—a set of basic principles and an internally consistent set of concepts (defined vocabulary of standard terms)—arranged in an explicitly defined schema (set of relationships between concepts) allowing automatic inferences. In addition, rules and procedures for creating and modifying the foundational model are considered. Controlled vocabularies with broad community support typically are managed by standing committees of experts that create and refine boundary conditions, and a set of rules that are available on the Web. PMID:21078980

  1. 49 CFR 234.239 - Tagging of wires and interference of wires or tags with signal apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...and interference of wires or tags with signal apparatus. 234.239 Section 234...DEPARTMENT OF TRANSPORTATION GRADE CROSSING SIGNAL SYSTEM SAFETY AND STATE ACTION PLANS...and interference of wires or tags with signal apparatus. Each wire shall be...

  2. 49 CFR 236.76 - Tagging of wires and interference of wires or tags with signal apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...and interference of wires or tags with signal apparatus. 236.76 Section 236...INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES...and interference of wires or tags with signal apparatus. Each wire shall be...

  3. 49 CFR 234.239 - Tagging of wires and interference of wires or tags with signal apparatus.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...and interference of wires or tags with signal apparatus. 234.239 Section 234...TRANSPORTATION GRADE CROSSING SAFETY, INCLUDING SIGNAL SYSTEMS, STATE ACTION PLANS, AND EMERGENCY...and interference of wires or tags with signal apparatus. Each wire shall be...

  4. 49 CFR 236.76 - Tagging of wires and interference of wires or tags with signal apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...and interference of wires or tags with signal apparatus. 236.76 Section 236...INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES...and interference of wires or tags with signal apparatus. Each wire shall be...

  5. 49 CFR 234.239 - Tagging of wires and interference of wires or tags with signal apparatus.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...and interference of wires or tags with signal apparatus. 234.239 Section 234...DEPARTMENT OF TRANSPORTATION GRADE CROSSING SIGNAL SYSTEM SAFETY AND STATE ACTION PLANS...and interference of wires or tags with signal apparatus. Each wire shall be...

  6. 49 CFR 236.76 - Tagging of wires and interference of wires or tags with signal apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...and interference of wires or tags with signal apparatus. 236.76 Section 236...INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES...and interference of wires or tags with signal apparatus. Each wire shall be...

  7. 49 CFR 236.76 - Tagging of wires and interference of wires or tags with signal apparatus.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...and interference of wires or tags with signal apparatus. 236.76 Section 236...INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES...and interference of wires or tags with signal apparatus. Each wire shall be...

  8. 49 CFR 234.239 - Tagging of wires and interference of wires or tags with signal apparatus.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...and interference of wires or tags with signal apparatus. 234.239 Section 234...TRANSPORTATION GRADE CROSSING SAFETY, INCLUDING SIGNAL SYSTEMS, STATE ACTION PLANS, AND EMERGENCY...and interference of wires or tags with signal apparatus. Each wire shall be...

  9. 49 CFR 234.239 - Tagging of wires and interference of wires or tags with signal apparatus.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...and interference of wires or tags with signal apparatus. 234.239 Section 234...TRANSPORTATION GRADE CROSSING SAFETY, INCLUDING SIGNAL SYSTEMS, STATE ACTION PLANS, AND EMERGENCY...and interference of wires or tags with signal apparatus. Each wire shall be...

  10. 49 CFR 236.76 - Tagging of wires and interference of wires or tags with signal apparatus.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...and interference of wires or tags with signal apparatus. 236.76 Section 236...INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES...and interference of wires or tags with signal apparatus. Each wire shall be...

  11. Extruded dielectric dc cable development. Final report

    SciTech Connect

    Kiersztyn, S.E.; MacKenzie, B.T.

    1980-04-01

    The development of an extruded 100-kilovolt (kV), direct-current (dc) cable insulated with mineral-filled polymeric dielectrics is described. Analysis of the factors controlling the rated stress and load limits indicated that capabilities of an extruded dc cable could be improved by reducing the dependency of electrical resistivity on temperature and the thermal resistivity of the dielectrics. It was experimentally determined that these two properties of extrudable polymers can be suitably modified by introduction of mineral fillers. Insulation efforts produced a family of candidate compounds exhibiting the desirable characteristics. Screening tests conducted on slab samples, insulated wires, and full-size experimental cables resulted in selecting a mineral-filled, cross-linked polyethylene compound, and a prototype 100-kV dc cable was manufactured. In addition to the the mineral-filled prototype, a reference cable insulated with conventional unfilled cross-linked polyethylene was made. Both cables were designed to meet the same operational requirements. The prototype and reference cables, connected in series, were subjected to the CIGRE dc cable qualification test, but failed it. However, the posttest examination disclosed multiple punctures in both cables, and it was not possible to conclude which cable initiated the failure of the series-connected cable system. The unfilled polyethylene reference cable was then retested alone and failed. Because of insufficient quantity of the original prototype, a mineral-filled, 35-kV ac cable from commercial production was selected as a substitute and subjected to and passed the CIGRE test. These results indicate that a mineral-filled, cross-linked polyethylene compound is a promising dielectric for extruded dc-power cable application.

  12. Novel Three-Component Rieske Non-Heme Iron Oxygenase System Catalyzing the N-Dealkylation of Chloroacetanilide Herbicides in Sphingomonads DC-6 and DC-2

    PubMed Central

    Chen, Qing; Wang, Cheng-Hong; Deng, Shi-Kai; Wu, Ya-Dong; Li, Yi; Yao, Li; Jiang, Jian-Dong; Yan, Xin; Li, Shun-Peng

    2014-01-01

    Sphingomonads DC-6 and DC-2 degrade the chloroacetanilide herbicides alachlor, acetochlor, and butachlor via N-dealkylation. In this study, we report a three-component Rieske non-heme iron oxygenase (RHO) system catalyzing the N-dealkylation of these herbicides. The oxygenase component gene cndA is located in a transposable element that is highly conserved in the two strains. CndA shares 24 to 42% amino acid sequence identities with the oxygenase components of some RHOs that catalyze N- or O-demethylation. Two putative [2Fe-2S] ferredoxin genes and one glutathione reductase (GR)-type reductase gene were retrieved from the genome of each strain. These genes were not located in the immediate vicinity of cndA. The four ferredoxins share 64 to 72% amino acid sequence identities to the ferredoxin component of dicamba O-demethylase (DMO), and the two reductases share 62 to 65% amino acid sequence identities to the reductase component of DMO. cndA, the four ferredoxin genes, and the two reductases genes were expressed in Escherichia coli, and the recombinant proteins were purified using Ni-affinity chromatography. The individual components or the components in pairs displayed no activity; the enzyme mixture showed N-dealkylase activities toward alachlor, acetochlor, and butachlor only when CndA-His6 was combined with one of the four ferredoxins and one of the two reductases, suggesting that the enzyme consists of three components, a homo-oligomer oxygenase, a [2Fe-2S] ferredoxin, and a GR-type reductase, and CndA has a low specificity for the electron transport component (ETC). The N-dealkylase utilizes NADH, but not NADPH, as the electron donor. PMID:24928877

  13. 46 CFR 111.60-11 - Wire.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...60-11 Section 111.60-11 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Wiring Materials and Methods § 111.60-11 Wire....

  14. DC Electric Field Measurement by the Double Probe System Aboard Geotail and its Simulation

    NASA Astrophysics Data System (ADS)

    Kasaba, Y.; Hayakawa, H.; Ishisaka, K.; Okada, T.; Matsuoka, A.; Mukai, T.; Okada, M.

    2005-12-01

    We summarize the characteristics of the DC electric field measurement by the double probe system, PANT and EFD-P, aboard Geotail. The accuracy and correction factors for the gain (effective length) and off-set, which depends on ambient plasma conditions, are provided. Accurate measurements of electric fields are essential for space plasma studies, for example, plasma convection, wave-particle interactions, violation of MHD approximation, etc. One typical measurement techniques is the 'Double Probe method', identical to that of a voltmeter: the potential difference between two top-hat probes [cf. Pedersen et al., 1984]. This method can measure electric fields passively and continuously in all plasma conditions. However, the accuracy of the measured electric field values is limited. The probe measurement is also subjected to the variable gain (effective length) of the probe antenna and the artificial offset of the measured values. Those depend on a) the disturbance from ambient plasma and b) the disturbance from the spacecraft and the probe itself. In this paper, we show the results of the characteristics of DC electric field measurement by the PANT probe and the EFD-P (Electric Field Detector - Probe technique) receiver aboard Geotail [Tsuruda et al., 1994], in order to evaluate the accuracy, gain, and offset controlled by ambient plasmas. We conclude that the Geotail electric field measurement by the double probe system has the accuracy 0.4 mV/m for Ex and 0.3 mV/m for Ey, after the correction of the gain and offset. In better conditions, accuracy of Ey is 0.2 mV/m. The potential accuracy would be better because those values are limited by the accuracy of the particle measurement especially in low density conditions. In practical use, the corrections by long-term variation and spacecraft potential are effective to refine the electric field data. The characteristics of long-term variation and the dependences on ambient plasma are not fully understood well, yet. Further works will be needed based on the calibrated LEP data after 1998. It will also cover the conditions rejected in this paper, i.e., low density regions, potential controlled period, electric field quasi-parallel to magnetic field, etc. The comparison with EFD-B (EFD - Beam technique) data will also be included in order to reject the ambiguity in particle observations. In addition, we are trying to establish the numerical model of the double probe system for the full-quantitative understanding of the effect of potential structure and photoelectron distributions. Those will be the basis for planned experiments, BepiColombo to Mercury, ERG to the inner magnetosphere, and the multi-spacecraft magnetospheric mission SCOPE.

  15. Locating Hidden Hazards in Electrical Wiring

    Microsoft Academic Search

    Paul K. Kuhn

    2006-01-01

    Hazardous electrical wiring has been identified as an area of critical national and international concern. Faulty and improperly installed electrical wiring is a leading cause of fires in homes and commercial buildings. Wiring is also responsible for numerous problems in consumer product safety, vehicular safety\\/reliability, safety of nuclear facilities, reliability of power distribution systems, reliability of communication systems, and others.

  16. Wire-bonder-assisted integration of non-bondable SMA wires into MEMS substrates

    NASA Astrophysics Data System (ADS)

    Fischer, A. C.; Gradin, H.; Schröder, S.; Braun, S.; Stemme, G.; van der Wijngaart, W.; Niklaus, F.

    2012-05-01

    This paper reports on a novel technique for the integration of NiTi shape memory alloy wires and other non-bondable wire materials into silicon-based microelectromechanical system structures using a standard wire-bonding tool. The efficient placement and alignment functions of the wire-bonding tool are used to mechanically attach the wire to deep-etched silicon anchoring and clamping structures. This approach enables a reliable and accurate integration of wire materials that cannot be wire bonded by traditional means.

  17. Combustibility of electrical wire and cable for rail rapid transit systems. Volume 2: Toxicity

    NASA Astrophysics Data System (ADS)

    Crane, C. B.; Sanders, D. C.; Endecott, B. R.; Abbott, J. K.

    1983-05-01

    The relative inhalation toxicity of the gases produced by thermal degradation of selected electrical insulation materials was determined. Six electrical wiring insulation materials were supplied by Factory Mutual Research and were evaluated for the toxic potential of their combustion products using the procedure developed at the Civil Aeromedical institute (CAML). Each of the materials was tested under flaming conditions at 750C with hot-wire ignition, and under nonflaming conditions at 550C. The work described in this report was performed between December 1981 and March 1982, and it consists of test criteria, animal response data, and a relative ranking of six insulation materials on the basis of the relative inhalation toxicity of their thermal degradation products.

  18. Crossed-feedback control of dual-redundancy permanent magnetic brushless dc servo system used in electro-hydrostatic actuator

    Microsoft Academic Search

    Zhou Qixun; Li Shengjin; Lu Gang; Zhou Yong

    2008-01-01

    Integrated electro-hydrostatic actuation system has the advantages of both small size and high power density. Dual-redundancy permanent magnet brushless DC motor (BLDCM) as the actuation component in electro-hydrostatic actuator (EHA) improves system reliability. But unequal electromagnetic torque in different redundant motor is a severe problem. It may impact the performance of the motor, even damage it. In this paper the

  19. An electrochemical study of corrosion protection by primer-topcoat systems on 4130 steel with ac impedance and dc methods

    NASA Technical Reports Server (NTRS)

    Mendrek, M. J.; Higgins, R. H.; Danford, M. D.

    1988-01-01

    To investigate metal surface corrosion and the breakdown of metal protective coatings, the ac impedance method is applied to six systems of primer coated and primer topcoated 4130 steel. Two primers were used: a zinc-rich epoxy primer and a red lead oxide epoxy primer. The epoxy-polyamine topcoat was used in four of the systems. The EG and G-PARC Model 368 ac impedance measurement system, along with dc measurements with the same system using the polarization resistance method, were used to monitor changing properties of coated 4230 steel disks immersed in 3.5 percent NaCl solutions buffered at pH 5.4 over periods of 40 to 60 days. The corrosion system can be represented by an electronic analog called an equivalent circuit consisting of resistors and capacitors in specific arrangements. This equivalent circuit parallels the impedance behavior of the corrosion system during a frequency scan. Values for the resistors and capacitors, that can be assigned in the equivalent circuit following a least-squares analysis of the data, describe changes that occur on the corroding metal surface and in the protective coatings. Two equivalent circuits have been determined that predict the correct Bode phase and magnitude of the experimental sample at different immersion times. The dc corrosion current density data are related to equivalent circuit element parameters. Methods for determining corrosion rate with ac impedance parameters are verified by the dc method.

  20. A Simplified Cascade Current Source Inverter Interconnected to Single-Phase Three-Wire Distribution System and Its Application to Electric Energy Storage System with Batteries

    Microsoft Academic Search

    Syuichi Iwata; Shigeo Masukawa; Shoji Iida

    2004-01-01

    A novel current source inverter system interconnected to the single-phase grid is proposed. It has the same construction as the conventional three-phase current source inverter that is interconnected to the single-phase three-wire distribution system. Though the proposed circuit has no output transformer, it can be equivalently performed as the single-phase double cascade inverter by diverting the pole transformer in the

  1. Minimization of wiring inductance in high power IGBT inverter

    Microsoft Academic Search

    Z. Lounis; I. Rasoanarivo; B. Davat

    2000-01-01

    The wiring inductance is one of main causes limiting the use of the inverter in hard commutation mode, particularly when voltage, current and switching frequency are increased. The busbar technology is the means that allows one to reach low wiring inductance between DC source and power switches in spite of relatively long connections. This paper deals with studies of busbar

  2. 47 CFR 68.213 - Installation of other than “fully protected” non-system simple customer premises wiring.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...b) Wiring authorized. Unprotected premises wiring may be used to connect units of terminal equipment or protective circuitry to one another, and to carrier-installed facilities if installed in accordance with these rules....

  3. 47 CFR 68.213 - Installation of other than “fully protected” non-system simple customer premises wiring.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...b) Wiring authorized. Unprotected premises wiring may be used to connect units of terminal equipment or protective circuitry to one another, and to carrier-installed facilities if installed in accordance with these rules....

  4. 47 CFR 68.213 - Installation of other than “fully protected” non-system simple customer premises wiring.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...b) Wiring authorized. Unprotected premises wiring may be used to connect units of terminal equipment or protective circuitry to one another, and to carrier-installed facilities if installed in accordance with these rules....

  5. Characteristics for Small Capacity Electric Energy Storage System with Batteries by Current Source Inverter

    Microsoft Academic Search

    Yasuhiro Ogura; Shigeo Masukawa; Shoji Iida

    2008-01-01

    We propose an electric energy storage system with batteries by a current source inverter. It is interconnected to the single-phase three-wire distribution system. In order to reduce the dc reactor capacity and change the discharging and the charging operations by signals, a set of DC-DC converters is added between the inverter and the batteries. In this paper, the proposed circuit

  6. Wires by Patchy Particles

    NSDL National Science Digital Library

    Zhang, Zhenli

    2005-01-31

    Simulation Software: Glotzer Group Code Simulation Method: Brownian Dynamics A system of 80 spherical particles with two patches at a concentration of 0.20, was run starting at an effectively infinite temperature then instantaneously quenched to a temperature of 0.5. The final equillibrium structure is wires or chains. Simulation Model: United Atom Rigid Body with Lennard-Jones

  7. The automated dc parameter testing of GaAs MESFETs using the Singer automatic integrated circuit test system

    NASA Astrophysics Data System (ADS)

    Harper, T. L.

    1980-09-01

    Procedures were developed to automate the manual testing of the DC parameters of GaAs MESFETs, integrated resistors and Schottky diodes. These devices are elements of a NAND/NOR logic circuit developed by Hewlett-Packard. The Singer Automatic Integrated Circuit Test System located at the Air Force Wright Aeronautical Laboratories, Avionics Laboratory (AFWAL/AADE), Wright-Patterson AFB, OH, was used to develop these procedures. The system was built by Singer Aerospace and Marine Systems, Glendale, California to test the dc parameters of semiconductor devices using Singer's Elucidate programming test language. The following DC parameters for the above devices were to be tested using the Singer tester: drain-to-source voltage (V sub DS), saturated drain current (I sub DSS) with gate-to-source voltage (V sub GS) at 0.0 volts, linear on-resistance and saturation resistance at V sub GS = 0.0 volts, pinch-off voltage (V sub P), transconductance (g sub M), breakdown voltage (BV)L at V sub GS = 0.0 volts, diode forward and reverse threshold voltages, and resistance. Test results have been obtained for the following MESFET parameters: V sub DS, I sub DSS, V sub GS, linear on-resistance and saturation resistance, V sub P and g sub M. Unfortunately, due to system measurement inaccuracies, these results do not compare favorably when compared with curve tracer I-V curves of the MESFETS.

  8. Beam profile wire-scanner/halo-scraper sensor analog interface electronics

    SciTech Connect

    Gruchalla, M. E.; O'Hara, J. F. (James F.); Barr, D. S. (Dean S.); Day, L. A. (Lisa A.); Gilpatrick, J. D. (John Douglas); Stettler, M. W. (Matthew W.); Martinez, D. G. (Derwin G.)

    2001-04-01

    The halo experiment presently being conducted at the Low Energy Demonstration Accelerator (LEDA) at Los Alamos National Laboratory utilizes a generally traditional wire scanner for measurement of the beam core profile and a graphite scraper for measurement of the tails of the beam distribution. A lossy integrator is used to detect the replacement charge flowing to the wire and scraper. Independent programmable dc-bias voltages are applied to the wire and the scraper through the analog electronic interface to optimize charge capture from the two sensors. A programmable guard voltage is applied to isolate the scraper from the resistivity of the cooling system. Programmable gain provides a total dynamic range in the analog electronics of greater than about one part in 10{sup 6}. The analog signal is digitized to 14 bits plus sign, and the equivalent input noise is nominally 30fC.

  9. NEMA wire and cable standards development programs

    NASA Technical Reports Server (NTRS)

    Baird, Robert W.

    1994-01-01

    The National Electrical Manufacturers Association (NEMA) is the nation's largest trade association for manufacturers of electrical equipment. Its member companies produce components, end-use equipment and systems for the generation, transmission, distribution, control and use of electricity. The wire and cable division is presented in 6 sections: building wire and cable, fabricated conductors, flexible cords, high performance wire and cable, magnet wire, and power and control cable. Participating companies are listed.

  10. The Geostationary Operational Satellite R Series SpaceWire Based Data System Architecture

    NASA Technical Reports Server (NTRS)

    Krimchansky, Alexander; Anderson, William H.; Bearer, Craig

    2010-01-01

    The GOES-R program selected SpaceWire as the best solution to satisfy the desire for simple and flexible instrument to spacecraft command and telemetry communications. Data generated by GOES-R instruments is critical for meteorological forecasting, public safety, space weather, and other key applications. In addition, GOES-R instrument data is provided to ground stations on a 24/7 basis. GOES-R requires data errors be detected and corrected from origin to final destination. This paper describes GOES-R developed strategy to satisfy this requirement

  11. Modeling, simulation, and control of an electromechanical aerofin control system with a PWM-controlled DC motor

    Microsoft Academic Search

    M. R. Ristanovic; D. V. Lazic; I. Indjin

    2008-01-01

    A nonlinear model of an electromechanical actuator (EMA) system for aerofin control is presented. The EMA is realized with\\u000a a permanent magnet brush DC motor controlled by a constant current driver. In this paper we introduced a simulation model\\u000a that includes nonlinearities of the motor driver. A PID position controller was designed using the simulation model, although\\u000a it was impossible

  12. Milliwatt dc/dc Inverter

    NASA Technical Reports Server (NTRS)

    Mclyman, C. W.

    1983-01-01

    Compact dc/dc inverter uses single integrated-circuit package containing six inverter gates that generate and amplify 100-kHz square-wave switching signal. Square-wave switching inverts 10-volt local power to isolated voltage at another desired level. Relatively high operating frequency reduces size of filter capacitors required, resulting in small package unit.

  13. Quantum wires as Luttinger liquids: theory

    NASA Astrophysics Data System (ADS)

    Sassetti, M.; Kramer, B.

    The present understanding of the physics of correlated electrons in quantum wires is summarized in terms of non-Fermi liquid collective excitations. The latter are determined within the Luttinger liquid model by using the bosonization technique. Charge and spin density modes are derived. Comparison with the data from resonant Raman scattering experiments indicates that interactions dominate the low-frequency collective excitations. The latter are determined within the Luttinger liquid model by using the bosonization technique. Charge and spin density modes are derived. Comparison with the data from resonant Raman scattering experiments indicates that interactions dominate the low-frequency collective modes in semiconductor quantum wires. Former "single particle excitations" in the resonant Raman spectra have been found to be due to higher-order spin modes that appear in both polarizations of incident and scattered light. The interplay in the non-linear DC-transport properties of a Luttinger liquid model with two impurities between interaction, spin, and backscattering by the impurities is discussed and compared with recent experiments. The results indicate that linear transport probes the global properties of the system, including the leads and the contacts. On the other hand, the non-linear differential conductance probes the local correlations near the electron island between the impurities.

  14. The low level radio frequency control system for DC-SRF photo-injector at Peking University

    E-print Network

    Wang, Fang; Lin, Lin; Hao, Jiankui; Quan, Shengwen; Zhang, Baocheng; Liu, Kexin

    2014-01-01

    A low level radio frequency (LLRF) control system is designed and constructed at Peking University, which is for the DC-SRF photo injector operating at 2K. Besides with continuous wave (CW), the system is also reliable with pulsed RF and pulsed beam, the stability of amplitude and phase can achieve 0.13% and 0.1{\\deg}respectively. It is worth noting that the system works perfectly when the cavity is driven at both generator driven resonator (GDR) and self-excited loop (SEL), the latter is useful in measuring the performance of the cavity.

  15. WireGL: A Scalable Graphics System for Clusters Greg Humphreys Matthew Eldridge Ian Buck Gordon Stoll Matthew Everett Pat Hanrahan

    E-print Network

    Stanford University

    : I.3.2 [Computer Graphics]: Graphics Systems-- Distributed/network graphics; I.3.4 [Computer GraphicsWireGL: A Scalable Graphics System for Clusters Greg Humphreys£ Matthew Eldridge£ Ian Buck£ GordonGL API to each node in a cluster, virtualizing multiple graphics accel- erators into a sort

  16. DC to DC power converters and methods of controlling the same

    DOEpatents

    Steigerwald, Robert Louis; Elasser, Ahmed; Sabate, Juan Antonio; Todorovic, Maja Harfman; Agamy, Mohammed

    2012-12-11

    A power generation system configured to provide direct current (DC) power to a DC link is described. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.

  17. Novel Radiopaque UHMWPE Sublaminar Wires in a Growth-Guidance System for the Treatment of Early Onset Scoliosis: Feasibility in a Large Animal Study.

    PubMed

    Bogie, R; Roth, Ak; Faber, S; de Jong, Jja; Welting, Tjm; Willems, Pc; Arts, Jj; van Rhijn, Lw

    2014-09-29

    Study Design. In vivo analysis in an ovine model.Objective. To evaluate the feasibility of radiopaque UHMWPE sublaminar wires in a growth-guidance spinal system by assessing stability, biocompatibility and growth potential.Summary of Background Data. Several growth-guidance systems have been developed for the treatment of early onset scoliosis (EOS). The use of gliding pedicle screws and metal sublaminar wires during these procedures can cause metal-on-metal debris formation and neurological deficits. Novel radiopaque UHMWPE wires are introduced to safely facilitate longitudinal growth and provide stability in a growth-guidance system for EOS.Methods. Twelve immature sheep received posterior segmental spinal instrumentation; pedicle screws were inserted at L5 and radiopaque UHWMPE (bismuth trioxide) wires were passed sublaminarly at each level between L3 and T11 and fixed to dual cobalt-chromiun rods. Four age-matched, unoperated animals were evaluated to serve as a control group. Radiographs were taken to measure growth of the instrumented segment. After 24 weeks, the animals were sacrificed and the spines were harvested for histological evaluation and high resolution peripheral quantitative computed tomography (HR-pQCT) analysis.Results. No neurological deficits occurred and all instrumentation remained stable. One animal died from an unknown cause. Substantial growth occurred in the instrumented segments (L5-T11) in the intervention group (27± 2 mm), which was not significantly different to the control group, (30 ± 4mm, p = 0.42). HR-pQCT analysis clearly showed safe routing and fixation of the UHMWPE wires and instrumentation. Despite the noted growth, ectopic bone formation with the formation of bony bridges was observed in all animals. Histology revealed no evidence of chronic inflammation or wear debris.Conclusions. This study shows the first results of radiopaque UHMWPE sublaminar wires as part of a growth guidance spinal system. UHMWPE sublaminar wires facilitated near-normal longitudinal spinal growth. All instrumentation remained stable throughout follow-up; no wire breakage or loosening occurred and no adverse local tissue response to these wires was observed. PMID:25271492

  18. DC Electronics

    NSDL National Science Digital Library

    This is a website with many learning objects on DC Electronics with over 60 lessons in areas including: Basic Concepts, Electrical Circuits / Meters, Ohm's Law, Magnetism, Parallel Circuits, Series/Parallel Circuits, Series/Parallel Applications and Series Circuits.

  19. Hierarchical Assembly of a Dual-responsive Macroscopic Insulated Molecular Wire Bundle in a Gradient System

    NASA Astrophysics Data System (ADS)

    Sheng, Yujie; Chen, Qibin; Yao, Junyao; Wang, Ying; Liu, Honglai

    2015-01-01

    Here, we report the hierarchical self-assembly of a cationic gemini amphiphile, Azo 1, in a composition gradient solution generated using solvent evaporation. As the gradient solution is formed, Azo 1 forms nanorods in the lower region of the solution. Depending on solvent composition, these nanorods can further develop into nanofibres, which can then intertwine to form double helices and other types of nanohelices in the upper region of the solution. Finally, a macroscopic wire bundle is formed via the fusion of nanohelices; this ribbon-like bundle exhibits elasticity and linear ohmic resistance properties. More intriguingly, this bundle exhibits photoresponsive properties that affect its deformation and conductivity, as well as a rapid electroresponse that affects its conductivity, indicating that it is feasible to control the charge pathway.

  20. Hierarchical assembly of a dual-responsive macroscopic insulated molecular wire bundle in a gradient system.

    PubMed

    Sheng, Yujie; Chen, Qibin; Yao, Junyao; Wang, Ying; Liu, Honglai

    2015-01-01

    Here, we report the hierarchical self-assembly of a cationic gemini amphiphile, Azo 1, in a composition gradient solution generated using solvent evaporation. As the gradient solution is formed, Azo 1 forms nanorods in the lower region of the solution. Depending on solvent composition, these nanorods can further develop into nanofibres, which can then intertwine to form double helices and other types of nanohelices in the upper region of the solution. Finally, a macroscopic wire bundle is formed via the fusion of nanohelices; this ribbon-like bundle exhibits elasticity and linear ohmic resistance properties. More intriguingly, this bundle exhibits photoresponsive properties that affect its deformation and conductivity, as well as a rapid electroresponse that affects its conductivity, indicating that it is feasible to control the charge pathway. PMID:25588881

  1. Hierarchical Assembly of a Dual-responsive Macroscopic Insulated Molecular Wire Bundle in a Gradient System

    PubMed Central

    Sheng, Yujie; Chen, Qibin; Yao, Junyao; Wang, Ying; Liu, Honglai

    2015-01-01

    Here, we report the hierarchical self-assembly of a cationic gemini amphiphile, Azo 1, in a composition gradient solution generated using solvent evaporation. As the gradient solution is formed, Azo 1 forms nanorods in the lower region of the solution. Depending on solvent composition, these nanorods can further develop into nanofibres, which can then intertwine to form double helices and other types of nanohelices in the upper region of the solution. Finally, a macroscopic wire bundle is formed via the fusion of nanohelices; this ribbon-like bundle exhibits elasticity and linear ohmic resistance properties. More intriguingly, this bundle exhibits photoresponsive properties that affect its deformation and conductivity, as well as a rapid electroresponse that affects its conductivity, indicating that it is feasible to control the charge pathway. PMID:25588881

  2. Generation of voltage fluctuations in power systems with DC arc furnaces

    Microsoft Academic Search

    D. Stade; H. Schau; M. Malsch; J. Hunermund; S. Prinz

    1998-01-01

    There is an increasing use of high-power DC arc furnaces for scrap melting all over the world. Onsite measurements in several steel plants with these furnaces have shown that flicker relevant voltage fluctuations cannot be prevented. The first reason is the time-varying need of reactive power. Also dynamic compensators like TCRs are often not able to avoid considerable flicker, particularly

  3. Tension Tests of Tungsten Based Sense Wires and Copper Based Field Wires for the COMPASS Drift Chamber 5

    NASA Astrophysics Data System (ADS)

    Wdaru, Abishek Reddy

    2014-09-01

    COMPASS is a nuclear physics experiment at CERN which explores the spin structure of the nucleon. A new drift chamber, DC5, is being constructed for the COMPASS spectrometer at the University of Illinois. DC5 will detect charged muon pairs from negative pions scattering off a transversely polarized proton target in order to study the spin-dependence of the Drell-Yan process for the first time. The spin dependence of the Drell-Yan process may signal contributions from quark orbital angular momentum to the spin of the proton. In DC5, particle detection is performed using 20 ?m diameter gold plated tungsten sense wires and 100 ?m diameter gold plated copper field wires. The wires are strung under tension across the length of the chamber. Mechanical stability under the influence of electric forces requires high wire tensions. In order to determine how much the wires can be stretched, a series of tension tests was performed to identify their regions of elasticity and their breaking points. The results from these tests were used to determine the tension used in stringing the wires and soldering them onto the printed circuit boards supporting the sense and field wires in DC5.

  4. Current dependence of heat leak on the terminals in the superconducting DC transmission and distribution system of CASER-2

    NASA Astrophysics Data System (ADS)

    Kawahara, Toshio; Watanabe, Hirofumi; Emoto, Masahiko; Hamabe, Makoto; Yamaguchi, Sataro; Hikichi, Yasuo; Minowa, Masahiro

    2012-12-01

    Superconductivity can solve the energy problems in the world as energy saving technologies. In particular, superconducting direct current (DC) transmission and distribution (T&D) systems is promising, as it can be easily extended to large scale energy transmission systems for energy sharing. We are developing criogenic systems for effective cooling of superconducting T&D systems. In the cooling experiments with the 200 m-class superconducting DC T&D system at Chubu University (CASER-2), we have estimated the performance of the system. For example, our superconducting cable is connected to the outside at the terminals using Peltier current leads (PCLs). The PCL is composed of a thermoelectric material and a copper lead. Small thermal conductivity and large thermopower of the thermoelectric modules can effectively insulate the heat leak to the low temperature end. We measured the temperature along the current leads and the heat leak at the terminals. As current leads have an optimal shape factor, the optimum operation current exists. The current dependence of the system performance is discussed.

  5. About the kinetic power induced by AC and DC discharges

    Microsoft Academic Search

    E. Moreau; G. Touchard

    2005-01-01

    This paper deals with experimental measurements of the ionic wind velocity of 3 types of corona discharges in air at atmospheric pressure: a DC surface discharge established between two wires flush mounted on the wall of a dielectric, a DC volume discharge in a point-to-grid geometry and an AC surface barrier discharge generated by application of a sine HV between

  6. A power flow diagnostic framework for multi-domain dynamic systems with application to drive-by-wire ground vehicles

    Microsoft Academic Search

    S. Ganta; J. Wagner

    2005-01-01

    The emergence of drive-by-wire (DBW) ground vehicles offers the opportunity for improved vehicle responsiveness, human-machine interface features, and environmental friendliness by permitting computercontrolled assistance. Multiple domain electro-mechanical components such as electronic throttle control (ETC), steer-by-wire (SBW), and brake-by-wire (BBW) replace the traditional mechanical and fluid linkages with sensors, actuators, and real-time computer control. From a safety perspective, these critical subsystems

  7. Fabrication of tungsten wire needles

    SciTech Connect

    Roder, A.

    1983-02-01

    Fine point needles for field emissoin are conventionally produced by electrolytically or chemically etching tungsten wire. Points formed in this manner have a typical tip radius of about 0.5 microns and a cone angle of some 30 degrees. The construction of needle matrix detector chambers has created a need for tungsten needles whose specifications are: 20 mil tungsten wire, 1.5 inch total length, 3 mm-long taper (resulting in a cone angle of about 5 degrees), and 25 micron-radius point (similar to that found on sewing needles). In the process described here for producing such needles, tungsten wire, immersed in a NaOH solution and in the presence of an electrode, is connected first to an ac voltage and then to a dc supply, to form a taper and a point on the end of the wire immersed in the solution. The process parameters described here are for needles that will meet the above specifications. Possible variations will be discussed under each approprite heading.

  8. 4He sample probe for combined microwave and dc transport measurements

    NASA Astrophysics Data System (ADS)

    Dobrovolskiy, Oleksandr V.; Franke, Jörg; Huth, Michael

    2015-03-01

    Combined microwave and dc electrical transport measurements at low temperatures represent a valuable experimental method in many research areas. In particular, when samples are conventional superconductors, a typical experiment requires a combination of helium temperatures, a wide range of magnetic fields, and the utilization of coaxial lines along with the usual dc wiring. We report on the general design features and the microwave performance of a custom-made low-temperature sample probe, with a measurement bandwidth tested from dc to 20 GHz. Equipped with six coaxial cables, a heater, Hall and temperature sensors, the probe fits into a ?32 mm shaft. We present our setup, analyze its microwave performance, and describe two representative experiments enabled by this system. The proposed setup will be essential for a systematic study of the dc and ac response of the vortex dynamics in nanopatterned superconductors subject to combined dc and microwave stimuli. Besides, it will be valuable for the investigation of a broad class of nonlinear stochastic systems where a combination of dc and high-frequency ac driving in a wide temperature range is necessary.

  9. Photovoltaic powered 20-hp DC/AC irrigation system and a 3-kW nitrogen generator

    SciTech Connect

    Hopkinson, R.F.

    1980-01-01

    A 25-kWp photovoltaic power system has been providing power for irrigation and crop drying since July 1977 at an agricultural field station of the University of Nebraska, located at Mead, Nebraska. The system was designed and built by Massachusetts Institute of Technology's Lincoln Laboratory under US Department of Energy sponsorship and is being operated jointly by the university and MIT Lincoln Laboratory. The system consists of a 25-kWp PV array, a battery subsystem, a power dump, an inverter, a controller and a data acquisition system. This photovoltaic power system has been used as a test facility in order to test and evaluate a variety of PV-related agricultural applications, including irrigation, crop drying and fertilizer manufacturing. Two interesting applications presently under evaluation are a 20-hp DC/AC-powered irrigation system and an on-site nitrogen fertilizer production unit.

  10. Composite superconducting wires obtained by high-rate tinning in molten Bi-Pb-Sr-Ca-Cu-O system

    NASA Technical Reports Server (NTRS)

    Grozav, A. D.; Konopko, L. A.; Leporda, N. I.

    1990-01-01

    The preparation of high-T(sub c) superconducting long composite wires by short-time tinning of the metal wires in a molten Bi-Pb-Sr-Ca-Cu-O compound is discussed. The application of this method to the high-T(sub c) materials is tested, possibly for the first time. The initial materials used for this experiment were ceramic samples with nominal composition Bi(1.5)Pb(0.5)Sr2Ca2Cu3O(x) and T(sub c) = 80 K prepared by the ordinary solid-state reaction, and industrial copper wires from 100 to 400 microns in diameter and from 0.5 to 1 m long. The continuously moving wires were let through a small molten zone (approximately 100 cubic mm). The Bi-based high-T(sub c) ceramics in a molten state is a viscous liquid and it has a strongly pronounced ability to spread on metal wire surfaces. The maximum draw rate of the Cu-wire, at which a dense covering is still possible, corresponds to the time of direct contact of wire surfaces and liquid ceramics for less than 0.1 s. A high-rate draw of the wire permits a decrease in the reaction of the oxide melt and Cu-wire. This method of manufacture led to the fabrication of wire with a copper core in a dense covering with uniform thickness of about h approximately equal to 5 to 50 microns. Composite wires with h approximately equal to 10 microns (h/d approximately equal to 0.1) sustained bending on a 15 mm radius frame without cracking during flexing.

  11. ac and dc conductivity, magnetoresistance, and scaling in cellular percolation systems

    Microsoft Academic Search

    C. Chiteme; D. S. McLachlan

    2003-01-01

    Percolation phenomena, which include the ac and dc conductivity, dielectric constant, and magnetoresistance, are studied in a series of seven cellular composites, consisting of small conductor particles embedded on the surface of larger insulator particles. Carbon black (ground and unground), graphite, graphite boron-nitride, niobium carbide, nickel, and magnetite (Fe3O4) powders were the conducting components with talc-wax powder as the common

  12. A comparison of soft-switched DC-to-DC converters for electrolyser application

    Microsoft Academic Search

    Deepak S. Gautam; A. K. S. Bhat

    2006-01-01

    An Electrolyser is part of a renewable energy system (RES) and generates hydrogen from water electrolysis that is used in fuel cells. A dc-to-dc converter is required to couple the Electrolyser to the system DC bus. This paper presents the design of three soft-switched high-frequency transformer isolated dc-to-dc converters for this application based on the given specifications. It is shown

  13. COBRA-STAR, a five frame point-projection x-ray imaging system for 1 MA scale wire-array Z pinches.

    PubMed

    Douglass, J D; Hammer, D A

    2008-03-01

    A new imaging system for 1 MA scale wire-array Z-pinch experiments that produces up to five high-resolution x-ray images per experimental pulse has been developed. Calibrated areal density measurements of the Z-pinch plasma can be obtained from each pulse. The system substitutes five molybdenum (Mo) X pinches for the normal copper return-current conductors to provide point sources of x-rays for point-projection radiography. Each backlighting X pinch consists of four Mo wires, the x-ray burst timing of which was controlled by varying the wire diameter (mass) from 10.2 to 30 microm in the five X pinches. Typical images have a 16x8 mm2 field of view at the wire array and a magnification of about 6.5:1 on the x-ray-sensitive film. Titanium (Ti) filters in front of the films transmit continuum radiation in the spectral range of 3-5 keV. Inclusion on the Ti of a step wedge having known thickness increments of the same material as the wires enables the calibrated areal density measurements to be made of the exploding wire plasmas. Here, we used tungsten (W) step wedges with step thicknesses ranging from 0.015 to 1.1 microm to obtain accurate (+/-10%) areal density measurements of W plasmas from the spatial profile of film exposure. When imaging arrays that produce intense radiation pulses, a plastic monofilament "quencher" is placed on axis to avoid film saturation. Images have subnanosecond temporal resolution and about 7 microm spatial resolution. PMID:18377006

  14. Quantitative Inspection of Broken Wire in Wire Ropes: Method and Apparatus.

    PubMed

    Hongjian; Kechong; Shuzi

    1996-01-01

    This paper introduces a complete system for automatic inspecting broken wire in wire ropes. The development of this technique is reviewed. It is followed by a description of the hardware and software of the apparatus. The hardware uses magnetic concentrators and Hall effect sensors. Signal analysis is based on wavelet processing. Quantitative identification of broken wire in wire ropes is based on a pattern recognition approach of the neural network. PMID:10602576

  15. Ionic wind generation by a wire-cylinder-plate corona discharge in air at atmospheric pressure

    SciTech Connect

    Colas, Dorian F.; Ferret, Antoine; Pai, David Z.; Lacoste, Deanna A.; Laux, Christophe O. [Laboratoire EM2C, UPR 288, CNRS, Ecole Centrale Paris, Grande Voie des Vignes, 92290 Chatenay-Malabry (France)

    2010-11-15

    A wire-cylinder-plate electrode configuration is presented to generate ionic wind with a dc corona discharge in air at atmospheric pressure. The objective of the work is to maximize the power supplied to the flow in order to increase acceleration while avoiding breakdown. Thus, the proposed experimental setup addresses the problem of decoupling the mechanism of ion generation from that of ion acceleration. Using a wire-plate configuration as a reference, we have focused on improving the topography of the electric field to (1) separate the ionization and acceleration zones in space, and (2) guide the trajectory of charged particles as parallel to the median axis as possible. In the proposed wire-cylinder-plate setup, a dc corona discharge is generated in the space between a wire and two cylinders. The ions produced by the corona then drift past the cylinders and into a channel between two plates, where they undergo acceleration. To maximize the ionic wind it is found that the geometric configuration must be as compact as possible and that the voltage applied must be right below breakdown. Experimentally, the optimized wire-plate reference setup provides a maximum flow velocity of 8 m s{sup -1}, a flow rate per unit electrode length of 0.034 m{sup 2} s{sup -1}, and a thrust per unit electrode length of 0.24 N m{sup -1}. The wire-cylinder-plate configuration provides a maximum flow velocity of 10 m s{sup -1}, a flow rate per unit electrode length of 0.041 m{sup 2} s{sup -1}, and a thrust per unit electrode length of 0.35 N m{sup -1}. This 46% increase in thrust is obtained by increasing the electric power per unit electrode length by only 16% (from 175 to 210 W m{sup -1}), which confirms the gain in efficiency obtained with the decoupled system. In comparison with a simple wire-wire corona configuration, the wire-cylinder-plate configuration increases the ionic wind velocity by up to a factor of 3, and the thrust by an order of magnitude.

  16. Ionic wind generation by a wire-cylinder-plate corona discharge in air at atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Colas, Dorian F.; Ferret, Antoine; Pai, David Z.; Lacoste, Deanna A.; Laux, Christophe O.

    2010-11-01

    A wire-cylinder-plate electrode configuration is presented to generate ionic wind with a dc corona discharge in air at atmospheric pressure. The objective of the work is to maximize the power supplied to the flow in order to increase acceleration while avoiding breakdown. Thus, the proposed experimental setup addresses the problem of decoupling the mechanism of ion generation from that of ion acceleration. Using a wire-plate configuration as a reference, we have focused on improving the topography of the electric field to (1) separate the ionization and acceleration zones in space, and (2) guide the trajectory of charged particles as parallel to the median axis as possible. In the proposed wire-cylinder-plate setup, a dc corona discharge is generated in the space between a wire and two cylinders. The ions produced by the corona then drift past the cylinders and into a channel between two plates, where they undergo acceleration. To maximize the ionic wind it is found that the geometric configuration must be as compact as possible and that the voltage applied must be right below breakdown. Experimentally, the optimized wire-plate reference setup provides a maximum flow velocity of 8 m s-1, a flow rate per unit electrode length of 0.034 m2 s-1, and a thrust per unit electrode length of 0.24 N m-1. The wire-cylinder-plate configuration provides a maximum flow velocity of 10 m s-1, a flow rate per unit electrode length of 0.041 m2 s-1, and a thrust per unit electrode length of 0.35 N m-1. This 46% increase in thrust is obtained by increasing the electric power per unit electrode length by only 16% (from 175 to 210 W m-1), which confirms the gain in efficiency obtained with the decoupled system. In comparison with a simple wire-wire corona configuration, the wire-cylinder-plate configuration increases the ionic wind velocity by up to a factor of 3, and the thrust by an order of magnitude.

  17. Modeling of a supersonic DC plasma torch system for carbon nanotube production

    NASA Astrophysics Data System (ADS)

    Guo, Liping

    The carbon nanotube (CNT) structure forms a very promising source material. It has unique properties such as high thermal and electrical conductivities, and a very high mechanical strength. In recent years, researchers were able to improve both the quantity and quality of the CNT production. Among the efforts made to scale up the production, Harbec and Meunier designed a new plasma torch process for the industrial production of CNT in bulk powder form. Their process is based on the DC plasma-jet pyrolysis of a carbon-containing gas. Experiments were conducted using either 100 slpm of argon or 225 slpm of helium. Tetrachloroethylene (C2Cl4, or TCE) was selected as the carbon raw material. The present work focuses on the modeling of this CNT synthesis process and aims at an understanding of the physical and chemical phenomena observed in this system. First, a description is made of the temperature and flow fields, as well as the species concentration distribution in the torch nozzle using both possibilities of He or Ar as the plasma gas. This is followed in the second part of the thesis by a model aimed to study the nucleation and evolution of the metal particles acting as catalyst for CNT growth in the nozzle. In the third part, the modeling of the TCE pyrolysis process in the flow was carried out. The fluid dynamics equations are used in this system showing supersonic characteristics. A realizable k-? model is used to address the turbulent effects in the flow fields. The moment method is employed to calculate the formation of the fine catalyst particles from the metal vapor injected. Within the supersonic domain of the flow field, the influence of existing shock waves on the particle nucleation is discussed, as well as the chemical reactions involved. Results show that the supersonic phenomena make it possible for metal particles to nucleate and be maintained in small sizes. This however also causes a backflow in the nozzle, which partially contributes to the experimentally observed soot deposition and CNT growth within the nozzle. The carbon containing gas experiences a fast dissociation process once it enters the nozzle. The produced carbon species are maintained in small clusters of carbon atoms in the high temperature environment within the nozzle. These clusters and atoms serve as the source of CNT growth and form a layer of carbon deposit on the surface of the nozzle. This deposited layer acts as a thermal insulator changing the conditions in the nozzle, particularly on the wall. A modeling of this effect is performed, confirming that the basic requirements for CNT growth are attained within the nozzle itself. A parametric study of the process is carried out and suggestions are made on the geometry of the reactor and the operating parameters for the formation of CNT. These modeling results suggest that the process can be optimized with carefully chosen operating parameters. With the specific design of the nozzle used here, it is recommended to operate at lower pressures in the reactor in order to avoid a backflow in the nozzle. Different kinds of metal catalyst can be used in this system and the reactor length should be adjusted accordingly in order to optimize the outcome of the process.

  18. Can an AC (alternating current) electrical system replace the present DC system in the automobile? An investigative feasibility study. II. Comparison and tradeoffs

    Microsoft Academic Search

    M. Abul Masrur; Daryl S. Sitar; V. A. Sankaran

    1998-01-01

    For Part I see ibid., vol.47, no.3, p.1072-80 (1998). In Part I of this paper, the possibility of using an AC (alternating current) electrical system instead of the present DC system in the automobile was discussed. The various possible architectures were described in Part I. Part II continues with the issues of various tradeoffs related to cost, size, and overall

  19. High intestinal and systemic levels of decoy receptor 3 (DcR3) and its ligand TL1A in active ulcerative colitis.

    PubMed

    Bamias, Giorgos; Kaltsa, Garyfallia; Siakavellas, Spyros I; Papaxoinis, Kostis; Zampeli, Evanthia; Michopoulos, Spyros; Zouboulis-Vafiadis, Irene; Ladas, Spiros D

    2010-11-01

    Decoy receptor-3 (DcR3) is a member of the TNF receptor superfamily of proteins, which has been implicated in anti-apoptotic and anti-inflammatory pathways, via binding to TL1A, LIGHT and Fas-L. The role of the TL1A/DcR3 ligand/receptor pair in ulcerative colitis (UC) has not been studied. We investigated the systemic (peripheral blood) and local (large intestine) expression of DcR3 and TL1A in 64 patients with UC and 56 healthy controls. DcR3 serum concentrations were highly elevated in patients with active UC (P<0.0001 vs. healthy controls). This elevation was clearly related to the presence of intestinal inflammation as it was less frequently observed in patients in remission (P=0.003 vs. active UC) whereas effective treatment resulted in disappearance or significant decrease of serum DcR3 (P=0.006 vs. pre-treatment). Furthermore, DcR3 mRNA transcripts were significantly elevated in inflamed areas of the colon (P=0.002 vs. non-affected of the same patient). In addition to DcR3 elevation, we found increased circulating levels of TL1A in patients with either active or inactive UC in comparison to healthy controls (P<0.001 for both). We conclude that elevated serum DcR3 may serve as an indicator of active colonic inflammation in patients with UC. TL1A/DcR3-mediated pathways may participate in the pathogenesis of UC. PMID:20675196

  20. The UT 19-channel DC SQUID based neuromagnetometer.

    PubMed

    ter Brake, H J; Flokstra, J; Jaszczuk, W; Stammis, R; van Ancum, G K; Martinez, A; Rogalla, H

    1991-01-01

    A 19-channel DC SQUID based neuromagnetometer is under construction at the University of Twente (UT). Except for the cryostat all elements of the system are developed at the UT. It comprises 19 wire-wound first-order gradiometers in a hexagonal configuration. The gradiometers are connected to planar DC SQUIDs fabricated with a Nb/Al, AlO kappa/Nb technology. For this connection we developed a method to bond a Nb wire to a Nb thin-film. The SQUIDs are placed in compartmentalised Nb modules. Further, external feedback is incorporated in order to eliminate cross talk between the gradiometers. The electronics basically consist of a phase-locked loop operating with a modulation frequency of 100 kHz. Between SQUID and preamplifier a small transformer is used to limit the noise contribution of the preamplifier. In the paper the overall system is described, and special attention is paid to the SQUID module (bonding, compartments, external-feedback setup, output transformer). PMID:1807878

  1. Auxiliary resonant DC tank converter

    DOEpatents

    Peng, Fang Z. (Knoxville, TN)

    2000-01-01

    An auxiliary resonant dc tank (ARDCT) converter is provided for achieving soft-switching in a power converter. An ARDCT circuit is coupled directly across a dc bus to the inverter to generate a resonant dc bus voltage, including upper and lower resonant capacitors connected in series as a resonant leg, first and second dc tank capacitors connected in series as a tank leg, and an auxiliary resonant circuit comprising a series combination of a resonant inductor and a pair of auxiliary switching devices. The ARDCT circuit further includes first clamping means for holding the resonant dc bus voltage to the dc tank voltage of the tank leg, and second clamping means for clamping the resonant dc bus voltage to zero during a resonant period. The ARDCT circuit resonantly brings the dc bus voltage to zero in order to provide a zero-voltage switching opportunity for the inverter, then quickly rebounds the dc bus voltage back to the dc tank voltage after the inverter changes state. The auxiliary switching devices are turned on and off under zero-current conditions. The ARDCT circuit only absorbs ripples of the inverter dc bus current, thus having less current stress. In addition, since the ARDCT circuit is coupled in parallel with the dc power supply and the inverter for merely assisting soft-switching of the inverter without participating in real dc power transmission and power conversion, malfunction and failure of the tank circuit will not affect the functional operation of the inverter; thus a highly reliable converter system is expected.

  2. Plasma Sputter-type Ion Source with Wire Electrodes for Low-energy Gallium Ion Extraction

    SciTech Connect

    Vasquez, M. Jr.; Kasuya, T.; Wada, M. [Graduate School of Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321 (Japan); Maeno, S. [Novelion Systems Co. Ltd., Kyotanabe, Kyoto 610-0332 (Japan); Miyamoto, N. [Nissin Ion Equipment Co. Ltd., Minami-ku, Kyoto 601-8205 (Japan)

    2011-01-07

    Low-energy ions of gallium (Ga) and argon (Ar) were extracted from a plasma sputter-type ion source system that utilized a tungsten (W) wire extractor geometry. The 90% transparent W wire extractor configuration had shown that the system was capable of producing an ion beam with the energy as low as 10 eV in a dc filament discharge and 50 eV in a radio frequency (rf) excited system. In the present investigation, Ar plasma was sustained in an ion source chamber through an inductively coupled 13.56 MHz rf power source. Negatively biased liquid Ga target suspended on a W reservoir was sputtered and postionized prior to extraction. Mass spectral analyses revealed a strong dependence of the Ga{sup +} current on the induced target bias.

  3. The structure and properties of pulsed dc magnetron sputtered nanocrystalline TiN films for electrodes of alkali metal thermal-to-electric conversion systems.

    PubMed

    Chun, Sung-Yong

    2013-03-01

    Titanium nitride films used as an important electrode material for the design of alkali metal thermal-to-electric conversion (AMTEC) system have been prepared using dc (direct current) and asymmetric-bipolar pulsed dc magnetron sputtering. The pulse frequency and the duty cycle were varied from 5 to 50 kHz and 50 to 95%, respectively. The deposition rate, grain size and resistivity of pulsed dc sputtered films were decreased when the pulse frequency increased, while the nano hardness of titanium nitride films increased. We present in detail coatings (e.g., deposition rate, grain size, prefer-orientation, resistivity and hardness). Our studies show that titanium nitride coatings with superior properties can be prepared using asymmetric-bipolar pulsed dc sputtering. PMID:23755636

  4. High power DC-to-DC converter for supercapacitors

    Microsoft Academic Search

    B. J. Arnet; L. P. Haines

    2001-01-01

    The purpose of this paper is to present Solectria's approach to the design and realization of a high power, nonisolated DC-to-DC power converter for supercapacitors. The study focuses on supercapacitor specific design rules and on how to integrate the unit into a system with other energy storage devices and converters. Two applications are presented to illustrate the validity of the

  5. LLC resonant converter for front end DC\\/DC conversion

    Microsoft Academic Search

    Bo Yang; Fred C. Lee; Alpha J. Zhang; Guisong Huang

    2002-01-01

    A new LLC resonant converter is proposed for front end DC\\/DC conversion in a distributed power system. Three advantages are achieved with this resonant converter. First, ZVS turn on and low turn off current of MOSFETs are achieved. The switching loss is reduced so we can operate the converter at higher switching frequency. The second advantage is that with this

  6. Adjustable Bracket For Entry Of Welding Wire

    NASA Technical Reports Server (NTRS)

    Gilbert, Jeffrey L.; Gutow, David A.

    1993-01-01

    Wire-entry bracket on welding torch in robotic welding system provides for adjustment of angle of entry of welding wire over range of plus or minus 30 degrees from nominal entry angle. Wire positioned so it does not hide weld joint in view of through-the-torch computer-vision system part of robot-controlling and -monitoring system. Swiveling bracket also used on nonvision torch on which wire-feed-through tube interferes with workpiece. Angle simply changed to one giving sufficient clearance.

  7. Technology update I: Wiring prognostic tools

    Microsoft Academic Search

    C. Teal; W. Larsen

    2003-01-01

    Current wire system inspection processes do not compliment aircraft electrical and electronic systems technology nor do many proposed or existing systems. The volt\\/ohm meter, the meg\\/ohm meter, and visual techniques can represent the wire inspection tools in common use today. These two meters only measure conductivity, connectivity, and voltage breakdown strength of the insulation. Visual techniques (mirror and flashlight methods)

  8. Power sensor-less MPPT control scheme utilizing power balance at DC link-system design to ensure stability and response

    Microsoft Academic Search

    Tatsuya Kitano; Mikihiko Matsui; De-hong Xu

    2001-01-01

    The authors previously proposed a new MPPT (maximum power point tracking) control scheme for PV (photovoltaic) power systems connected in parallel with the AC system line. It is characterised by utilizing power balance at the DC link under steady state conditions, hence eliminating the array output power detection and achieving power sensorless operation. However, the system response and stability greatly

  9. Vibration Monitoring of the Voigt Bridge using Wired and Wireless Monitoring Systems

    Microsoft Academic Search

    Yang Wang; Kenneth J. Loh; Jerome P. Lynch; Michael Fraser; Kincho Law; Ahmed Elgamal

    2006-01-01

    Structural monitoring systems using wireless sensors have the potential to serve as low-cost alternatives to commercially available cable-based monitoring systems. This paper describes a wireless sensing prototype system specifically designed for structural monitoring applications. To validate the performance of the prototype system, a network of up to 20 wireless sensing units is installed on the Voigt Bridge located on the

  10. HTS Wire Development Workshop: Proceedings

    SciTech Connect

    Not Available

    1994-07-01

    The 1994 High-Temperature Superconducting Wire Development Workshop was held on February 16--17 at the St. Petersburg Hilton and Towers in St. Petersburg, Florida. The meeting was hosted by Florida Power Corporation and sponsored by the US Department of Energy`s Superconductivity Program for Electric Power Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. The meeting opened with a general discussion on the needs and benefits of superconductivity from a utility perspective, the US global competitiveness position, and an outlook on the overall prospects of wire development. The meeting then focused on four important technology areas: Wire characterization: issues and needs; technology for overcoming barriers: weak links and flux pinning; manufacturing issues for long wire lengths; and physical properties of HTS coils. Following in-depth presentations, working groups were formed in each technology area to discuss the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  11. Simple dc-SQUID system based on a frequency modulated relaxation oscillator

    SciTech Connect

    Muck, M.; Heiden, C.

    1989-03-01

    Nanobridges with hysteretic I-V-characteristics can be operated as relaxation oscillators when connected to an R-L shunt. A dc-SQUID configuration results, if two such oscillators are incorporated in a superconducting ring. Operating such a self-oscillating SQUID or SOS With a suitable bias current leads to an output signal of the order of 10 mV, whose frequency depends on the magnetic flux through the SQUID-ring modulo PHI/sub o/. Due to this large output voltage, no impedance matching nor a special low noise preamplifier are needed for the read-out scheme. Standard integrated circuits for fm signal processing can be used leading to matchbox-size electronics. Such dc-SQUIDS have been made of thin Nb, NbN, and Nb/sub 3/Ge films, the highest sensitivity resulting so far for Nb devices with a white flux noise below 10%-5% PHI/sub o//..sqrt.. Hz at 4.2 K.

  12. Development of real-time monitoring system using wired and wireless networks in a full-scale ship

    NASA Astrophysics Data System (ADS)

    Paik, Bu-Geun; Cho, Seong-Rak; Park, Beom-Jin; Lee, Dongkon; Bae, Byung-Dueg

    2010-09-01

    In the present study, the real-time monitoring system is developed based on the wireless sensor network (WSN) and power line communication (PLC) employed in the 3,000-ton-class training ship. The WSN consists of sensor nodes, router, gateway and middleware. The PLC is composed of power lines, modems, Ethernet gateway and phase-coupler. The basic tests show that the ship has rather good environments for the wired and wireless communications. The developed real-time monitoring system is applied to recognize the thermal environments of main-engine room and one cabin in the ship. The main-engine room has lots of heat sources and needs careful monitoring to satisfy safe operation condition or detect any human errors beforehand. The monitoring is performed in two regions near the turbocharger and cascade tank, considered as heat sources. The cabin on the second deck is selected to monitor the thermal environments because it is close to the heat source of main engine. The monitoring results of the cabin show the thermal environment is varied by the human activity. The real-time monitoring for the thermal environment would be useful for the planning of the ventilation strategy based on the traces of the human activity against inconvenient thermal environments as well as the recognizing the temperature itself in each cabin.

  13. High-angle tilt boundary graphene domain recrystallized from mobile hot-wire-assisted chemical vapor deposition system.

    PubMed

    Lee, Jinsup; Baek, Jinwook; Ryu, Gyeong Hee; Lee, Mi Jin; Oh, Seran; Hong, Seul Ki; Kim, Bo-Hyun; Lee, Seok-Hee; Cho, Byung Jin; Lee, Zonghoon; Jeon, Seokwoo

    2014-08-13

    Crystallization of materials has attracted research interest for a long time, and its mechanisms in three-dimensional materials have been well studied. However, crystallization of two-dimensional (2D) materials is yet to be challenged. Clarifying the dynamics underlying growth of 2D materials will provide the insight for the potential route to synthesize large and highly crystallized 2D domains with low defects. Here, we present the growth dynamics and recrystallization of 2D material graphene under a mobile hot-wire assisted chemical vapor deposition (MHW-CVD) system. Under local but sequential heating by MHW-CVD system, the initial nucleation of nanocrystalline graphenes, which was not extended into the growth stage due to the insufficient thermal energy, took a recrystallization and converted into a grand single crystal domain. During this process, the stitching-like healing of graphene was also observed. The local but sequential endowing thermal energy to nanocrystalline graphenes enabled us to simultaneously reveal the recrystallization and healing dynamics in graphene growth, which suggests an alternative route to synthesize a highly crystalline and large domain size graphene. Also, this recrystallization and healing of 2D nanocrystalline graphenes offers an interesting insight on the growth mechanism of 2D materials. PMID:24978293

  14. Power Network impedance effects on noise emission of DC-DC converters

    NASA Astrophysics Data System (ADS)

    Esteban, M. C.; Arteche, F.; Iglesias, M.; Gimeno, A.; Arcega, F. J.; Johnson, M.; Cooper, W. E.

    2012-01-01

    The characterization of electromagnetic noise emissions of DC-DC converters is a critical issue that has been analyzed during the desing phase of CMS tracker upgrade. Previous simulation studies showed important variations in the level of conducted emissions when DC-DC converters are loaded/driven by different impedances and power network topologies. Several tests have been performed on real DC-DC converters to validate the Pspice model and simulation results. This paper presents these test results. Conducted noise emissions at the input and at the output terminals of DC-DC converters has been measured for different types of power and FEE impedances. Special attention has been paid to influence on the common-mode emissions by the carbon fiber material used to build the mechanical structure of the central detector. These study results show important recommendations and criteria to be applied in order to decrease the system noise level when integrating the DC-DC.

  15. Design of a wide input range DC\\/DC converter based on SEPIC topology for fuel cell power conversion

    Microsoft Academic Search

    A. Chih-Chiang Hua; B. Cheng-you Tsai

    2010-01-01

    This thesis presents the design and implementation of a wide input range DC\\/DC converter based on SEPIC topology for fuel cell power system. The power converters can not only transfer the power from fuel cells to the load, but also improve stability and safety of the system. In the proposed system, a SEPIC DC\\/DC converter is designed to boost the

  16. Quasi Linear DC\\/DC Converters

    Microsoft Academic Search

    Deepak M. Divan; Satish Rajagopalan

    2006-01-01

    Demanding high power applications, such as medical imaging, fast processors, and pulsed loads are requiring new levels of performance from dc\\/dc converters. Extremely low ripple voltages, blazing speed and response, all with high efficiency and small size are placing conflicting requirements on the dc\\/dc converter designer. Conventional design approaches are not able to meet the needs easily, and it is

  17. NONLINEAR PID CONTROLLER MODIFICATION OF THE ELECTROMECHANICAL ACTUATOR SYSTEM FOR AEROFIN CONTROL WITH A PWM CONTROLLED DC MOTOR UDC 681.515.8

    Microsoft Academic Search

    FACTA UNIVERSITATIS

    2008-01-01

    In this paper, we investigate the control of an electromechanical actuator (EMA) system for aerofin control (AFC). The EMA is realized with permanent magnet brush DC motor controlled by constant current driver. Using nonlinear model of the EMA-AFC system that includes nonlinearities of the motor driver, a PID position controller is designed. In this paper we proposed the control algorithm

  18. Analysis and development of a low-cost permanent magnet brushless DC motor drive for PV-array fed water pumping system

    Microsoft Academic Search

    Bhim Singh; C. L. Putta Swamy

    1998-01-01

    This paper deals with the analysis and development of a permanent magnet brushless DC (PMBLDC) motor drive coupled to a pump load powered by solar photovoltaic (PV) array for water pumping system. A simple low-cost prototype controller has been designed and developed without current and position sensors which reduces drastically the overall cost of the drive system. This controller is

  19. Cipher Printing Telegraph Systems For Secret Wire and Radio Telegraphic Communications

    Microsoft Academic Search

    G. S. Vernam

    1926-01-01

    This paper describes a printing telegraph cipher system devetoped during the World War for the use of the Signal Corps, U. S. Army. This system is so designed that the messages are in secret form from the time they leave the sender until they are deciphered automatically at the office of the addressee. If copied while en route, the messages

  20. 49 CFR 236.108 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Insulation resistance tests, wires in trunking...Tests; All Systems § 236.108 Insulation resistance tests, wires in trunking and cables. (a) Insulation resistance of wires and...

  1. 49 CFR 236.108 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Insulation resistance tests, wires in trunking...Tests; All Systems § 236.108 Insulation resistance tests, wires in trunking and cables. (a) Insulation resistance of wires and...

  2. 49 CFR 236.108 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Insulation resistance tests, wires in trunking...Tests; All Systems § 236.108 Insulation resistance tests, wires in trunking and cables. (a) Insulation resistance of wires and...

  3. 49 CFR 236.108 - Insulation resistance tests, wires in trunking and cables.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Insulation resistance tests, wires in trunking...Tests; All Systems § 236.108 Insulation resistance tests, wires in trunking and cables. (a) Insulation resistance of wires and...

  4. Radiation interlocks: The choice between conventional hard-wired logic and computer-based systems

    SciTech Connect

    Crook, K.F.

    1986-11-01

    During the past few years, the use of computers in radiation safety systems has become more widespread. This is not surprising given the ubiquitous nature of computers in the modern technological world. But is a computer a good choice for the central logic element of a personnel safety system. Recent accidents at computer controlled medical accelerators would indicate that extreme care must be exercised if malfunctions are to be avoided. The Department of Energy has recently established a sub-committee to formulate recommendations on the use of computers in safety systems for accelerators. This paper will review the status of the committee's recommendations, and describe radiation protection interlock systems as applied to both accelerators and to irradiation facilities. Comparisons are made between the conventional relay approach and designs using computers. 6 refs., 6 figs.

  5. A Fault Tolerant Time Triggered Protocol for Drive-by-Wire Systems

    Microsoft Academic Search

    Aakash Arora; Praveen R. Ramteke; Syed Masud Mahmud

    Automakers are scrambling to implement advanced safety and engine management systems to make vehicles safer and more fuel-efficient, as well as meet growing consumer and government demands. Continuous demands for fuel efficiency mandate \\

  6. The Virtual Wires Emulation System: A Gate-Efficient ASIC Prototyping Environment

    Microsoft Academic Search

    Russell Tessier; Jonathan Babb; Matthew Dahl; Silvina Hanono; David Hoki

    1994-01-01

    FPGA-based ASIC development systems have become importanttools in contemporary ASIC design. Existing systemsexhibit low per-FPGA gate utilization (10 to 20 percent)due to limited inter-chip communication. Attempts at overcomingthis limitation through the use of high dimensionalinterconnection topologies have met with limited success.This paper focuses on the prototype hardware and softwareinterfaces that have been developed for an FPGA-basedASIC emulation system based on

  7. Wire Test Grip Fixture

    NASA Technical Reports Server (NTRS)

    Burke, Christopher S.

    2011-01-01

    Wire-testing issues, such as the gripping strains imposed on the wire, play a critical role in obtaining clean data. In a standard test frame fitted with flat wedge grips, the gripping action alone creates stresses on the wire specimen that cause the wire to fail at the grip location. A new test frame, which is outfitted with a vacuum chamber, negated the use of any conventional commercially available wire test fixtures, as only 7 in. (17.8 cm) existed between the grip faces. An innovative grip fixture was designed to test thin gauge wire for a variety of applications in an existing Instron test frame outfitted with a vacuum chamber.

  8. RISK D/C

    NASA Technical Reports Server (NTRS)

    Dias, W. C.

    1994-01-01

    RISK D/C is a prototype program which attempts to do program risk modeling for the Space Exploration Initiative (SEI) architectures proposed in the Synthesis Group Report. Risk assessment is made with respect to risk events, their probabilities, and the severities of potential results. The program allows risk mitigation strategies to be proposed for an exploration program architecture and to be ranked with respect to their effectiveness. RISK D/C allows for the fact that risk assessment in early planning phases is subjective. Although specific to the SEI in its present form, RISK D/C can be used as a framework for developing a risk assessment program for other specific uses. RISK D/C is organized into files, or stacks, of information, including the architecture, the hazard, and the risk event stacks. Although predefined, all stacks can be upgraded by a user. The architecture stack contains information concerning the general program alternatives, which are subsequently broken down into waypoints, missions, and mission phases. The hazard stack includes any background condition which could result in a risk event. A risk event is anything unfavorable that could happen during the course of a specific point within an architecture, and the risk event stack provides the probabilities, consequences, severities, and any mitigation strategies which could be used to reduce the risk of the event, and how much the risk is reduced. RISK D/C was developed for Macintosh series computers. It requires HyperCard 2.0 or later, as well as 2Mb of RAM and System 6.0.8 or later. A Macintosh II series computer is recommended due to speed concerns. The standard distribution medium for this package is one 3.5 inch 800K Macintosh format diskette. RISK D/C was developed in 1991 and is a copyrighted work with all copyright vested in NASA. Macintosh and HyperCard are trademarks of Apple Computer, Inc.

  9. Analysis of thin-wire ground penetrating radar systems for buried target detection, using a hybrid MoM-FDTD technique

    Microsoft Academic Search

    N. Farnoosh; A. Shoory; R. Moini; S. H. H. Sadeghi

    2008-01-01

    A hybrid method combining the finite difference time domain (FDTD) method and the method of moments (MoM) in the frequency domain is proposed to model the electromagnetic behavior of a realistic ground penetrating radar (GPR) system. The GPR is a non-destructive testing (NDT) technique. It consists of a broadband thin-wire vee-dipole antenna located in the vicinity of a lossy ground

  10. Transport Through Carbon Nanotube Wires

    NASA Technical Reports Server (NTRS)

    Anantram, M. P.; Kwak, Dochan (Technical Monitor)

    2001-01-01

    This viewgraph presentation deals with the use of carbon nanotubes as a transport system. Contact, defects, tubular bend, phonons, and mechanical deformations all contribute to reflection within the nanotube wire. Bragg reflection, however, is native to an ideal energy transport system. Transmission resistance depends primarily on the level of energy present. Finally, the details regarding coupling between carbon nanotubes and simple metals are presented.

  11. Modular Wiring Offers Cost Savings and Future Flexibility.

    ERIC Educational Resources Information Center

    Ewald, Mike; Ewald, Ann O'Connor

    2002-01-01

    Discusses the advantages of modular wiring, a prefabricated wiring system that replaces branch circuits in buildings. Advantages include on-site and day-to-day labor savings, and future technology cost advantages. Includes questions to ask manufacturers. (EV)

  12. 24 CFR 3280.814 - Painting of wiring.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...5 2012-04-01 2012-04-01 false Painting of wiring. 3280.814 Section 3280.814...STANDARDS Electrical Systems § 3280.814 Painting of wiring. During painting or staining of the manufactured home, it...

  13. 24 CFR 3280.814 - Painting of wiring.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...5 2013-04-01 2013-04-01 false Painting of wiring. 3280.814 Section 3280.814...STANDARDS Electrical Systems § 3280.814 Painting of wiring. During painting or staining of the manufactured home, it...

  14. 24 CFR 3280.814 - Painting of wiring.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...5 2011-04-01 2011-04-01 false Painting of wiring. 3280.814 Section 3280.814...STANDARDS Electrical Systems § 3280.814 Painting of wiring. During painting or staining of the manufactured home, it...

  15. 24 CFR 3280.814 - Painting of wiring.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...5 2014-04-01 2014-04-01 false Painting of wiring. 3280.814 Section 3280.814...STANDARDS Electrical Systems § 3280.814 Painting of wiring. During painting or staining of the manufactured home, it...

  16. DC voltage sensorless control strategy of grid-tied two-stage three-phase photovoltaic system

    Microsoft Academic Search

    Jianhua Yuan; Feng Gao; Houlei Gao

    2011-01-01

    The variable dc voltage generated by photovoltaic (PV) array can be harnessed as much as possible through the well-known two-stage inversion in grid- tied configuration, where the controlled dc-link voltage can be maintained stably to ensure the desired low harmonic ac output. Traditionally, the front-end dc Boost converter generally operates to track the maximum power point (MPP) of PV array

  17. Two-stage actuation system using DC motors and piezoelectric actuators for controllable industrial and automotive brakes and clutches

    NASA Astrophysics Data System (ADS)

    Neelakantan, Vijay A.; Washington, Gregory N.; Bucknor, Norman K.

    2005-05-01

    High bandwidth actuation systems that are capable of simultaneously producing relatively large forces and displacements are required for use in automobiles and other industrial applications. Conventional hydraulic actuation mechanisms used in automotive brakes and clutches are complex, inefficient and have poor control robustness. These lead to reduced fuel economy, controllability issues and other disadvantages. This paper involves the design, development, testing and control of a two-stage hybrid actuation mechanism by combining classical actuators like DC motors and advanced smart material actuators like piezoelectric actuators. The paper also discusses the development of a robust control methodology using the Internal Model Control (IMC) principle and emphasizes the robustness property of this control methodology by comparing and studying simulation and experimental results.

  18. A Wire Position Monitor System for the 1.3 FHZ Tesla-Style Cryomodule at the Fermilab New-Muon-Lab Accelerator

    SciTech Connect

    Eddy, N.; Fellenz, B.; Prieto, P.; Semenov, A.; Voy, D.C.; Wendt, M.; /Fermilab

    2011-08-17

    The first cryomodule for the beam test facility at the Fermilab New-Muon-Lab building is currently under RF commissioning. Among other diagnostics systems, the transverse position of the helium gas return pipe with the connected 1.3 GHz SRF accelerating cavities is measured along the {approx}15 m long module using a stretched-wire position monitoring system. An overview of the wire position monitor system technology is given, along with preliminary results taken at the initial module cooldown, and during further testing. As the measurement system offers a high resolution, we also discuss options for use as a vibration detector. An electron beam test facility, based on superconducting RF (SRF) TESLA-style cryomodules is currently under construction at the Fermilab New-Muon-Lab (NML) building. The first, so-called type III+, cryomodule (CM-1), equipped with eight 1.3 GHz nine-cell accelerating cavities was recently cooled down to 2 K, and is currently under RF conditioning. The transverse alignment of the cavity string within the cryomodule is crucial for minimizing transverse kick and beam break-up effects, generated by the high-order dipole modes of misaligned accelerating structures. An optimum alignment can only be guaranteed during the assembly of the cavity string, i.e. at room temperatures. The final position of the cavities after cooldown is uncontrollable, and therefore unknown. A wire position monitoring system (WPM) can help to understand the transverse motion of the cavities during cooldown, their final location and the long term position stability after cryo-temperatures are settled, as well as the position reproducibility for several cold-warm cycles. It also may serve as vibration sensor, as the wire acts as a high-Q resonant detector for mechanical vibrations in the low-audio frequency range. The WPM system consists out of a stretched-wire position detection system, provided with help of INFN-Milano and DESY Hamburg, and RF generation and read-out electronics, developed at Fermilab.

  19. Computer-aided optimization of DC/DC converters for automotive applications

    E-print Network

    Neugebauer, Timothy C.

    This paper investigates computer-aided optimization of DC/DC converters, with a focus on converters for dual-voltage automotive electrical systems. A new CAD optimization approach based on Monte Carlo search methods is ...

  20. The Virtual Wires Emulation System: A Gate-Efficient ASIC Prototyping Environment

    Microsoft Academic Search

    Russell Tessier; Jonathan Babb; Matthew Dahl; Silvina Hanono; Anant Agarwal

    FPGA-based ASIC development systems have become im- portant tools in contemporary ASIC design. Existing sys- tems exhibit low per-FPGA gate utilization (10 to 20 percent) due to limited inter-chip communication. Attempts at over- coming this limitation through the use of high dimensional interconnection topologies have met with limited success. This paper focuses on the prototype hardware and soft- ware interfaces

  1. Introduction of DC line structures into a superconducting microwave 3D cavity

    NASA Astrophysics Data System (ADS)

    Kong, Wei-Cheng; Deng, Guang-Wei; Li, Shu-Xiao; Li, Hai-Ou; Cao, Gang; Xiao, Ming; Guo, Guo-Ping

    2015-02-01

    We report a technique that can noninvasively add multiple DC wires into a 3D superconducting microwave cavity for electronic devices that require DC electrical terminals. We studied the influence of our DC lines on the cavity performance systematically. We found that the quality factor of the cavity is reduced if any of the components of the electrical wires cross the cavity equipotential planes. Using this technique, we were able to incorporate a quantum dot (QD) device into a 3D cavity. We then controlled and measured the QD transport signal using the DC lines. We have also studied the heating effects of the QD by the microwave photons in the cavity.

  2. Wire harness twisting aid

    NASA Technical Reports Server (NTRS)

    Casey, E. J.; Commadore, C. C.; Ingles, M. E.

    1980-01-01

    Long wire bundles twist into uniform spiral harnesses with help of simple apparatus. Wires pass through spacers and through hand-held tool with hole for each wire. Ends are attached to low speed bench motor. As motor turns, operator moves hand tool away forming smooth twists in wires between motor and tool. Technique produces harnesses that generate less radio-frequency interference than do irregularly twisted cables.

  3. The future of wires

    Microsoft Academic Search

    R. Ho; K. W. Mai; M. A. Horowitz

    1991-01-01

    Concern about the performance of wires in scaled technologies has led to research exploring other communication methods. This paper examines wire and gate delays as technologies migrate from 0.18-m to 0.035-m feature sizes to better understand the magni-tude of the wiring problem. Wires that shorten in length as technolo-gies scale have delays that either track gate delays or grow slowly

  4. A DSP Based Controller for High Power Dual-Phase DC-DC Converters

    Microsoft Academic Search

    Xin Guo; Xuhui Wen; Ermin Qiao

    2006-01-01

    High power DC\\/DC converter has become the essential part of the distributed power system in fuel cell powered electric vehicles and stationary power systems. This paper proposes a topology of high power dual-phase boost DC\\/DC converter for fuel cell power supply. The principle of the converter operating in BOOST mode are analyzed thoroughly. A 150 KW converter was designed. The

  5. Motion control of the accumulator flying wires

    Microsoft Academic Search

    1990-01-01

    Flying wire systems for the Fermilab Accumulator are being constructed in order to measure the transverse beam profiles during stacking. Each device passes a 25 micron carbon filament through the beam transversely at a constant velocity of 10 m\\/s. Collisions between the beam particles and the wire produce secondary particle cascades, which in turn produce photons in a scintillator. A

  6. Laser Wire Stripper

    NASA Technical Reports Server (NTRS)

    1983-01-01

    NASA-developed space shuttle technology is used in a laser wire stripper designed by Raytheon Company. Laser beams cut through insulation on a wire without damaging conductive metal, because laser radiation that melts plastic insulation is reflected by the metal. The laser process is fast, clean, precise and repeatable. It eliminates quality control problems and the expense of rejected wiring.

  7. Reprint of “Performance analysis of a model-sized superconducting DC transmission system based VSC-HVDC transmission technologies using RTDS”

    NASA Astrophysics Data System (ADS)

    Dinh, Minh-Chau; Ju, Chang-Hyeon; Kim, Sung-Kyu; Kim, Jin-Geun; Park, Minwon; Yu, In-Keun

    2013-01-01

    The combination of a high temperature superconducting DC power cable and a voltage source converter based HVDC (VSC-HVDC) creates a new option for transmitting power with multiple collection and distribution points for long distance and bulk power transmissions. It offers some greater advantages compared with HVAC or conventional HVDC transmission systems, and it is well suited for the grid integration of renewable energy sources in existing distribution or transmission systems. For this reason, a superconducting DC transmission system based HVDC transmission technologies is planned to be set up in the Jeju power system, Korea. Before applying this system to a real power system on Jeju Island, system analysis should be performed through a real time test. In this paper, a model-sized superconducting VSC-HVDC system, which consists of a small model-sized VSC-HVDC connected to a 2 m YBCO HTS DC model cable, is implemented. The authors have performed the real-time simulation method that incorporates the model-sized superconducting VSC-HVDC system into the simulated Jeju power system using Real Time Digital Simulator (RTDS). The performance analysis of the superconducting VSC-HVDC systems has been verified by the proposed test platform and the results were discussed in detail.

  8. Design, analysis and limitations of a DC-to-AC converter usable for interface alternative energy sources and energy storage systems with the utility grid

    Microsoft Academic Search

    Ashim K. Chakravorti; Alexander E. Emanuel

    1993-01-01

    A DC-AC power converter design that can be used to interface any type of alternative energy source or energy storage system with the utility grid is presented. The converter is capable of real and reactive power exchanges between the utility grid and the alternative energy source(s). The control philosophy is very simple and allows for the synthesis of useful harmonics.

  9. Influence of the current control loops of DC arc furnaces on voltage fluctuations and harmonics in the HV power supply system

    Microsoft Academic Search

    D. Stade; H. Schau; St. Prinz

    2000-01-01

    It is necessary, to an increasing extent, to take controllers and control loops into consideration in mathematical modelling and simulations for power quality studies. DC arc furnaces belong to those electric loads which network behaviour is essentially influenced by control processes. Rated at more than 100 MVA, these furnaces cause voltage fluctuations and harmonics in the HV power system. Based

  10. A survey of the Pseudomonas syringae pv. tomato DC3000 type III secretion system effector repertoire reveals several effectors that are deleterious when expressed in Saccharomyces cerevisiae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The injection of nearly 30 effector proteins by the type III secretion system underlies the ability of Pseudomonas syringae pv. tomato strain DC3000 to cause disease in tomato and other host plants. The search for effector functions is complicated by redundancy within the repertoire and by plant R-g...

  11. GENOME-WIDE IDENTIFICATION OF PROTEINS SECRETED BY THE HRP TYPE III SECRETION SYSTEM OF PSEUDOMONAS SYRINGAE PV. TOMATO DC3000

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability of Pseudomonas syringae pv. tomato DC3000 to be pathogenic on plants is dependent on the Hrp type III protein secretion system and, collectively, the effector proteins translocated into plant cells. A genome wide search for Hrp effectors was performed based on patterns in the N terminal...

  12. A Practical Monitoring System for the Structural Safety of Mega-Trusses Using Wireless Vibrating Wire Strain Gauges

    PubMed Central

    Park, Hyo Seon; Lee, Hwan Young; Choi, Se Woon; Kim, Yousok

    2013-01-01

    Sensor technologies have been actively employed in structural health monitoring (SHM) to evaluate structural safety. To provide stable and real-time monitoring, a practical wireless sensor network system (WSNS) based on vibrating wire strain gauges (VWSGs) is proposed and applied to a building under construction. In this WSNS, the data measured from each VWSG are transmitted to the sensor node via a signal line and then transmitted to the master node through a short-range wireless communication module (operating on the Industrial, Scientific, and Medical (ISM) band). The master node also employs a long-range wireless communication module (Code Division Multiple Access—CDMA) to transmit the received data from the sensor node to a server located in a remote area, which enables a manager to examine the measured data in real time without any time or location restrictions. In this study, a total of 48 VWSGs, 14 sensor nodes, and seven master nodes were implemented to measure long-term strain variations of mega-trusses in an irregular large-scale building under construction. Based on strain data collected over a 16-month period, a quantitative evaluation of the construction process was performed to determine the aspects that exhibit the greatest influence on member behavior and to conduct a comparison with numerical simulation results. The effect of temperature stress on the structural elements was also analyzed. From these observations, the feasibility of a long-term WSNS based on VWSGs to evaluate the structural safety of an irregular building under construction was confirmed. PMID:24351640

  13. A practical monitoring system for the structural safety of mega-trusses using wireless vibrating wire strain gauges.

    PubMed

    Park, Hyo Seon; Lee, Hwan Young; Choi, Se Woon; Kim, Yousok

    2013-01-01

    Sensor technologies have been actively employed in structural health monitoring (SHM) to evaluate structural safety. To provide stable and real-time monitoring, a practical wireless sensor network system (WSNS) based on vibrating wire strain gauges (VWSGs) is proposed and applied to a building under construction. In this WSNS, the data measured from each VWSG are transmitted to the sensor node via a signal line and then transmitted to the master node through a short-range wireless communication module (operating on the Industrial, Scientific, and Medical (ISM) band). The master node also employs a long-range wireless communication module (Code Division Multiple Access-CDMA) to transmit the received data from the sensor node to a server located in a remote area, which enables a manager to examine the measured data in real time without any time or location restrictions. In this study, a total of 48 VWSGs, 14 sensor nodes, and seven master nodes were implemented to measure long-term strain variations of mega-trusses in an irregular large-scale building under construction. Based on strain data collected over a 16-month period, a quantitative evaluation of the construction process was performed to determine the aspects that exhibit the greatest influence on member behavior and to conduct a comparison with numerical simulation results. The effect of temperature stress on the structural elements was also analyzed. From these observations, the feasibility of a long-term WSNS based on VWSGs to evaluate the structural safety of an irregular building under construction was confirmed. PMID:24351640

  14. Modeling of D/C motor driven synthetic jet acutators for flow separation control

    E-print Network

    Balasubramanian, Ashwin Kumar

    2004-11-15

    The objective of this research is to present a theoretical study of the compressibility effects on the performance of an electric D/C motor driven synthetic jet actuator for flow separation control. Hot wire anemometer experiments were conducted...

  15. Seamless integration of 100-G wire line and 100-GHz wireless link system

    NASA Astrophysics Data System (ADS)

    Dong, Ze; Yu, Jianjun; Li, Xinying; Chi, Nan

    2013-01-01

    In this invited paper, we experimentally demonstrate a seamlessly integrated fiber-wireless system that delivers 108-Gb/s signal through 80-km fiber and 1-m wireless transport over free-space at 100 GHz, adopting polarization-divisionmultiplexing quadrature-phase-shift-keying (PDM-QPSK) modulation and heterodyning coherent detection. The X- and Y-polarization baseband components of the optical PDM-QPSK are simultaneously up-converted to 100-GHz wireless carriers by optical polarization-diversity heterodyne beating, and then independently transmitted and received by two pairs of transmitter and receiver antennas, which forms a 2x2 multiple-input multiple-output (MIMO) wireless link. At the wireless receiver, two-stage down conversion is performed with firstly done in analog domain based on balanced mixer and sinusoidal radio frequency (RF) signal, and then in digital domain based on digital signal processing (DSP). MIMO signal de-multiplexing combined with optical polarization multiplexing and free space MIMO crosstalk is realized by constant modulus algorithm (CMA) in digital signal processing (DSP) part at the receiver. The bit-error ratio (BER) for the 108-Gb/s PDM-QPSK signal is less than the pre-forward-error-correction (pre-FEC) threshold of 3.8x10-3 after both 1-m wireless delivery at 100 GHz and 80-km single-mode fiber-28 (SMF-28) transmission. To our knowledge, this is the first demonstration to realize 100-Gb/s signal delivery through both fiber and wireless links at 100GHz.

  16. Motion control of the accumulator flying wires

    SciTech Connect

    Wang, X.Q.

    1990-04-23

    Flying wire systems for the Fermilab Accumulator are being constructed in order to measure the transverse beam profiles during stacking. Each device passes a 25 micron carbon filament through the beam transversely at a constant velocity of 10 m/s. Collisions between the beam particles and the wire produce secondary particle cascades, which in turn produce photons in a scintillator. A photomultiplier tube is used to measure the light intensity while the wire position is determined by an optical encoder. There are six Accumulator flying wire systems. Four of them are to be used in normal stacking operation: two horizontal and two vertical flying wires are in the AP40 high dispersion section, covering the core orbit and the extraction orbit respectively. The other two horizontal wires are for measuring the momentum distribution of the beam on the central orbit at the Accumulator transition energy. At the AP40 high dispersion region a wire covers the central orbit, the other is in the AP30 low dispersion section. The operation and control of the flying wire system is discussed in this paper. 11 figs.

  17. Polarity Effect and Flow Characteristics of Wire-Rod Type Electrohydrodynamic Gas Pump

    Microsoft Academic Search

    B. Komeili; J. S. Chang; G. Harvel

    2006-01-01

    The electrohydrodynamic (EHD) flow characteristics for a wire to rod type EHD gas pump have been experimentally investigated. Experiments were conducted for DC negative and positive applied high voltage to a corona wire of diameter 0.24 mm from 0-24 kV, grounding rod electrode diameter from 1.5 mm to 3.1 mm and wire\\/rod electrode distance to pipe diameter ratio from 0.63

  18. This paper describes the energy consideration of fully wireless and mobile-wired sensor system and presented the prototype of

    E-print Network

    Halgamuge, Malka N.

    formation for randomly placed wireless sensors. Index Terms--LVDT, Data acquisition, Signal conditioning, RS of sensors can ensure that there is enough redundancy in data acquisition that quality of dataABSTRACT This paper describes the energy consideration of fully wireless and mobile-wired sensor

  19. A novel Pseudo PID algorithm of DC-DC converter

    Microsoft Academic Search

    Fengbin Peng; Qiang Liu; Zhiqiang Li

    2010-01-01

    A new DC-DC converter PWM (Pulse Width Modulation) algorithm is presented in this paper. In contrast to the conventional voltage-error-based PWM PI (Proportional-Integral) controller, inductor current controller is implemented as the derivative action of PID control to stabilize the dynamic behavior of the system. Back-Propagation neural network (BPNN) is applied to optimize the Pseudo PID parameters. A boost converter is

  20. Internet based toolkit for simulation of DC\\/DC converters

    Microsoft Academic Search

    Sevki Demirbas; Gulrkan Mutlu

    2011-01-01

    Ab stract- In this study, a simulation toolkit for buck, boost and buck-boost DC\\/DC converters has been implemented. By using developed software, users can be connected to the system from any computer having internet connection and can be perform the experiments. The simulation toolkit has been realized with Matlab&Simulink and LabVIEW software. Matlab&Simulink has been used for simulation of the

  1. Health care's 100 most wired.

    PubMed

    Solovy, A; Serb, C

    1999-02-01

    They're wired all right, and America's 100 most techno-savvy hospitals and health systems share one more thing: a commitment to using technology to link with employees, patients, suppliers, and insurers. "We want to be a health care travel agency for our community," says one chief information officer. "And we see Internet technology as a key." PMID:10081454

  2. High current DC choppers and their operational benefits

    Microsoft Academic Search

    V. Scaini; B. M. Urban

    1998-01-01

    The availability in recent years of larger power switching devices has brought about the development of larger power electronic circuits. These circuits were previously used in lower power applications. One such circuit is the DC-to-DC power converter, otherwise known as a DC chopper. The DC chopper system has many operational benefits over conventional diode or thyristor rectifiers, such as: low

  3. Feasibility study of high frequency step-up transformer linked soft-switching PWM DC-DC converter with tapped inductor filter

    Microsoft Academic Search

    S. Moisseev; K. Suzuoka; T. Ahmed; M. Nakaoka

    2003-01-01

    This paper presents a novel high frequency transformer linked full-bridge type soft-switching phase-shift PWM control DC-DC power converter, which can be used as DC power conditioner for small-scale fuel cell power generation system as well as isolated step-up DC-DC power converter for automotive AC power supply. Using full-bridge soft-switching PWM DC-DC converter topology makes possible to use low voltage high

  4. First-order perturbation solutions of embedded strained wires

    Microsoft Academic Search

    C.-H. Chiu; Hangyao Wang

    2006-01-01

    The paper presents the first-order perturbation solutions to the two-dimensional elasticity problems of strained wires embedded in a multilayered film-substrate system with homogeneous elastic properties. The solutions are accurate to the first order of the characteristic slope of the wires; the expressions of the solutions are concise for wires containing multiple facets; and the solutions are valid for single wire,

  5. Imaging electrostatic microconstrictions in long 1D wires

    Microsoft Academic Search

    R. Crook; C. G. Smith; M. Y. Simmons; D. A. Ritchie

    2002-01-01

    We present scanned gate microscopy (SGM) images of a 4mum long one-dimensional (1D) wire. The wire was defined by split-gate surface electrodes over a GaAs\\/AlGaAs heterostructure incorporating a subsurface 2D electron system. To generate SGM images, a charged tip scans a rectangular region over the wire. The wire conductance is recorded to determine the image contrast. A chain of circular

  6. Imaging electrostatic microconstrictions in long 1D wires

    Microsoft Academic Search

    R Crook; C. G Smith; M. Y Simmons; D. A Ritchie

    2002-01-01

    We present scanned gate microscopy (SGM) images of a 4?m long one-dimensional (1D) wire. The wire was defined by split-gate surface electrodes over a GaAs\\/AlGaAs heterostructure incorporating a subsurface 2D electron system. To generate SGM images, a charged tip scans a rectangular region over the wire. The wire conductance is recorded to determine the image contrast. A chain of circular

  7. A converter-type magnetometer using amorphous ribbon or wire

    Microsoft Academic Search

    Marek Z. Kozak; Eugeniusz Misiuk; Waldemar Kwiatkowski

    1991-01-01

    The accurate and quick-response magnetometer presented here is composed of a resonant circuit with an amorphous core, an operational amplifier, and a voltage-current converter. Nonmagnetostrictive amorphous ribbons or wires are used in the straight form for sensing strength and direction of the dc magnetic field. The range having good linearity strongly depends on the converter current and the demagnetizing field

  8. 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.

  9. Implicit Model Predictive Control of a Full Bridge DC–DC Converter

    Microsoft Academic Search

    Yanhui Xie; Reza Ghaemi; Jing Sun; James S. Freudenberg

    2009-01-01

    This paper presents a model predictive control (MPC)-based approach for a full bridge dc-dc converter of a fuel cell power system. The objective of the proposed control algorithm is to regulate the output voltage without violating the peak current constraint. We first develop a large signal dynamic model for the full bridge dc-dc converter. The peak current protection requirement is

  10. Transformer-Coupled Multiport ZVS Bidirectional DC–DC Converter With Wide Input Range

    Microsoft Academic Search

    Haimin Tao; Andrew Kotsopoulos; Jorge L. Duarte; Marcel A. M. Hendrix

    2008-01-01

    Multiport dc-dc converters are particularly interesting for sustainable energy generation systems where diverse sources and storage elements are to be integrated. This paper presents a zero-voltage switching (ZVS) three-port bidirectional dc-dc converter. A simple and effective duty ratio control method is proposed to extend the ZVS operating range when input voltages vary widely. Soft-switching conditions over the full operating range

  11. Discrete-time modeling of multi-state DC-DC converters

    Microsoft Academic Search

    Mummadi Veerachary; Ramakanth Naidu Gowra; Dileep Ganta

    2010-01-01

    The discrete-time models obtained from state-space average models are accurate only in the low frequency region and are not suitable for predicting the high frequency behavior. This limitation becomes more severe particularly in the multi-state dc-dc converters. To improve the accuracy the discrete-time models applicable for multi-state dc-dc converters are developed in this paper. To enhance the closed-loop converter system

  12. Current sharing of paralleled DC-DC converters using GA-based PID controllers

    Microsoft Academic Search

    Chin-hsing Cheng; Po-jen Cheng; Ming-jia Xie

    2010-01-01

    We demonstrate a concept for pulse-width modulation (PWM) control of a parallel DC–DC buck converter, which eliminates the need for multiple physical connections of gating\\/PWM signals among the distributed converter modules. The proposed control concept may lead to easier distributed control implementation of parallel DC–DC converters and distributed power systems.For equipment with significant power requirement, the traditional single power supply

  13. Comparing DC-DC converters for power management in hybrid electric vehicles

    Microsoft Academic Search

    R. M. Schupbach; J. C. Balda

    2003-01-01

    The design of DC-DC converters for power electronic interfaces in power management systems for hybrid electric vehicle (HEV) is a very challenging task. To this end, this paper presents an analysis, design, and comparison study of several bi-directional non-isolated DC-DC converter topologies that could be considered potential candidates for the power electronic interface of HEV energy\\/power sources, in particular an

  14. New step-up DC\\/DC converter with high-frequency isolation

    Microsoft Academic Search

    Dmitri Vinnikov; Indrek Roasto; Tanel Jalakas

    2009-01-01

    This paper presents a new step-up DC\\/DC converter topology with high-frequency isolation intended for residential fuel cell power systems. In contrast to traditional voltage source converters, the proposed topology utilizes the impedance network represented by a combination of two inductors and two capacitors on the input side of the DC\\/DC converter. Due to the specific feature of boosting input voltage

  15. AC and DC power transmission

    SciTech Connect

    Not Available

    1985-01-01

    The technical and economic assessment of AC and DC transmission systems; long distance transmission, cable transmission, system inter-connection, voltage support, reactive compensation, stabilisation of systems; parallel operation of DC links with AC systems; comparison between alternatives for particular schemes. Design and application equipment: design, testing and application of equipment for HVDC, series and shunt static compensated AC schemes, including associated controls. Installations: overall design of stations and conductor arrangements for HVDC, series and shunt static AC schemes including insulation co-ordination. System analysis and modelling.

  16. The design on Adaptive Front Lighting System (AFS) based on brushless DC motor

    Microsoft Academic Search

    Xu pingping; Song jianguo; Shen Guangdi

    2008-01-01

    Adaptive front lighting system(AFS) is most advanced vehicle lighting system, which can greatly reduce driverpsilas fatigue degree when driving on curve road at night, make driver clearly see actual road surface at turn around, make driver have abundant time to deal with emergency, and evidently promote safety at night. Most high class vehicles have been fixed AFS in Japan, meanwhile

  17. Conditions for saddle-node bifurcations in AC\\/DC power systems

    Microsoft Academic Search

    C. A Cañizares

    1995-01-01

    Saddle-node bifurcations are dynamic instabilities of differential equation models that have been associated with voltage collapse problems in power systems. This paper presents the conditions needed for detecting these types of bifurcations using power flow equations for a dynamic model of ACIDC systems, represented by differential equations and algebraic constraints. Two methods typically used to detect saddle-node bifurcations, namely, direct

  18. VOLTAGE COLLAPSE AND TRANSIENT ENERGY FUNCTION ANALYSES OF AC\\/DC SYSTEMS

    Microsoft Academic Search

    Claudio A. Canizares

    1991-01-01

    Abstract This thesis presents a thorough analysis of saddle-node bifurcations for power system dynamic models, including a third order representation of high voltage direct current (HVDC) transmission, classic ac generator dynamics with reactive flows, and volt- age and frequency dependent load models. Extensions of the Point of Collapse and Continuation methods, initially used in ac system voltage stability studies, are

  19. A system for generating a stable d.c. baseline and suppressing noise when processing pulsed signals of physiological and other origin

    Microsoft Academic Search

    Clifford D. Ferris

    1966-01-01

    In the processing of pulsed electrical signals of physiological origin (as well as signals from other sources), it is desirable\\u000a to be able to provide a stable d.c. baseline and to suppress noise. This paper examines various design considerations for\\u000a such a system and presents the complete electrical schematic for one design. Photographs of system performance are included.

  20. Digital Control Technologies for Modular DC-DC Converters

    NASA Technical Reports Server (NTRS)

    Button, Robert M.; Kascak, Peter E.; Lebron-Velilla, Ramon

    2002-01-01

    Recent trends in aerospace Power Management and Distribution (PMAD) systems focus on using commercial off-the-shelf (COTS) components as standard building blocks. This move to more modular designs has been driven by a desire to reduce costs and development times, but is also due to the impressive power density and efficiency numbers achieved by today's commercial DC-DC converters. However, the PMAD designer quickly learns of the hidden "costs" of using COTS converters. The most significant cost is the required addition of external input filters to meet strict electromagnetic interference (MIAMI) requirements for space systems. In fact, the high power density numbers achieved by the commercial manufacturers are greatly due to the lack of necessary input filters included in the COTS module. The NASA Glenn Research Center is currently pursuing a digital control technology that addresses this problem with modular DC-DC converters. This paper presents the digital control technologies that have been developed to greatly reduce the input filter requirements for paralleled, modular DC-DC converters. Initial test result show that the input filter's inductor size was reduced by 75 percent, and the capacitor size was reduced by 94 percent while maintaining the same power quality specifications.

  1. Hydrogen Storage Systems Analysis Working Group Meeting Argonne National Laboratory DC Offices

    E-print Network

    , including physical processes and kinetics, and an overall system model for the hydrogen fuel cell vehicle of solid ammonia borane for hydrogen storage. Rajesh Ahluwalia (ANL) discussed the results of analyzing

  2. High-voltage (270 V) dc power-generating system for fighter aircraft

    NASA Technical Reports Server (NTRS)

    Mcginley, K. M.

    1983-01-01

    The advantages of using high voltage, direct current advanced power generating systems in fighter aircraft are discussed. Weight reduction is achieved. Efficiency is increased 85 to 90 percent by eliminating the constant speed drive. Power interruptions are eliminated. There are no speed restrictions and no powerline constraints. Personal safety is increased by eliminating the hold on frequency, present in ac systems, which causes muscle contractions.

  3. Organic light-emitting diode on indium zinc oxide film prepared by ion assisted deposition dc sputtering system

    Microsoft Academic Search

    W. J Lee; Y.-K Fang; J.-J Ho; C.-Y Chen; L.-H Chiou; S.-J Wang; F Dai; T Hsieh; R.-Y Tsai; D Huang; F. C Ho

    2002-01-01

    In this letter, high-quality indium zinc oxide (IZO) films (60–220 nm) were first grown on hardness poly-carbonate substrate by ion-assisted deposition (IAD) dc magnetron sputtering without a post deposition annealing treatment. The electrical, optical, and structural properties of these films were investigated as a function of film thickness. IAD dc magnetron sputtering provides very uniform IZO films with high transparency

  4. Study of overhead ground-wire shunting rates during grounding failure, for 500 kV substation grounding system design

    Microsoft Academic Search

    H. Makino; H. Itakura

    1999-01-01

    Ensuring the prescribed grounding resistance for 500 kV substations has become difficult due to various factors including increased short-circuit capacity, reduction of substation area, and construction of substations in mountainous locations, making it necessary to drive electrodes deep into the ground at high cost. To find a solution to this problem, we reviewed overhead ground-wire shunting rates during grounding failure,

  5. Current Harmonics Cancellation in Three-Phase Four-Wire Systems by Using a Four-Branch Star Filtering Topology

    Microsoft Academic Search

    Pedro RodrÍguez; J. Ignacio Candela; Alvaro Luna; Lucian Asiminoaei; Remus Teodorescu; Frede Blaabjerg

    2009-01-01

    This paper presents a new solution for filtering current harmonics in three-phase four-wire networks. The original four-branch star (FBS) filter topology presented in this paper is characterized by a particular layout of single-phase inductances and capacitors, without using any transformer or special electromagnetic device. Via this layout, a power filter, with two different and simultaneous resonance frequencies and sequences, is

  6. Developing Process of Positive Creeping Discharge along Aerial Insulated Wire

    NASA Astrophysics Data System (ADS)

    Nishi, Toshiyuki; Hanaoka, Ryoichi; Takata, Shinzo

    In high voltage aerial distribution systems, the insulated wires are supported by the insulator with the binding wire at the electric light pole. When a lightning strike happened in the neighborhood of the aerial insulated wire in a power distribution system, the inductive lightning surges invade to the central line of the wire. Then, the creeping discharges develop along the wire surface from the binding wire tip in the same time as the flashover of the insulator at a supporting point of the wire. If the wire insulator has weak points such as the pin-holes, the disaster near the wire supporting point may occur with a melting of wire due to the punch-through breakdown. To prevent such accidents, it is important to clarify the mechanism of the creeping discharge along the insulated wire which caused by the lightning strike. The polarity of creeping discharges is decided by the polarity of inductive lightning surges, and the developing length and aspect of the discharge are greatly different by the discharge polarity. The developing of these creeping discharges is attributed to complicated behaviors of the positive and negative electric charges. In the present study, we examined in detail the developing process of positive creeping discharge along the wire surface by using a high speed image converter camera. This paper describes the developing mechanism of positive creeping discharge based on the experimental results.

  7. Lingual straight wire method.

    PubMed

    Takemoto, Kyoto; Scuzzo, Giuseppe; Lombardo, L U C A; Takemoto, Y U I

    2009-12-01

    The mushroom arch-wire is mainly used in lingual orthodontic treatment but the complicated wire bending it requires affects both the treatment results and the time spent at the chair. The author proposes a new lingual straight wire method (LSW) in order to facilitate arch coordination and simplify the mechanics. The attention paid to the set-up model and bracket positioning and bonding plus the use of the new LSW method will also improve patient comfort. PMID:20303920

  8. Sintered wire annode

    DOEpatents

    Falce, Louis R. (Surprise, AZ); Ives, R. Lawrence (Saratoga, CA)

    2007-12-25

    A plurality of high atomic number wires are sintered together to form a porous rod that is parted into porous disks which will be used as x-ray targets. A thermally conductive material is introduced into the pores of the rod, and when a stream of electrons impinges on the sintered wire target and generates x-rays, the heat generated by the impinging x-rays is removed by the thermally conductive material interspersed in the pores of the wires.

  9. The Use of Software Agents for Autonomous Control of a DC Space Power System

    NASA Technical Reports Server (NTRS)

    May, Ryan D.; Loparo, Kenneth A.

    2014-01-01

    In order to enable manned deep-space missions, the spacecraft must be controlled autonomously using on-board algorithms. A control architecture is proposed to enable this autonomous operation for an spacecraft electric power system and then implemented using a highly distributed network of software agents. These agents collaborate and compete with each other in order to implement each of the control functions. A subset of this control architecture is tested against a steadystate power system simulation and found to be able to solve a constrained optimization problem with competing objectives using only local information.

  10. Improved dynamic security assessment for AC\\/DC power systems using transient energy functions

    Microsoft Academic Search

    Nilkamal Fernandopulle

    2006-01-01

    Due to rapid changes in electricity demand and disturbances caused by faults and equipment switching, power systems are often in a state of change. A method to predict transient stability that can accurately process a range of conditions frequently and faster than time simulation is highly advantageous. The Transient Energy Function (TEF) method is such a tool for this purpose.

  11. A System for Speed and Torque Control of DC Motors with Application to Small Snake Robots

    E-print Network

    Simaan, Nabil

    subtasks such as suturing vocal fold tissue. This clinical problem motivated the development of a novel's are mounted on a Rotating Base Unit (RBU), permitting the system to be oriented within the throat so as to minimize collisions between DDU holders. The DDU holders are thin tubes (about 4 mm in outside diameter

  12. 1998 wire development workshop proceedings

    SciTech Connect

    NONE

    1998-04-01

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development.

  13. Precise DC current sensors

    Microsoft Academic Search

    P. Ripka; P. Kejik; P. Kaspar; K. Draxler

    1996-01-01

    Three novel DC current sensors are described. Portable 40 A DC current clamps have resolution of 1 mA and high immunity to unclamped currents and external fields. AC\\/DC comparator with amorphous core may serve for precise measurement of DC currents with AC component up to 1 kHz. Magnetoresistive sensor field has limited accuracy but potential bandwidth from DC to 1

  14. Effect of relative humidity on electron distribution and ozone production by DC coronas in air

    Microsoft Academic Search

    Junhong Chen; Pengxiang Wang

    2005-01-01

    The effect of relative humidity on the electron distribution and the ozone production in the direct current (dc) corona discharge from a thin wire is evaluated with a numerical model. The model is based on the prior models of ozone production by dc coronas in dry air, with modifications to incorporate the effect of water vapor on the corona plasma

  15. Effect of relative humidity on electron distribution and ozone production by DC coronas in air

    Microsoft Academic Search

    Junhong Chen; Pengxiang Wang

    2004-01-01

    Summary form only given. A numerical model of electron distribution and ozone production in clean and humid air by DC corona discharges from a thin wire is presented. The model is based on the prior models of ozone production by DC coronas in dry air, with modifications to incorporate the effect of water vapor on the electrical characteristics and the

  16. Nano-storage wires.

    PubMed

    Lee, Dong Jun; Kim, Eunji; Kim, Daesan; Park, Juhun; Hong, Seunghun

    2013-08-27

    We report the development of "nano-storage wires" (NSWs), which can store chemical species and release them at a desired moment via external electrical stimuli. Here, using the electrodeposition process through an anodized aluminum oxide template, we fabricated multisegmented nanowires composed of a polypyrrole segment containing adenosine triphosphate (ATP) molecules, a ferromagnetic nickel segment, and a conductive gold segment. Upon the application of a negative bias voltage, the NSWs released ATP molecules for the control of motor protein activities. Furthermore, NSWs can be printed onto various substrates including flexible or three-dimensional structured substrates by direct writing or magnetic manipulation strategies to build versatile chemical storage devices. Since our strategy provides a means to store and release chemical species in a controlled manner, it should open up various applications such as drug delivery systems and biochips for the controlled release of chemicals. PMID:23859333

  17. Tracking with wire chambers at the SSC

    SciTech Connect

    Hanson, G.G.; Gundy, M.C.; Palounek, A.P.T.

    1989-07-01

    Limitations placed on wire chambers by radiation damage and rate requirements in the SSC environment are reviewed. Possible conceptual designs for wire chamber tacking systems that meet these requirements are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 13 refs., 11 fig., 1 tab.

  18. Coulomb drag between quantum wires

    NASA Astrophysics Data System (ADS)

    Klesse, Rochus; Stern, Ady

    2000-12-01

    We study Coulomb drag in a pair of parallel one-dimensional electron systems within the framework of the Tomonaga-Luttinger model. We find that Coulomb coupling has a much stronger effect on one-dimensional wires than on two-dimensional layers: At zero temperature the transresistivity diverges, due to the formation of locked charge density waves. At temperature well above a crossover temperature T* the transresistivity follows a power law ?~Tx, where the interaction-strength dependent exponent x is determined by the Luttinger liquid parameter Kc- of the relative charge mode. At temperature below T* relative charge displacements are enabled by solitonic excitations, reflected by an exponential temperature dependence. The crossover temperature T* depends sensitively on the wire width, interwire distance, Fermi wavelength and the effective Bohr radius. For wire distances d¯>>k-1F it is exponentially suppressed with T*/EF~exp[-d¯kF/(1-Kc-)]. The behavior changes drastically if each of the two wires develop spin gaps. In this case we find that the transresistivity vanishes at zero temperature. We discuss our results in view of possible experimental realizations in GaAs-AlxGa1-xAs semiconductor structures.

  19. Three-dimensional modelling of a dc arc plasma in a twin-torch system

    NASA Astrophysics Data System (ADS)

    Tang, K. M.; Yan, J. D.; Chapman, C.; Fang, M. T. C.

    2010-09-01

    A three-dimensional steady-state arc model has been developed for simulating the behaviour of a twin-torch plasma system operating in an atmospheric argon environment. The governing equations for plasma flow, electric and magnetic fields are solved in a Cartesian coordinate system with suitable domain size and appropriate boundary conditions. Radiation from the arc is accounted for using the concept of net emission coefficient. Results over the current range 300-900 A suggest that the two arc columns attached, respectively, to anode and cathode are coupled by a thin tissue-like conducting layer with a thickness in the range 3-6 mm, serving as a critical part of the current path. Lorentz force resulting from the arc's current interacting with its own magnetic field plays a decisive role in bending the two arc columns and shaping the coupling zone. Turbulence is introduced to account for the effect resulting from instability of the coupling zone as observed in experiment and its effectiveness is analysed in detail using different length scale parameters. Suggestions to further improve the model are proposed.

  20. A new feedforward compensation to reject Dc-link voltage ripple in bi-directional Z-Source inverter ASD system

    Microsoft Academic Search

    Xinping Ding; Zhaoming Qian; Shuitao Yang; Fangzheng Peng

    2008-01-01

    A feedforward compensator applied in Z-source inverter ASD system has been presented. With this technique a constant peak dc-link voltage can be achieved with an excellent transient performance which enhances the rejection of input voltage ripple, and have good ride- through for voltage-sags. The effect of six pulse input voltage ripple which result from front-end diode rectifier has been described

  1. Comparison of the Initial Orthodontic Force Systems Produced by a New Lingual Bracket System and a Straight-Wire Appliance

    Microsoft Academic Search

    Lars-Michael Fuck; Dirk Wiechmann; Dieter Drescher

    2005-01-01

    Background and Aim: Over the last few years, lingual appliances have become an established orthodontic treatment technique. Many studies have concentrated on various esthetic aspects, on laboratory and clinical procedures, and on patient comfort and compliance. The orthodontic force systems of these appliances, however, have not yet been investigated. The aim of this study was thus to determine the forces

  2. How to Make a Simple DC Motor Equipment Needed

    E-print Network

    Barrash, Warren

    How to Make a Simple DC Motor Equipment Needed: A `D' size 1.5 V battery A magnet A piece off the outer coating, if scraped off at the wrong side the motor will not work. Very important when the position of the wire is like the one shown to the right. This will create a magnetic pole

  3. Model of Ozone Production in the DC Corona Discharge

    Microsoft Academic Search

    Junhong Chen; Jane Davidson

    2002-01-01

    A comprehensive numerical model of ozone production in clean, dry air by DC corona discharges is presented. This model combines a first-principle corona plasma model with a chemistry and 2-D transport model to obtain the distributions of ozone and other gaseous products in the neighborhood of a corona discharge wire. Electron number density distribution is obtained by solving the continuity

  4. A method to determine the sweep resistance of wire bonds for microelectronic packaging

    Microsoft Academic Search

    Huang-Kuang Kung; Yun-Ping Sun; Jeng-Nan Lee; Hung-Shyong Chen

    2008-01-01

    Many kinds of gold wire and bond profiles have been used in wire bonding technology. To date, no solid experimental results have been available to guide the bond designer in the choice of a better looping system. A method is proposed for evaluating the sweep resistance of wire bonds during the transfer molding process. The wire sweep method was developed

  5. NASA requirements and applications environments for electrical power wiring

    NASA Technical Reports Server (NTRS)

    Stavnes, Mark W.; Hammoud, Ahmad N.

    1992-01-01

    Serious problems can occur from insulation failures in the wiring harnesses of aerospace vehicles. In most recorded incidents, the failures have been identified to be the result of arc tracking, the propagation of an arc along wiring bundles through degradation of insulation. Propagation of the arc can lead to the loss of the entire wiring harness and the functions which it supports. While an extensive database of testing for arc track resistant wire insulations has been developed for aircraft applications, the counterpart requirements for spacecraft are very limited. The electrical, thermal, mechanical, chemical, and operational requirements for specification and testing of candidate wiring systems for spacecraft applications is presented.

  6. Energy gap and proximity effect in MgB2 superconducting wires R. Prozorov* and R. W. Giannetta

    E-print Network

    Prozorov, Ruslan

    of the penetration depth (T,H) in the presence of a dc magnetic field were performed in MgB2 wires. In as-prepared wires (T,H 130 Oe) shows a strong diamagnetic downturn below 10 K. A dc magnetic field of 130 Oe in a box furnace at 950 °C for approxi- mately 2 h. The reaction ampoule was then removed from the furnace

  7. DC/DC Converter Stability Testing Study

    NASA Technical Reports Server (NTRS)

    Wang, Bright L.

    2008-01-01

    This report presents study results on hybrid DC/DC converter stability testing methods. An input impedance measurement method and a gain/phase margin measurement method were evaluated to be effective to determine front-end oscillation and feedback loop oscillation. In particular, certain channel power levels of converter input noises have been found to have high degree correlation with the gain/phase margins. It becomes a potential new method to evaluate stability levels of all type of DC/DC converters by utilizing the spectral analysis on converter input noises.

  8. Wire Weight with Housing

    USGS Multimedia Gallery

    Wire weight is lowered to water surface to measure stage at a site. Levels are made to the wire weights elevation from known benchmarks to ensure correct readings. In the background there is housing protected with dikes along the Missouri River in Mandan, ND....

  9. PBGA wire bonding development

    Microsoft Academic Search

    W. K. Shu

    1996-01-01

    In a PBGA package, the existence of a glass transition temperature of 170~215°C for PCB substrate puts an upper ceiling to the usable wire bond temperature. The low thermal conductivity of PCB substrate and the need for a thicker material make fine pad pitch wire bonding even more difficult to do. To compensate for the limitation in thermal energy, high

  10. Transport in partially equilibrated inhomogeneous quantum wires.

    SciTech Connect

    Levchenko, A.; Micklitz, T.; Rech, J.; Matveev, K. A.; Materials Science Division; Freie Univ. Berlin; Centre de Physique Theorique

    2010-01-01

    We study transport properties of weakly interacting one-dimensional electron systems including on an equal footing thermal equilibration due to three-particle collisions and the effects of large-scale inhomogeneities. We show that equilibration in an inhomogeneous quantum wire is characterized by the competition of interaction processes which reduce the electrons total momentum and such which change the number of right- and left-moving electrons. We find that the combined effect of interactions and inhomogeneities can dramatically increase the resistance of the wire. In addition, we find that the interactions strongly affect the thermoelectric properties of inhomogeneous wires and calculate their thermal conductance, thermopower, and Peltier coefficient.

  11. Theory of the conductance of interacting quantum wires with good contacts and applications to carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Sedlmayr, Nicholas; Adam, Pia; Sirker, Jesko

    2013-01-01

    Using bosonization we derive the dc conductance G(L,T) of an interacting quantum wire with good contacts including current relaxing backscattering and umklapp processes. Our result yields the dependence of the conductance on length L and temperature T in the energy range where the Luttinger model is applicable. For a system where only a part of the current is protected by a conservation law, we surprisingly find an unreduced ideal quantum conductance as for a fully ballistic wire. As a second application, we calculate the conductance of metallic single-wall carbon nanotubes in an energy range where backscattering due to phonons dominates. In contrast to previous studies, we treat the electrons as interacting by using the Luttinger liquid formulation. The obtained results for the scaling of the dc conductance with temperature and length are compared with experimental data and yield a better description than the previously used noninteracting theory. Possible reasons for the remaining discrepancies in the temperature dependence between theory and experiment are discussed.

  12. Wire tension versus wire frequency: an experimental Ilizarov frame study.

    PubMed

    La Russa, Valentina; Skallerud, Bjørn; Klaksvik, Jomar; Foss, Olav A

    2010-08-26

    Stability of an Ilizarov frame highly depends on maintenance of adequate tension in the wires. Wire tension should be measured accurately in experimental laboratory studies when new types of wire fixators are tested. In this study, 20 wires were tested using two different wire fixators. The wires were sequentially tensioned from 0 to 1275 N in 50 N intervals. For each tension value, corresponding vibration frequency was recorded. We then described the relationship between wire tension and wire vibration frequency in an empirical equation (R(2)=99.8). Wire vibration frequency can also be described theoretically by the Euler-Bernoulli equation for a thin beam. Theoretical frequencies were calculated and compared with corresponding experimental frequencies. A close agreement was found (95% limits of agreement, +/-3.2 Hz). This empirical equation represents a simple tool, applicable when investigating the effect of new wire fixators, pre-tensioning and frame constructions on wire tension. PMID:20472242

  13. Qualitative comparison of calculated turbulence responses with wind-tunnel measurements for a DC-10 derivative wing with an active control system

    NASA Technical Reports Server (NTRS)

    Perry, B., III

    1981-01-01

    This paper presents comparisons of analytically-predicted and experimental turbulence responses of a wind-tunnel model of a DC-10 derivative wing equipped with an active control system. The active control system was designed for the purpose of flutter suppression, but it had the additional benefit of alleviating gust loads (wing bending moment) by about 25 percent. Comparisons of various wing responses are presented for variations in active-control-system parameters and tunnel speed. The analytical turbulence responses were obtained using DYLOFLEX, a computer program for dynamic loads analyses of flexible airplanes with active controls. In general, the analytical predictions agreed reasonably well with the experimental data.

  14. Qualitative comparison of calculated turbulence responses with wind-tunnel measurements for a DC-10 derivative wing with an active control system

    NASA Technical Reports Server (NTRS)

    Perry, B., III

    1981-01-01

    Comparisons are presented analytically predicted and experimental turbulence responses of a wind tunnel model of a DC-10 derivative wing equipped with an active control system. The active control system was designed for the purpose of flutter suppression, but it had additional benefit of alleviating gust loads (wing bending moment) by about 25%. Comparisions of various wing responses are presented for variations in active control system parameters and tunnel speed. The analytical turbulence responses were obtained using DYLOFLEX, a computer program for dynamic loads analyses of flexible airplanes with active controls. In general, the analytical predictions agreed reasonably well with the experimental data.

  15. Artificial neural network based permanent magnet DC motor drives

    SciTech Connect

    Hoque, M.A. Zaman, M.R.; Rahman, M.A. [Memorial Univ. of Newfoundland, St. John`s, Newfoundland (Canada). Faculty of Engineering and Applied Science

    1995-12-31

    A novel scheme for the speed control of a permanent magnet (PM) dc motor drive incorporating artificial neural network (ANN) is proposed. The drive system includes an ANN speed controller, micro-processor based dc-dc converter and a laboratory PM dc motor. A multi-layer artificial neural network structure with a feedback loop is designed in order to precisely operate the control circuit for the dc-dc converter. The complete drive system is simulated and implemented in real time. Both the simulation and experimental results prove the inherent capability of the ANN which makes it possible to maintain desired speed control in the presence of parameter variations and load disturbances. The performances of the ANN based PM dc drive system are compared with the simulated results of the conventionally controlled drive system. This clearly indicates the better performance of the ANN based PM dc motor drive system, particularly in case of parameter and load variations.

  16. 30 CFR 75.1003 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Mineral Resources 1 2011-07-01 2011-07-01 false Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 75.1003 Section 75.1003 Mineral...

  17. 30 CFR 75.1003 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Mineral Resources 1 2010-07-01 2010-07-01 false Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 75.1003 Section 75.1003 Mineral...

  18. 30 CFR 77.1802 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Mineral Resources 1 2011-07-01 2011-07-01 false Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 77.1802 Section 77.1802 Mineral...

  19. 30 CFR 77.1802 - Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Mineral Resources 1 2010-07-01 2010-07-01 false Insulation of trolley wires, trolley feeder wires and bare signal wires; guarding of trolley wires and trolley feeder wires. 77.1802 Section 77.1802 Mineral...

  20. USERDA Division of Electric Energy Systems dc superconducting power transmission line project at LASL. Progress report No. 15, October 1, 1975September 30, 1976. [100kV, 5 GW dc

    Microsoft Academic Search

    F. J. Edeskuty; P. Chowdhuri

    1977-01-01

    This annual progress report of the Los Alamos Scientific Laboratory dc Superconducting Power Transmission Line (SPTL) Development Project covers the period October 1975 to September 1976. Progress in the electrical, cryogenic, and superconductor design for a 100-kV, 5-GW dc SPTL is described.