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The ZVS-PWM commutation cell applied to the DC-AC converter

IEEE TRANSACTIONS ON POWER ELECTRONICS 1997年第4期12卷 726-733页

作者： deSeixas, FJM Martins, DC UNIV FED SANTA CATARINA CTCEELINEPBR-88010970 FLORIANOPOLISSCBRAZIL

This paper presents the analysis of a dc-ac converter using a zero-voltage-switching (ZVS) commutation cell. First, we show the cell applied to the buck converter. The stages of operation are presented along with the main current and voltage equations. Next, we adapt the converter to the regenerative-operation mode. Hence, the full-bridge converter at low-frequency operation is connected in the de-de output stage (at high frequency). The main switches commute at zero voltage. The converter operated at constant frequency with pulse-width modulation (PWM), and neither overvoltage nor additional current stress was observed by digital simulation. A design example and experimental results obtained by prototype, rated at 275 and 1 kW, are also presented.

关键词： DC-AC converter power electronics pulse-width modulation soft switching

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Inverter harmonic reduction using Walsh function harmonic elimination method

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IEEE TRANSACTIONS ON POWER ELECTRONICS 1997年第6期12卷 971-982页

作者： Liang, TJ OConnell, RM Hoft, RG UNIV MISSOURI DEPT ELECT ENGNCOLUMBIAMO 65211

A pulse-width-modulated (PWM) inverter using the Walsh function harmonic elimination method is proposed in this paper. By using the Walsh domain waveform analytic technique, the harmonic amplitudes of the inverter output voltage can be expressed as functions of switching angles. Thus, the switching angles are optimized by solving linear algebraic equations instead of solving nonlinear transcendental equations. The local piecewise linear relations between the switching angles and the fundamental amplitude can be obtained under an appropriate initial condition. By searching all feasible initial conditions, the global solutions are obtained. The relations between switching angles and fundamental amplitude can be approximated by straight-line curve fitting. Thus, on-line control of fundamental amplitude and frequency is possible for the microcomputer-based implementation. The developed algorithm can be applied to both bipolar and unipolar switching schemes. The theoretical predictions are confirmed by computer simulations and DSP-based hardware implementation.

关键词： harmonic elimination inverter pulse-width modulation Walsh function

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Using the Functionality of PWM Inverters for Fault Diagnosis of Induction Motors

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IFAC Proceedings Volumes 1997年第18期30卷 247-252页

作者： J. Beilharz D. Filbert Technische Universität Berlin Institut für Meβ- und Automatisierungstechnik Einsteinufer 19 10587 Berlin Germany Phone: +49 30 314-24893 Fax: +49 30 314-25717 Phone: +49 30 314-22280 Fax: +49 30 314-25717

Conventional parameter identification methods for induction motors are based on linear steady state models. Identifiability of rotor parameters can be critical due to small currents flowing in the rotor. With modern pulse-width modulated (PWM) inverters it is possible to create arbitrary test signals for the identification process. The integration of a voltage source inverter in the diagnostic process is stressed. Theoretical background on appropriate modeling is given. Finally, comments are made on measurement results of a laboratory benchmark stand comprising a 370 W induction machine and a three-phase PWM voltage source inverter

关键词： Fault identification Induction motor Inverter pulse-width modulation Dual frequency excitation Microprocessor

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Control Performance of Small-Sized PWM Pneumatic Servo

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IFAC Proceedings Volumes 1997年第6期30卷 913-918页

作者： Toshiro Noritsugu Norio Kataoka Faculty of Engineering. Okayama University 3-1-1 Tsushimanaka Okayama 700 Japan TEL +81-86-251-8061 FAX +81-86-255-9669

A driving of small-sized machines is one of the most effective applications of a pneumatic actuator. This study investigates the fundamental position and force control performances of a small-sized pneumatic servo comprising a miniature cylinder and PWM driven control valves. The small-sized pneumatic servo has some advantages of increasing the powerjweight ratio, the stiffness and the response speed of the control system. In this paper, the effect of small-sizing is analyzed. Also, it is shown that the PWM carrier wave components can well work as a dither to decrease the influence of frictions. The unexpectedly satisfactory control performances can be obtained in the experiments.

关键词： Servomechanisms Pneumatic systems Minimization Position control Force control pulse-width modulation Dither

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PWM ASIC design for the three-phase bi-directional buck converter

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INTERNATIONAL JOURNAL OF ELECTRONICS 1996年第5期81卷 603-615页

作者： Rahim, NA Green, TC Williams, BW UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED DEPT ELECT ENGNLONDON SW7 2BTENGLAND HERIOT WATT UNIV DEPT ELECT & COMP ENGNEDINBURGH EH14 4ASMIDLOTHIANSCOTLAND

The design of hardware and software generation of the synchronous pulse-width modulation (PWM) suitable for the three-phase bi-directional AC-DC power converter is presented. The switching of the power devices is modulated by synchronous PWM implemented in an XC-3042 field programmable gate array (FPGA). There are no mains capture and synchronization problems. The utilization of the switches is based on the voltage-space vector control of an inverter. Displacement factor control is achieved in the design by decrement and increment of the phase-shift counter to give leading or lagging phase angle respectively. Results are provided to demonstrate the effectiveness of the design.

关键词： pulse-width modulation CONVERTERS (Electronics) ELECTRIC currents

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Effect of transition noise on the signal-to-noise ratio of magnetooptic read channels

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IEEE TRANSACTIONS ON MAGNETICS 1996年第4期32卷 3291-3304页

作者： Ozgunes, I Kumar, BVKV Kryder, MH CARNEGIE MELLON UNIV DEPT ELECT & COMP ENGN CTR DATA STORAGE SYST PITTSBURGH PA 15213 USA

The effect of transition noise on the soft bit error rate (BER) and the signal-to-noise ratio (SNR) in magnetooptic (MO) recording systems is studied, With high-density MO recording, transition noise and intersymbol interference (ISI) become problems, To study the effect of transition noise on the BER, we model the MO channel in the presence of transition noise, We develop separate models for the peak-position modulation (PPM) and pulse-width modulation (PWM) in order to understand the differences in the performances of the two different writing formats. We also describe how run-length-limited (RLL) coding can be incorporated into the models, Using the models developed, we study the effect of transition noise on the BER and the SNR for the decision feedback equalizer (DFE) method and the adaptive threshold detection scheme, Our study indicates that the DFE yields better SNR than the adaptive threshold detector, Also, the BER of PWM is better than the BER of PPM for the same user density, This implies that higher user densities can be achieved with PWM than with PPM for the same quality disk.

关键词： adaptive threshold detection scheme Bit error rate decision feedback equalisers decision feedback equalizer Decision feedback equalizers Detectors Intersymbol interference magnetic recording noise magneto-optical recording Magnetooptic effects magnetooptic read channels Magnetooptic recording magnetooptic recording systems peak-position modulation pulse position modulation pulse width modulation pulse-width modulation run-length-limited coding runlength codes Signal to noise ratio signal-to-noise ratio soft bit error rate Space vector pulse width modulation transition noise user density Writing writing formats

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pulse width modulated control of chaotic systems

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IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES 1996年第3期E79A卷 381-385页

作者： Konishi, K Otani, M Kokame, H Department of Electrical and Electronic Systems College of Engineering University of Osaka Prefecture Sakai-shi 593 Japan Faculty of Engineering Toyohashi University of Technology Toyohashi-shi 441 Japan

This letter proposes a pulse width modulated (PWM) control method which can stabilize chaotic orbits onto unstable fixed points and unstable periodic orbits. Some numerical experiments using the Lorenz equation show that chaotic orbits can be stabilized by the PWM control method. Furthermore, we investigate the stability in the neighborhood of an unstable fixed point and discuss the stability condition of the PWM control method.

关键词： controlling chaos pulse-width modulation unstable fixed point unstable periodic orbits

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SIMPLIFIED CONTROL STRATEGY TO IMPROVE AC-INPUT-CURRENT WAVE-FORM OF PARALLEL-CONNECTED CURRENT-TYPE PWM RECTIFIERS

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IEE PROCEEDINGS-ELECTRIC POWER APPLICATIONS 1995年第4期142卷 246-254页

作者： SATO, Y KATAOKA, T Dept. of Electr. & Electron. Eng. Tokyo Inst. of Technol. Japan

A new control method for parallel-connected current-type PWM rectifiers for high-power applications is proposed. To reduce waveform distortion and transient oscillation of the AC supply current, state-feedback control of the AC-side LC filter is introduced. A new method of generating a PWM pattern suitable for the parallel connected rectifiers is proposed to obtain sufficient controllability with a reduced switching frequency of the power devices. A method of balancing DC output currents of the component bridges is shown, and an analysis of the interbridge current is made. The effectiveness of the proposed control strategy is confirmed by experimental investigation employing a test system.

关键词： RECTIFIERS pulse-width modulation PARALLEL-CONNECTED RECTIFIERS WAVE-FORM DISTORTION

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ANALYSIS AND SIMULATION OF THE HIGH-SPEED TORQUE PERFORMANCE OF BRUSHLESS DC MOTOR-DRIVES

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IEE PROCEEDINGS-ELECTRIC POWER APPLICATIONS 1995年第3期142卷 191-200页

作者： SAFI, SK ACARNLEY, PP JACK, AG Dept. of Electr. & Electron. Eng. Newcastle upon Tyne Univ. UK

A simulation model for the performance prediction of brushless DC drives is used to investigate the high-speed torque performance for a motor switched by a PWM inverter. The solution is given for both 120 degrees and 180 degrees conduction angles of inverter operation, with provision for selecting the advance commutation angle. The influence of the more important drive parameters on high-speed performance is described. The paper also presents two simplified analytical approaches for obtaining the optimum phase-advance angle in the high-speed ranges. The merit of these methods, compared with trial-and-error based on simulation, is described.

关键词： DIRECT-CURRENT DRIVES INVERTERS MOTORS PREDICTION pulse-width modulation

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ELECTRIC RAILWAY TRACTION .2. TRACTION DRIVES WITH 3-PHASE INDUCTION-MOTORS

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POWER ENGINEERING JOURNAL 1994年第3期8卷 143-152页

作者： HILL, RJ Sch. of Electron. & Electr. Eng. Bath Univ. UK

The first in this series of tutorial articles described the nature of the traction load, the requirements of the traction duty cycle and power electronic controlled drives with DC traction motors (February 1994). This... 详细信息

关键词： motor control scheme electric drives PWM Power convertors and power supplies to apparatus direct self-control induction motors pulse-width modulation Drives dynamic performance traction Control of electric power systems railways electric railway traction VSI-fed drives Transportation invertors pulse width modulation pulse converter current source inverter three-phase induction motors voltage source inverter CSI VSI power convertors vector control machine control Asynchronous machines

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