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IEEE International Symposium on Industrial Electronics (ISIE)

作者： Oliveira, K. C. Cavalcanti, M. C. Afonso, J. L. Farias, A. M. Neves, F. A. S. Univ Fed Pernambuco Dept Elect Engn Recife PE Brazil Univ Minho Dept Ind Elect Guimaraes Portugal

ISBN: (纸本)9781424463916

In some photovoltaic applications it is possible to remove the transformer of the system in order to reduce losses, cost and size. In transformerless systems the photovoltaic module parasitic capacitance can introduce leakage currents in which the amplitude depends on the converter topology, on the pulse-width-modulation and on the resonant circuit composed by the system components. In this paper a modulation technique for three-phase neutral point clamped multilevel inverters is proposed to eliminate the leakage current in photovoltaic systems without requiring any modification on the multilevel inverter. The neutral point clamped inverter is studied for systems with function of active filter using the p-q theory. The proposed system presents control of the maximum power point and compensation of current harmonics and reactive power.

关键词： active filter clamped multilevel inverters converter topology current harmonics invertors leakage currents maximum power point neutral point clamped p-q theory photovoltaic module parasitic capacitance photovoltaic power systems pulse width modulation pulse-width-modulation reactive power three-phase neutral point transformerless photovoltaic systems transformerless systems

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Analysis and Design of High Performance Voltage-Doubler Rectifier

Analysis and Design of High Performance Voltage-Doubler Rect...

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5th IEEE Conference on Industrial Electronics and Applications

作者： Wang, Chien-Ming Lin, Chang-Hua Yang, Teng-Chieh Lin, Hsin-Yi Natl Ilan Univ Dept Elect Engn Ilan Taiwan Tatung Univ Dept Elect Engn Taipei Taiwan

ISBN: (纸本)9781424450466

This paper analyses and designs a new soft-switching single-phase high power factor voltage-doubler rectifier. The proposed rectifier combines the conventional pulse-width-modulation technique, soft commutation technique and instantaneous average line current control to promote the circuit performance. Comparison with conventional boost rectifier, the proposed rectifier own double voltage function at output port without additional voltage stress on main switches. A soft-switching auxiliary circuit is configured in the presented rectifier to provide the soft-switching function on main switches and auxiliary switches and improve the problem of switching losses and EMI. The proposed converter uses dual boost converter type to reduce the semiconductor count on power flow path and reduce conduction losses. In the control strategy, the proposed circuit uses the average current control mode to synthesize a stable sine-wave input current with low harmonics. A prototype has been implemented in laboratory to verify circuit theory.

关键词： voltage-doubler rectifier pulse-width-modulation

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Reduction of Common Mode Currents generated by Three-Level Inverters with Consideration of Motor Overvoltages

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EPE JOURNAL 2009年第3期19卷 22-30页

作者： Videt, Arnaud Le Moigne, Philippe Idir, Nadir Baudesson, Philippe Franchaud, Jean-Jacques Ecrabey, Jacques Schneider Toshiba Inverter Europe F-27120 Pacy Sur Eure France Ecole Cent Lille L2EP F-59651 Villeneuve Dascq France USTL L2EP F-59655 Villeneuve Dascq France Schneider Elect F-38050 Grenoble 9 France

In adjustable speed drive applications, the switching of the inverter semiconductors generates common mode currents as well as harmful overvoltages on the motor terminals when long cables are used. Consequently, bulky and expensive input and output filters must be used. This work aims at reducing these disturbances from their origin by using a three-level neutral-point-clamped (NPC) inverter controlled with a new pulse-width-modulation (PWM) strategy. Whereas previous common mode noise-reducing strategies usually generate higher overvoltages than conventional ones, the proposed PWM is able to manage both problems thanks to its internal degrees of freedom.

关键词： Electromagnetic compatibility common mode current pulse-width-modulation neutral-point-clamped inverter overvoltage

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On The Driving Techniques for High-Brightness LEDs

On The Driving Techniques for High-Brightness LEDs

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IEEE Energy Conversion Congress and Exposition

作者： Loo, K. H. Lun, Wai-Keung Tan, Siew-Chong Lai, Y. M. Tse, Chi K. Hong Kong Polytech Univ Fac Engn Kowloon Hong Kong Peoples R China Hong Kong Polytech Univ Elect & Informat Engn Dept Kowloon Hong Kong Peoples R China

ISBN: (纸本)9781424428922

High-brightness light-emitting diodes (HBLEDs) are conventionally driven in the amplitude mode (AM) or pulse-width-modulation (PWM) mode. High luminous efficacy is obtained with AM, but precise dimming is difficult to achieve and such AM-driven LEDs suffer from significant color variations. PWM offers excellent dimming capability and color stability but the LEDs acquire lower luminous efficacies compared to AM. The advantageous features of both conventional methods can be united in a single generalized methodology as proposed in this paper. It utilizes pulsating current while enables simultaneous adjustments of the current levels and duty cycle for achieving a predetermined luminous efficacy and dimming range of interest to the users. The dimming dynamics using the proposed method is investigated through a detailed parametric study by experiments and numerical calculations.

关键词： Light-emitting diode pulse-width-modulation amplitude mode direct current lighting system high-brightness LEDs luminous efficacy bi-level driving

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LED brightness control for video display application

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DISPLAYS 2008年第5期29卷 506-511页

作者： Svilainis, L. Kaunas Univ Technol Signal Proc Dept LT-51368 Kaunas Lithuania

The technique is suggested for a kind of pulse-width-modulation LED dimming in LED video displays. The significant increase of the gray levels number and image refresh frequency can be achieved when the large number of LEDs is controlled serially. The need for a large number of grayscale levels and high refresh rate is explained. The controlling data flow and the amount of buffer memory are the same as with binary-weighted pulse-width-modulation. Spreading the switching pulses in time reduces the electromagnetic interference. (C) 2008 Elsevier B.V. All rights reserved.

关键词： LED dimming LED video display pulse-width-modulation LED display electronics

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Embedded EZ-Source Inverters

Embedded EZ-Source Inverters

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2008 IEEE Industry Applications Society Annual Meeting (IAS 2008), vol.3

作者： P. C. Loh F. Gao F. Blaabjerg School of Electrical and Electronic Engineering Nanyang Technological University Singapore Institute of Energy Technology University of Aalborg Denmark

Z-source inverters are recent topological options proposed for buck-boost energy conversion with a number of possible voltage and current-type circuitries already reported in the literature. Comparing them, a common feature noted is their inclusion of a LC impedance network, placed between the dc input source and inverter bridge. This impedance network allows the output end of a voltage-type Z-source inverter to be shorted for voltage-boosting without causing a large current flow, and the terminal current of a current-type inverter to be interrupted for current boosting without introducing over-voltage oscillations to the system. Therefore, Z-source inverters are in effect safer and less complex, and can be implemented using only passive elements with no additional active semiconductor needed. Believing in the prospects of Z-source inverters, this paper contributes by introducing a new family of embedded EZ-source inverters that can produce the same gain as the Z-source inverters, but with smoother and smaller current/voltage maintained across the dc input source and within the impedance network. These latter features are attained without using any additional passive filter, which surely is a favorable advantage since an added filter will raise the system cost, and at times can complicate the dynamic tuning and resonant consideration of the inverters. The same embedded concept can also be used for designing a full range of voltage and current-type inverters with each of them tested experimentally using a number of scaled down laboratory prototypes.

关键词： EZ-source inverters Z-source inverters Neutral-point-clamped inverters pulse-width-modulation

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An improved ZVS PWM three-level converter

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IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 2007年第1期54卷 319-329页

作者： Jin, Ke Ruan, Xinbo Liu, Fuxin Nanjing Univ Aeronaut & Astronaut Coll Automat Engn Aero Power Sci Tech Ctr Nanjing 210016 Peoples R China

This paper proposes an improved zero-voltage-switching pulse-width-modulation three-level converter (ZVS PWM TL converter), which is improved from the original ZVS PWM TL converter just by exchanging the position of the resonant inductor and the transformer, such that the transformer is connected with the lagging switches. The improved converter has several advantages over the original one, e.g., the clamping diodes conduct only once in a switching period, and the resonant inductor current is smaller in zero state, leading to a higher efficiency and reduced duty cycle loss. A blocking capacitor is usually introduced, p to the primary side to prevent the transformer from saturating, this paper analyzes the effects of the blocking capacitor in different positions, and a best scheme is determined. A 2.5-kW prototype converter verifies the effectiveness of the improved converter and the best scheme for the blocking capacitor.

关键词： clamping diode pulse-width-modulation three-level converter zero-voltage-switching

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New Space Vector Control Approach for Four Switch Three Phase Inverter (FSTPI)

New Space Vector Control Approach for Four Switch Three Phas...

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2007 International Conference on Power Electronics and Drive Systems (PEDS 2007), vol,3

作者： Phan Quoc Dzung Le Minh Phuong Pham Quang Vinh Nguyen Minh Hoang Tran Cong Binh Electrical & Electronic Engineering HCM City University of Technology Ho Chi Minh Vietnam Siemens AG Ho Chi Minh Vietnam NARC Ulsan University South Korea

This paper is to present a space vector PWM algorithm for four switch three phase inverters (B4, FSTPI) based on the one for six switch three phase inverters (B6, SSTPI) (principle of similarity) where the αβ plan is divided into 6 sectors and the formation of the required reference voltage space vector is done in the same way as for B6 by using effective (mean) vectors. This facilitates the calculation for B4 and some studies on B6 can be applied for B4 as well through this proposed similarity, e.g. the problem with PWM in the overmodulation zone due to the complicated non-linear character there. Matlab/Simulink is used for the simulation of the proposed SVPWM algorithm for undermodulation, overmodulation mode 1 and 2. This SVPWM approach is also validated experimentally using control board TMS eZDSP2812 (Texas Instrument Co.).

关键词： B4 (Four Switch Three Phase Inverter) B6 (Six Switch Three Phase Inverter) Low-cost inverter Overmodulation pulse-width-modulation Space vector Undermodulation

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The Development of Artificial Neural Network Space Vector PWM for Four-Switch Three-Phase Inverter

The Development of Artificial Neural Network Space Vector PW...

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2007 International Conference on Power Electronics and Drive Systems (PEDS 2007), vol,3

作者： Phan Quoc Dzung Le Minh Phuong Pham Quang Vinh Electrical & Electronic Engineering HCM City University of Technology Ho Chi Minh Vietnam Siemens AG Ho Chi Minh Vietnam

This paper presents the development of neural-network-based controller of space vector modulation (ANN-SVPWM) for low-cost voltage-source inverters. This ANN-SVPWM controller completely covers the undermodulation and overmodulation modes with operation extended linearly and smoothly up to square wave (six-step). The ANN controller has the advantage of the very fast implementation of an SVM algorithm that can increase the switching frequency of power switches of the static converter, this point has a very important sense for minimizing DC bus capacitance, unbalanced DC source and the ripple of load current The ANN controller uses the individual training strategy with the fixed weight and supervised models. A computer simulation program is developed using Matlab/Simulink together with the Neural Network Toolbox for training the ANN-controller.

关键词： Artificial Neural Network Four-Switch Three-Phase Inverter (FSTPI) Low-cost Inverter Overmodulation pulse-width-modulation Six-Switch Three-Phase Inverter (SSTPI) Space vector Undermodulation

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A New Switching Technique for Direct Torque Control of Induction Motor using Four-Switch Three-Phase Inverter

A New Switching Technique for Direct Torque Control of Induc...

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2007 International Conference on Power Electronics and Drive Systems (PEDS 2007), vol,4

作者： Phan Quoc Dzung Le Minh Phuong Pham Quang Vinh Nguyen Minh Hoang Nguyen Xuan Bac Electrical & Electronic Engineering HCM City University of Technology Ho Chi Minh Vietnam Siemens AG Ho Chi Minh Vietnam NARC Ulsan University South Korea

This paper presents a new switching technique for Direct Torque Control of Induction Motor using Four-Switch Three Phase Inverter (DTC-FSTPI-IM) for low power applications. The modified switching table in this method is based on the principle of similarity between FSTPI and SSTPI (Six-Switch Three Phase Inverter), where the αβ plan is divided into 6 sectors and the formation of the voltage space vector is done in the same way as for SSTPI by using effective (mean) vectors. This approach allows using the well-knowing established switching table of SSTPI for FSTPI, in order to reduce torque ripples in comparison with the conventional DTC method for FSTPI. The validity of new proposed technique is verified by simulation results using Matlab/Simulink and also experimentally by using DSpace 1104 Card.

关键词： Direct Torque Control Four-Switch Three-Phase Inverter (FSTPI) Optimal Switching Table pulse-width-modulation Six-Switch Three-Phase Inverter (SSTPI) Space Vector

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