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Guichao Hua

Bio: Guichao Hua is an academic researcher from Virginia Tech. The author has contributed to research in topics: Converters & Insulated-gate bipolar transistor. The author has an hindex of 13, co-authored 15 publications receiving 2555 citations.

Papers
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Journal ArticleDOI
29 Jun 1992
TL;DR: In this paper, a class of zero voltage transition (ZVT) power converters is proposed in which both the transistor and the rectifier operate with zero voltage switching and are subjected to minimum voltage and current stresses.
Abstract: A class of zero voltage transition (ZVT) power converters is proposed in which both the transistor and the rectifier operate with zero voltage switching and are subjected to minimum voltage and current stresses. The boost ZVT-PWM converter is used as an example to illustrate the operation of these converters. A 300 kHz, 600 W ZVT-PWM boost, DC-DC converter, and a 100 kHz, 600 W power factor correction circuit using the ZVT-PWM technique and an insulated gate bipolar transistor (IGBT) device were breadboarded to show the operation of the proposed converters. It is shown that the circuit technology greatly improves the converter performance in terms of efficiency, switching noise, and circuit reliability. >

896 citations

Journal ArticleDOI
20 Jun 1993
TL;DR: In this article, a new family of zero-current transition (ZCT) pulsewidth-modulated (PWM) converters is proposed for high power applications where the minority-carrier semiconductor devices (such as IGBTs, BJTs, and MCTs) are predominantly used as the power switches.
Abstract: A new family of zero-current-transition (ZCT) pulse-width-modulated (PWM) converters are proposed. The new family of converters implements zero-current turn-off for power transistor(s) without increasing voltage/current stresses and operates at a fixed frequency. The proposed converters are deemed most suitable for high-power applications where the minority-carrier semiconductor devices (such as IGBTs, BJTs, and MCTs) are predominantly used as the power switches. Theoretical analysis is verified on a 100-kHz, 1-kW ZCT-PWM boost converter using an IGBT. >

384 citations

Journal ArticleDOI
20 Jun 1994
TL;DR: In this paper, a zero-voltage and zero-current-switching (ZVZCS) full-bridge (FB) PWM converter is proposed to overcome the limitations of the ZVS-FB-PWM converter such as high circulating energy, loss of duty cycle, and limited ZVS load range for the lagging-leg switches.
Abstract: A novel zero-voltage and zero-current-switching (ZVZCS) full-bridge (FB) pulse-width modulated (PWM) converter is proposed. The new converter overcomes the limitations of the zero-voltage-switching (ZVS)-FB-PWM converter, such as high circulating energy, loss of duty cycle, and limited ZVS load range for the lagging-leg switches. By using the DC blocking capacitor and adding a saturable inductor, the primary current during the freewheeling period is reduced to zero, allowing the lagging-leg switches to be operated with zero-current-switching (ZCS). Meanwhile, the leading-leg switches are still operated with ZVS. The new converter is attractive for high-voltage (400-800 V), high-power (2-10 kW) applications where IGBTs are predominantly used as the power switches. The principle of operation, features, and design considerations of the new converter are described and verified on a 2-kW, 100-kHz, IGBT-based experimental circuit.

307 citations

Journal ArticleDOI
TL;DR: Three classes of zero-voltage soft-switching PWM converters and their merits and limitations are assessed, and experimental results of several prototype of converters are presented to illustrate each class.
Abstract: A number of soft-switching pulse-width-modulated (PWM) converter techniques have been proposed, aimed at combining the desirable features of both the conventional PWM and resonant converters while avoiding their respective limitations. In this paper, three classes of zero-voltage soft-switching (PWM) converters (namely the zero-voltage-switched (ZVS) quasi-square-wave converters, ZVS-PWM converters, and zero-voltage-transition PWM converters) and two classes of zero-current soft-switching PWM converters (namely, the zero-current-switched PWM converters and zero-current-transition PWM converters) are reviewed, and their merits and limitations are assessed. Experimental results of several prototype of converters are presented to illustrate each class of converter.

302 citations

Proceedings ArticleDOI
07 Mar 1993
TL;DR: In this paper, a single-phase power factor correction scheme is proposed based on the power flow analysis, where the PFC circuit is in parallel with the major power flow path, thus reducing its size and weight compared to a conventional two-cascade stage scheme.
Abstract: A single-phase power factor correction scheme is proposed based on the power flow analysis. It is found that the conventional power factor correction (PFC) circuit must be designed to handle the rated power, although its purpose is only for power factor correction. With the proposed scheme, the PFC circuit is in parallel with the major power flow path, thus reducing its size and weight compared to a conventional two-cascade-stage scheme. A prototype circuit is built and tested to verify this concept. >

196 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, the authors present the current status and implementation of battery chargers, charging power levels, and infrastructure for plug-in electric vehicles and hybrid vehicles and classify them into off-board and on-board types with unidirectional or bidirectional power flow.
Abstract: This paper reviews the current status and implementation of battery chargers, charging power levels, and infrastructure for plug-in electric vehicles and hybrids. Charger systems are categorized into off-board and on-board types with unidirectional or bidirectional power flow. Unidirectional charging limits hardware requirements and simplifies interconnection issues. Bidirectional charging supports battery energy injection back to the grid. Typical on-board chargers restrict power because of weight, space, and cost constraints. They can be integrated with the electric drive to avoid these problems. The availability of charging infrastructure reduces on-board energy storage requirements and costs. On-board charger systems can be conductive or inductive. An off-board charger can be designed for high charging rates and is less constrained by size and weight. Level 1 (convenience), Level 2 (primary), and Level 3 (fast) power levels are discussed. Future aspects such as roadbed charging are presented. Various power level chargers and infrastructure configurations are presented, compared, and evaluated based on amount of power, charging time and location, cost, equipment, and other factors.

2,327 citations

Journal ArticleDOI
TL;DR: This paper presents an exhaustive review of three-phase improved power quality AC-DC converters configurations, control strategies, selection of components, comparative factors, recent trends, their suitability, and selection for specific applications.
Abstract: Solid-state switch-mode rectification converters have reached a matured level for improving power quality in terms of power-factor correction (PFC), reduced total harmonic distortion at input AC mains and precisely regulated DC output in buck, boost, buck-boost and multilevel modes with unidirectional and bidirectional power flow. This paper deals with a comprehensive review of improved power quality converters (IPQCs) configurations, control approaches, design features, selection of components, other related considerations, and their suitability and selection for specific applications. It is targeted to provide a wide spectrum on the status of IPQC technology to researchers, designers and application engineers working on switched-mode AC-DC converters. A classified list of more than 450 research publications on the state of art of IPQC is also given for a quick reference.

1,691 citations

Journal ArticleDOI
TL;DR: A review of the most interesting solutions for single phase and low power applications is carried out in this article, where the major advantages and disadvantages are highlighted and the field of application is found.
Abstract: New recommendations and future standards have increased the interest in power factor correction circuits. There are multiple solutions in which line current is sinusoidal. In addition, a great number of circuits have been proposed with nonsinusoidal line current. In this paper, a review of the most interesting solutions for single phase and low power applications is carried out. They are classified attending to the line current waveform, energy processing, number of switches, control loops, etc. The major advantages and disadvantages are highlighted and the field of application is found.

652 citations

Patent
26 Jan 2006
TL;DR: In this article, a switching power-supply circuit consisting of rectifying and smoothing means for generating a rectified and smoothed voltage and outputting the rectified voltage as a direct-current input voltage was proposed.
Abstract: The present invention relates to a switching power-supply circuit comprising: rectifying and smoothing means for generating a rectified and smoothed voltage and outputting the rectified and smoothed voltage as a direct-current input voltage; an insulating converter transformer for transferring a primary-side output to a secondary side; switching means for intermittently passing on the direct-current input voltage to a primary winding of the insulating converter transformer; a primary-side resonance circuit for actuating the switching means in a voltage resonance mode; power-factor improvement means for improving a power factor by generating intermittently a rectified current based on the fed-back switching output voltage; a secondary-side resonance circuit on a secondary side of the insulating converter transformer; direct-current output voltage generation means carrying out a rectification operation in order to generate a secondary-side direct-current output voltage; and constant-voltage control means for executing constant-voltage control on the secondary-side direct-current output voltage.

526 citations

Proceedings ArticleDOI
20 Jun 1994
TL;DR: In this article, a new family of single stage isolated power factor correctors is proposed, which features fast regulation of the output voltage, one or two power switches operated in unison, a single control loop, and automatic shaping of the line current.
Abstract: A new family of single stage isolated power-factor correctors features fast regulation of the output voltage, one or two power switches operated in unison, a single control loop, and automatic shaping of the line current. We give topologies, steady-state analysis, design considerations, and experimental results. >

461 citations