Li-Wei Lin

A bidirectional DC–DC converter for fuel cell electric vehicle driving system

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. The simulation and experimental waveforms for the proposed converter are shown to verify its feasibility.

A multiple-input DC/DC converter for renewable energy systems

This paper presents a multiple-input DC/DC converter for renewable energy systems. The proposed DC/DC converter can be used to obtain well-regulated output voltage from several power sources, such as wind turbines, photovoltaic arrays, fuel cells, etc. The energy provided by these power sources can be simultaneously transferred into the load. The proposed multiple-input DC/DC converter has the advantages of simple configuration, fewer components, lower cost and high efficiency. The operating principle, theoretical analysis, and design criteria are provided in this paper. A laboratory prototype with two different power sources was successfully implemented and tested. The simulation and experimental results are given to verify the feasibility of the proposed scheme

A high-efficiency soft-switched AC/DC converter with current-doubler synchronous rectification

An improved ac/dc converter based on asymmetrical half-bridge topology is proposed in this paper. To substantially enhance the efficiency for low-voltage/high-current output applications, a current-doubler synchronous rectifier is combined with a modified asymmetrical half-bridge converter that retains the inherent zero-voltage-switching property. The power losses in the secondary rectification stage and the primary switches can be significantly reduced. The proposed architecture exhibits extreme simplicity and lower cost while providing unity power factor, well-regulated output, and high power density. The detailed operating principles and design procedures for the proposed converter are described in this paper. Simulation and experimental results for a laboratory prototype are discussed to verify the feasibility.

Current Imbalance Elimination for a Three-Phase Three-Switch PFC Converter

In this letter, a current-sharing method is studied for eliminating current imbalance problem among three single-phase modules in a three-phase three-switch power factor correction converter. The operating principles and design considerations are analyzed and discussed. A 750W laboratory prototype is implemented and tested to verify the feasibility of the proposed method.

A single-stage dimmable electronic ballast with high power factor

A novel fixed frequency electronic ballast that consists of a single-stage asymmetrical half-bridge inverter, a load resonant tank and a switched-capacitor dimming control circuit is proposed for driving fluorescent lamps. High efficiency and unity power factor are achieved by the proposed single-stage topology. The switched-capacitor dimming control technique in the studied high frequency electronic ballast provides better EMI features. The steady-state operating principle and design procedure for the proposed single-stage dimmable electronic ballast are analyzed and discussed in detail. A ballast prototype was implemented at the laboratory. The experimental results verify the feasibility of the proposed method.

Dual Mode Control Multiphase DC/DC Converter for CPU Power

High performance voltage-regulator-modules (VRMs) for the new generation of microprocessors have many strict and challenging specifications that include high power-density, high output-current capability, low output-voltage deviation and fast transient-response. In this paper, a dual mode control multiphase DC/DC converter is presented. The proposed scheme combines voltage and hysteretic control modes and has the merits of high efficiency, simple control and fast transient response. It can be also used for single-phase and built in integrated circuit without additional cost and space. The operating principles and design considerations are analyzed and discussed in detail. A 1.3 V/80 A four-phase laboratory prototype was simulated and implemented to verify the feasibility of the proposed scheme. The results are satisfactory

PAS power supply harmonic elimination by active conditioner

An active power line conditioner is proposed for an aerospace power system that is composed of multiple paralleled power modules. The current harmonics generated by the power supply system can be eliminated and the number of modules in the power supply system can be reduced. Experimental results on a prototype system were shown to verify the feasibility of this method. The proposed power supply system demonstrates benefits such as high efficiency, low current harmonics, and simple configuration.