Study Of A High-power Bi-directional DC/DC Converter Based On Soft-switching

With the development of science and technology, bidirectional DC/DC converters are increasingly used in applications such as DC uninterruptible power supplies, aerospace power systems, hybrid-energy electric vehicle, DC power amplifier and battery energy storage system.Employing soft-switching techniques in bidirectional DC/DC converters reduces switching loss and improves efficiency of the converters. The soft-switching converters can operate in higher frequency. As a result, the converters will have high power density and fast dynamic response.In this dissertation, a novel bidirectional DC/DC converter's topology was designed, witch used in vehicle power supply systems. The converter is composed of fundamental bidirectional switch cell, using phase-shifted full-bridge ZVS PWM DC/DC converter in buck circuit and using push-pull boost converter in boost circuit. The whole high power switch supply have four bidirectional DC/DC converters which are parallel connection.The theory of phase-shifted full-bridge ZVS PWM DC/DC converter and the theory of push-pull boost converter are introduced. The methods of realize ZVS(Zero Voltage Switching) is studied in detail. The control circuit and protected circuit is also designed in this dissertation. First Pspice simulation was used, witch proved the feasibility of the project. Then prototype aeroplane was excogitated to validate the result. Finally, the experimental waves of the prototype are given.