The Research Of Small Power Capacity Phase Shifted Full Bridge ZVS Converter

The improvement and evolution of vehicle power supply system has experienced fourprocesses: low-voltage DC power、constant speed constant frequency AC power、variablespeed constant frequency AC power and high-voltage DC power. Finally, High-voltage DCpower obtains the universal concern of experts and scholars in and abroad for its highpower density、high efficiency、high work reliability.Switch mode power supply(SMPS) is one of the research focus in power electronic,Among the SMPS, Full-bridge converter with soft switch technology, can be made of high-voltage、high-power、high-efficiency DC power. This paper took phase shifted full bridgesoft switch converter (PSFB-ZVS) with clamping diodes for the research object, Only bythe use of the leakage inductance of the high-frequency transformer and the internalcapacitors of the switches, Phase Shifted Full Bridge ZVS Converter achieve ZVS, amongthe leading leg realizes the full load range ZVS, while the lagging leg realizes ZVS in acertain range, this soft switch converter effectively reduces the switch losses and enable theimprovement of switch frequency, then the volume and weight of the converter reducedgreatly. The converter with two clamping diodes can effectively restrain the voltageoscillation and peak of rectified output voltage in secondary side. PSFB-ZVS have beenwidely used in medium-high power stage, e.g., High-Voltage DC (HVDC) aeronauticalpower system, Welding power supply, Electrical operation power supply and so on.Firstly, the paper simply introduces the operation principle of PSFB-ZVS with theclamping diodes in primary of the high-frequency transformer; Then some key simulationwaveforms are presented with the help of the simulation software Saber, it further verifiesthe rationality of the designed parameters; Finally, double close loop controller of PSFB-ZVS is obtained with the help of MATLAB tool based on the small signal model of theconverter.