Phase-Shift Full-Bridge (PSFB) Converter Integrated Double-Inductor Rectifier With Separated Resonant Circuits (SRCs) for 800-V High-Power Electric Vehicles

Abstract

The main battery voltage of electric vehicles (EVs) has been suggested to increase to an 800-V system, which improves driving distance and charging speed. However, the design of an 800-V dc/dc converter is challenging because of the high voltage and current stress of the switching devices. Therefore, this article proposes a novel double-inductor rectifier with separated resonant circuits (SRCs) based on a phase-shift full-bridge (PSFB) converter for 800-V on- board charger (OBC) applications, which overcomes the drawbacks of the frequency stress of the diodes in a single-series resonant circuit (SSRC). Moreover, the configuration of input-series–output-parallel (ISOP) improves the voltage safety margin, and the use of 650-V switching devices reduces the system cost. In addition, the SRC achieves more effective energy transfer, which greatly reduces the switching loss and the thermal effects of high-power transmission by achieving a wide range of zero-voltage switching (ZVS) in the leading-leg switches and zero-current switching (ZCS) in the lagging-leg switches. Finally, the effectiveness of the proposed converter is validated on a 760-V/20-kW experimental prototype with 98.3% maximum efficiency.