Efficient, High-Temperature Bidirectional Dc/Dc Converter for Plug-in-Hybrid Electric Vehicle (PHEV) using SiC Devices

A multiphase all-SiC dc/dc bidirectional converter for plug-in-hybrid electric vehicles (PHEV) is described in this paper that serves as a regulated charger for the intermediate high-voltage energy storage device (e.g. ultracapacitor) in the motoring mode and allows recharging of the batteries during regenerative mode. The primary focus of this paper is to describe the design of the converter and experimentally evaluate its performance (steady-state efficiency and load-sharing and dynamic performance) at high coolant temperatures (ges 105degC). Further, the key components of the converter losses at high temperature are identified. Because VJFET switching losses are the key component of the converter loss, the effectiveness of a soft-switching scheme that mitigates these losses is also evaluated.