A high temperature traction inverter with reduced cooling and improved efficiency for HEV applications

This paper presents a 30 kW Si IGBT based three-phase traction inverter for operating at the junction temperature of 200°C with the reduced cooling and improved efficiency in hybrid electric vehicle (HEV) applications. The high temperature capable Si devices based module is developed for operation with the 105°C high temperature engine coolant, leading to lower cost and higher power density. A variable switching frequency pulse width modulation (VSFPWM) scheme is employed to relieve the negative effect of high temperature on loss. The experimental results demonstrate that the three-phase converter can operate continuously with the 105°C high temperature coolant. The efficiency is increased from 94.98 % to 95.73 % after VSFPWM is applied at full load.