An Online Calibration Method for TSEP-based Junction Temperature Estimation for EV Traction Inverters

This paper proposes an online calibration method for the junction temperature estimation of power semiconductor devices in Electric Vehicle (EV) traction applications utilizing thermo-sensitive electrical parameters (TSEPs). It is achieved through the DC-link discharging operation mode of the traction inverter after the vehicle is parked, which is a natural and frequent activity in EV applications. Compared to conventional calibration schemes, the proposed method can be conveniently accomplished in a short term without the need for long-term data recording or complex operating states. The on-state saturation voltage of power semiconductors is used as a typical TSEP in this paper for the case study, and the proof-of-concept experiments based on a scaled-down inverter prototype verify the effectiveness, accuracy, and convenience of the proposed method.