Evaluation of thermo-sensitive electrical parameters based on the forward voltage for on-line chip temperature measurements of IGBT devices

The temperature of power semiconductor devices is one of the main issues affecting the performance, availability and reliability of power converters. The chip temperature is generally measured using Thermo-Sensitive Electrical Parameters (TSEPs). These parameters are relatively well controlled for laboratory temperature measurements where the power devices are not used under functional conditions. However, the use of TSEPs for chip temperature measurements in on-line conditions has yet to be demonstrated. This paper presents an experimental evaluation of two new TSEPs based on measuring the forward voltage, which could be used during operation of the converter. It examines the accuracy of the chip temperature measurement and also discusses the results in terms of robustness to the aging of power devices.