Instantaneous temperature estimation during short time overload operation of an IGBT

Abstract

In certain applications, such as motor soft starters, power electronic devices are required to operate only for brief durations. In low-cost product designs, the smallest component sizes are selected and temporarily overloaded during short intervals to minimize component costs and sizes. This paper delves into the current overload performance of an IGBT over a 2-second period. While the temperature of the die rises rapidly, the case temperature increase is delayed due to its thermal impedance, avoiding the possibility of a direct die temperature measurement from the case. This study utilizes the emitter PN junction of the IGBT for detecting the die temperature. The paper will provide a summary of the laboratory setup and experimental results to validate the testing methodology.