Junction Temperature Extraction Approach With Turn Off Delay Time for High Voltage High Power IGBT Modules
Thermo sensitive electrical parameter (TSEP) approaches are widely employed in the junction temperature extraction and prediction of power semiconductor devices. In this paper, the turn off delay time is explored as an indicator of a TSEP to extract the junction temperature from high power insulated gate bipolar transistor (IGBT) modules. The parasitic inductor LeE between the Kelvin and power emitter terminals of an IGBT module is utilized to extract the turn off delay time. Furthermore, the monotonic dependence between the junction temperature and turn off delay time is investigated. The beginning and end point of the turn off delay time can be determined by monitoring the induced voltage veE across the inductor LeE. A dynamic switching characteristic test platform for high power IGBT modules is used to experimentally verify the theoretical analysis. The experimental results show that the dependency between IGBT junction temperature and turn off delay time is near linear. It is established that the turn off delay time is a viable TSEP with good linearity, fixed sensitivity, and offers nondestruction on line IGBT junction temperature extraction.
IEEE Transactions on Power Electronics