Elimination of bus voltage impact on temperature sensitive electrical parameter during turn-on transition for junction temperature estimation of high-power IGBT modules

Junction temperature is of great importance to safe operating area of IGBT modules. Various information of the IGBT operating state is reflected on electrical characteristics during turn-on transient. A unified extraction method for internal junction temperature via dynamic thermo-sensitive electrical parameters (DTSEP) during turn-on transient is proposed. Two DTSEP, turn-on delay time (tdon) and the maximum increasing rate of collector current dic/dt(max), are combined to eliminate the bus voltage impact. Using the inherent emitter-auxiliary inductor LeE in high-power modules, the temperature-dependent DTSEPs can be converted into a low-voltage and measurable signal. Finally, experiment results are exhibited to verify the effectiveness of proposed method.