Estimation of Both Junction Temperature and Load Current of IGBTs from Output Voltage of Gate Driver

抄録

For the online condition monitoring of IGBTs, a new estimation method of both the junction temperature (T_J) and the load current (I_L) of IGBTs using a momentary high-Z gate driving (MHZGD) from the output voltage (V_OUT) of the gate driver is proposed, which can be integrated into the gate driver ICs. T_J is estimated from V_OUT difference during and after the MHZGD period, and I_L is estimated from V_OUT during MHZGD. In the 110 switching measurements at 11 different T_J's from 25 °C to 125 °C and 10 different I_L's from 12.5 A to 80 A for each of the three IGBTs, T_J and I_L estimation errors in a low test cost parameter determination method are + 4.9 °C / − 8.4 °C and + 1.1 A / − 4.3 A, respectively. In contrast, T_J and I_L estimation errors in a parameter determination method with small error are + 4.9 °C / − 8.1 °C and + 1.0 A / − 1.8 A, respectively.