Abstract：Among the junction temperature monitoring methods of insulated gate bipolar transistor（IGBT），

the temperature-sensitive parameter method has attracted wide attention because of its fast response speed，low cost and easy on-line detection. Previous studies have shown that the gate threshold voltage（VTH）among the temperaturesensitive parameters has good temperature properties，but it is easily affected by current oscillation by direct measurement.Therefore，an indirect calculation method of threshold voltage based on Miller platform under resistive load was proposed. Firstly，the switching transient process of IGBT under resistive load was described，and the theoretical basis of VTH indirect calculation method was discussed. Then，the VTH was calculated indirectly by the voltage value of Miller platform in the switching process. Finally，the effectiveness of the method was proved by

experiments.

      Key words：insulated gate bipolar transistor（IGBT）；junction temperature；temperature-sensitive parameters；Miller platform；threshold voltage