Junction temperature estimation method and device of power device

The invention discloses a junction temperature estimation method and device for a power device, and the method comprises the steps: determining a first junction temperature based on the shell temperature of a to-be-tested power device under a target test condition; correcting the first junction temperature based on a measurement error of the thermocouple to obtain a second junction temperature; determining a junction temperature difference value based on the difference between the third junction temperature and the first calibration junction temperature; and correcting the second junction temperature based on the junction temperature difference value to obtain a junction temperature estimation result of the to-be-tested power device under the target test condition. According to the method, a first junction temperature of a to-be-measured power device is obtained by using a thermocouple measurement method, the first junction temperature is corrected in combination with a thermocouple measurement error obtained