| abstract |
(57) [Summary] [PROBLEMS] To predict failure of a power semiconductor element due to thermal stress. SOLUTION: In a temperature change generated based on a current change by current control of a power semiconductor element, utilizing a predetermined relationship between a temperature difference of the temperature change and the number of operable cycles of the power semiconductor element, Predict failure of a power semiconductor device due to thermal stress. In a power semiconductor element that performs current control, the temperature change of the power semiconductor element due to the current change is considered as one cycle, the temperature information of the power semiconductor element is obtained, and the operable cycle for the temperature difference in the operation of keeping the temperature difference of the temperature change constant The number of operable cycles of the power semiconductor element is determined from the temperature difference corresponding to the determined temperature information based on the number relationship, and a failure of the power semiconductor element is estimated based on the determined number of operable cycles. |