| 摘要 |
PROBLEM TO BE SOLVED: To properly detect a failure of an inverter while preventing damage of a booster due to an overcurrent.SOLUTION: If an overcurrent of a booster 7 occurs, all switching elements 13 in an inverter 5 are temporarily controlled to be an off state in a forced stop period. Failure determination means 51b determines failure occurrence by: measuring a cumulative time period during which an amount of a current deviation between a detected current value and a target value for a motor 2 is maintained at or above the amount of the threshold value for determination, before and after occurrence of an overcurrent state except a forced stop period, in the case that the overcurrent state occurs while measuring a time period in which the amount of the current deviation between the detected current value and the target value for the motor 2 is maintained at or above the amount of the threshold value for determination; and by determining that the measured cumulative time period is at or above a reference time. |
