| 摘要 |
PROBLEM TO BE SOLVED: To protect a power semiconductor device of a motor and a motor driving part by preventing overheating of the motor and the motor driving part. SOLUTION: A motor ambient temperature sensor 26 is arranged in the vicinity of an electric motor 10. A motor driving part ambient temperature sensor 27 is arranged in the vicinity of a motor driving circuit 45. Motor heating value 54a and a motor driving part heating value 55a are estimated based on motor cirrent IM. A motor heating value regulating part 52 presumes temperature rise of the electric motor 10 based on a motor ambient temperature TM and the motor heating valve 54a. When it is overheated, a current limit value 52a is output. A motor driving part heating value regulating part 53 presumes temperature rise of the motor driving circuit 45 based on motor driving part ambient temperature TD and the motor riving part heating value 55a. When it is overheated, a current limit value 53a is output. A current regulating part 51 is so operated that a motor driving control signal ITH supplied to a motor driving part 40 is not more than the current limit values 52a, 53a. |
