Patent ID: 8723469
Filing Date: 2014-05-13
Classification: H02P

Abstract:
1. A motor winding overheat prevention apparatus comprising: a stator winding temperature calculation unit which calculates stator winding temperature based on the ambient temperature of a motor and on the amount of change in the temperature of a stator winding that is estimated from current flowing in said stator winding of said motor; a position sensor temperature detection unit which detects the temperature indicated by a temperature sensing element incorporated in a position sensor that detects positional information of a rotor of said motor; and an alarm signal output unit which outputs an alarm signal when said stator winding temperature exceeds an alarm level, wherein when said ambient temperature is not higher than a prescribed temperature, said alarm level is set equal to a temperature preset based on said ambient temperature and a maximum value of the amount of said temperature change, while when said ambient temperature is higher than said prescribed temperature, said alarm level is set equal to a temperature preset in order to protect said position sensor from overheating.