Patent ID: 9692342
Date: 2017-06-27
CPC Classifications: B62D,H02K,H02P

Claim:
1. A motor control device that controls energization of a brushless motor for an electric power steering device that assists a steering operation, the brushless motor comprising a stator having a plurality of winding sets for a plurality of systems respectively, and a rotator having a ferrite magnet, the motor control device comprising: a plurality of inverters for the systems respectively, each of which corresponds to a winding set of a respective system, and supplies an alternating current to the winding set of the respective system; a current command value calculation device that calculates a dq-axis current command value for energizing the winding sets; a temperature estimation device that estimates temperature of the ferrite magnet; and a temperature rising control device that calculates a temperature rising dq-axis current command value, to be added to the dq-axis current command value, for flowing a temperature rising current in the winding sets when an estimated temperature is lower than a predetermined value; a maximum current limit device that controls the dq-axis current command value, wherein: the maximum current limit device decreases a maximum current limit value of the dq-axis current command value when the temperature estimated by the temperature estimation device is reduced.