Motor drive apparatus and electric power steering apparatus using the same

摘要

A motor drive apparatus has a plurality of motor drive parts and a control unit. The control unit performs first and second failure detection processing for the motor drive parts before starting to drive the motor. If the first motor drive part is determined to have failure by the first failure detection processing, a first power supply relay for the first motor drive part is turned off and the second failure detection processing for the first motor drive part is inhibited. If the second motor drive part is determined to have no failure by the first failure detection processing and then by the second failure detection processing, the motor is started to operate.