MOTOR CONTROL DEVICE

PROBLEM TO BE SOLVED: To provide a motor control device capable of satisfactorily determining the step-out of an AC motor based on a drive current of the AC motor. SOLUTION: The motor control device includes a basic wave frequency calculating section 10 for calculating the frequency of a basic wave component of a drive current to be supplied to the AC motor 12 from an inverter circuit 5 interposed between the AC motor 12 and a DC power supply to convert an output of the DC power supply into a three-phase AC based on the number of rotations of the AC motor 12, a band-pass filter 7 having a set frequency band for filtering according to the frequency of the basic wave component and filtering the drive current, an integrating section 8 for sectionally integrating the drive current after passing through the band-pass filter 7 over a predetermined period, and a decision unit 9 for determining whether the AC motor 12 is in a step-out state based on results of integration. COPYRIGHT: (C)2010,JPO&INPIT