Control device that detects whether or not an irreversible demagnetization occurred in a permanent magnet of a permanent magnet synchronous motor

摘要

An estimated torque constant calculating unit calculates an estimated torque constant with respect to the permanent magnet synchronous motor from a representative current value and a representative acceleration value obtained from a plurality of current values and a plurality of acceleration values in the same operating state over a plurality of periods of a sine command signal and a predetermined inertia on the permanent magnet synchronous motor. A demagnetization detecting unit detects whether or not irreversible demagnetization has occurred in the permanent magnet of the permanent magnet synchronous motor based on a difference between the estimated torque constant and a predetermined torque constant with respect to the permanent magnet synchronous motor.