Control device for detecting whether or not irreversible demagnetization of permanent magnet of permanent magnet synchronous motor has occurred

摘要

An estimated torque constant calculation unit calculates an estimated torque constant relating to the permanent magnet synchronous motor from a current representative value and an acceleration representative value acquired from a plurality of current values and a plurality of acceleration values in the same operation state over a plurality of periods of a sinusoidal command signal and a predetermined inertia relating to the permanent magnet synchronous motor. A demagnetization detection 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 relating to the permanent magnet synchronous motor.