CONTROL DEVICE OF PERMANENT MAGNET SYNCHRONOUS MOTOR FOR PREVENTING IRREVERSIBLE DEMAGNETIZATION OF PERMANENT MAGNET AND CONTROL SYSTEM INCLUDING THE SAME

摘要

A maximum current value determination unit determines the maximum current value of a permanent magnet synchronous motor in order to prevent irreversible demagnetization of a permanent magnet of the permanent magnet synchronous motor that may occur by transient current occurring at the time of short-circuiting of three phases, based on one of a set of irreversible demagnetization causing current value corresponding to permanent magnet temperature and the transient current occurring at the time of the short-circuiting of three phases, and a set of irreversible demagnetization causing magnetic field intensity corresponding to the permanent magnet temperature and demagnetization field intensity of the permanent magnet of the permanent magnet synchronous motor occurring at the time of the short-circuiting of three phases. A current control unit controls the current of the permanent magnet synchronous motor so that the current value of the permanent magnet synchronous motor is less than the maximum current value.