Motor control method

A method for controlling a motor comprising a rotor having disposed thereon a permanent magnet and utilizing a magnet torque and a reluctance torque,

• wherein the permanent magnet is a composite permanent magnet having a magnetic phase and a grain boundary phase present around the magnetic phase, the magnetic phase has a core part and a shell part present around the core part, the Curie temperature of one of the core part and the shell part is Tc1 K, the Curie temperature of another is Tc2 K, and Tc2 K is higher than Tc1 K, and
• wherein when the magnitude of the reluctance torque is equal to or greater than the magnitude of the magnet torque, the temperature of the composite permanent magnet is set at Ts K that is (Tc1−100) K or higher and lower than Tc2 K and when the magnitude of the reluctance torque is less than the magnitude of the magnetic torque, the temperature of the composite permanent magnet is set at lower than the temperature Ts K or Tc1 K, whichever is lower.