Permanent magnet electric motor with heating device and operating method

摘要

The permanent magnet excited electric motor has rotor (10) with permanent magnets (11), that moves relative to stator (8) by the magnetic force of the permanent magnets. A heating device (12) includes heating element such as heating coil or heating resistor to heat permanent magnets of stator, so as to weaken the magnetic field of permanent magnet in response to moving speed of rotor with respect to the stator. An independent claim is included for method for operating permanent magnet excited electric motor.