A Torque Compensation Method Considering Temperature Variation of SPMSM

This paper analyzed the effect of temperature on the permanent magnet flux and output torque. The major parameter which will impact the torque control accuracy of a surface mounted permanent magnet motor is the variation of the permanent magnet temperature. In addition, the temperature variation of the permanent magnet will also influence the maximum torque per ampere of the motor. To analyze the effect of temperature on the permanent magnet, the rotor of the motor was directly heated to measure the temperature and the permanent magnet flux was measured. As a result, the output torque of the motor decreases as the temperature of the rotor permanent magnet increases. Therefore, this paper proposes a technique to compensate the phase current of the motor by estimating permanent magnet flux, and it is proved through theoretical basis and several experiments.