A Torque-Injection-Based Method for Stator Temperature Estimation of Direct-Torque-Controlled Permanent Magnet Synchronous Motors

摘要

This paper proposes a method to estimate the stator winding temperature of permanent magnet synchronous motor (PMSM) driven by direct torque control (DTC) strategy, where the stator resistance is used as a direct indicator of the temperature. In this method, the quantitative relationship betw een the dc current offset and the corresponding changes in torque is derived. The dc current offset is generated by injecting the toque signal into the torque control loop of the DTC system of the PMSM to calculate the stator resistance. The stator winding temperature is estimated by the relationship between the stator resistance and the stator winding temperature. The simulation results validate the effectiveness of the proposed method. In addition, the proposed method requires no extra experimental equipment and has little effect on the normal operation of the PMSM.