Intermittent Inductance Estimation for High-Speed PMSM Sensorless Control

To achieve a high control performance, parameter information is necessary for accurate control. However, inductance values vary depending on the load and operation modes. Furthermore, the computation time is often insufficient for parameter estimation. In this work, a simple and straightforward inductance estimation method is proposed that injects a probing voltage for the high-speed SPMSM drives. The parameters are estimated by measuring the d−q axis current derivatives caused by the injected voltage. With the proposed scheme, a whole PWM period is reserved intermittently for inductance estimation in the high-speed operation. Therefore, the main control voltage is not output in the periods of estimation, causing current distortion. However, the magnitude of distortion looked minor due to the high control bandwidth. Validity of the method was demonstrated through simulation and experimental results.