Analysis of an adaptive observer for sensorless control of PMSM drives

The paper deals with a speed and position estimation method for the sensorless control of permanent magnet synchronous motors. The method is based on a speed-adaptive flux observer augmented with a high-frequency signal injection method at low speeds. The dynamics of the adaptive observer are analyzed by linearizing both the motor model and the observer, and the observer gain is selected to give improved damping and noise suppression. The experimental results are in agreement with the results of the analysis.