Sensorless control of permanent magnet synchronous motor employing extended Kalman filter in combination with HF injection method

This paper presents sensorless control of PMSM in full speed range employing combination of two estimators: (i) hf injection, and (ii) extended Kalman filter (EKF). Pulsating hf injection algorithm ensures position and speed estimation in low speed region including standstill. EKF provides precise estimation of rotor speed and position in higher speeds. Algorithms are switched between each other with hysteresis algorithm which guarantee reliable transitions between two algorithms without oscillations and disturbances. Behavior of proposed sensorless control is analyzed by extensive sets of experiments on servo drive of rated power of 10.7kW.