Low speed sensorless control and initial position estimation of synchronous reluctance motors based on system identification theory

In this paper, we propose a position estimation method for synchronous reluctance motors in standstill and low-speed ranges. We derive a mathematical model considering magnetic saturation and an estimation method using this model. The proposed method is based on the system identification theory and uses the relation between voltages and currents of a mathematical model. Since the proposed method can estimate rotor position from only voltages and currents, any motor parameters are not necessary at all and estimated position are not affected by variation of motor parameters. Additionally, the proposed method can use information of all frequency band. Therefore, any band-pass filters are not necessary The proposed estimation method is verified by experiments.