Sensorless combined control of IPM motors using extended flux model

This paper proposes a sensorless combined control method for IPM motors in a wide speed range using an extended flux model without signal injection. In this method, the stator flux linkage, rotor position, and speed of IPM motors are estimated. The estimation is mainly carried out in a stationary reference frame with minimal dependency on the current components in a rotating reference frame, resulting in more accuracy compared to the conventional one. The method enjoys simplicity, high accuracy in low speed range, and robustness against system parameters variation. The estimation is employed in a combined control system and applied to an IPM motor. Comparative simulation results confirm effectiveness of the proposed sensorless control system and its superiority over a control system based on an existing estimation method.