Load disturbance observer-based control method for sensorless PMSM drive

This study proposes a sensorless control method for the permanent magnet synchronous machine (PMSM) drive that is robust against load torque variations. The proposed method is based on the disturbance observer-based control (DOBC) method, and involves the use of a back electromotive force observer and a torque observer to estimate rotor position and compensate for load torque disturbance, respectively. This mechanism is simple to implement and requires no state vector derivation. The gains of the two observers are carefully selected to improve estimation accuracy and dynamic performance. The performance of the proposed load DOBC for sensorless PMSM drives was tested through a simulation, where the sensorless estimation error was considered to determine the adjustment laws for the proposed observer gains. Furthermore, results of evaluative experiments verified the effectiveness of the proposed method for high-performance sensorless control and torque disturbance rejection for the PMSM drive.