Improved Dynamic Performance for Sensorless PMSM Control Using Hybrid Active Flux Observer with Load Torque Observer

To address the problem of low accuracy and susceptibility to load disturbance, this paper combines active flux observer and sliding mode load torque observer to improve the performance of sensorless control of Permanent Magnet Synchronous Motor (PMSM). First, this paper proposes an active flux observer based on hybrid model of voltage and current to achieve the stable operation of PMSM sensorless. Second, to improve dynamic performance under abrupt load torque variations, a sliding mode load torque observer is designed to estimate the load torque, which is then integrated into the current loop as a feed-forward compensation term. The simulation results show that the adopted flux linkage observer has a high position observation accuracy, and the adopted load torque feed-forward compensation strategy can effectively suppresses speed fluctuations caused by abrupt load torque variations, enhancing the anti-interference ability of the control system.