Sliding mode control of the speed loop for PMSM based on variable parameter reaching law and adaptive observer

To improve the speed control performance of the permanent magnet synchronous motor (PMSM) drive system, a sliding mode control strategy based on variable parameter reaching law (VPRL) and adaptive disturbance observer is proposed. The VPRL introduces state variables into the conventional exponential reaching law (CERL) and designs a power term function related to the arctangent function. In response to the issue of poor performance in traditional Luenberger disturbance observers (LDOB), by introducing an adaptive function that represents the relationship between system state variables and parameters into the traditional LDOB, an adaptive Luenberger disturbance observer (ALDOB) is proposed to estimate and compensate for the total disturbances in the system. Simulations and experiments demonstrate that the proposed sliding mode control strategy significantly improves both the dynamic performance and robustness of the PMSM.