Disturbance-Observer-Based Second-Order Sliding Mode Controller for Speed Control of PMSM Drives

This paper explicitly proposes a novel second-order sliding mode (SOSM) controller based on disturbance observer (DOB) to optimize the disturbance rejection property of the permanent magnet synchronous motor (PMSM) system. Firstly, to tackle the inevitable chattering problem in conventional first-order sliding mode controllers, a new type of SOSM control technique is designed for the speed loop of PMSM system by retaining the discontinuous switching function in the derivative of the actual controller. The proposed controller can not only provide the strong anti-disturbance performance, but also significantly attenuate the potential chattering problem. Then, a DOB constructed based on the auxiliary system is further adopted to compensate the adverse effect generated by the disturbance to enhance dynamical performance. Finally, comprehensive experimental results are provided to verify the effectiveness of the proposed method.