Self-tuning discrete sliding mode control of a closed-loop regulated PWM inverter with optimal sliding surface

This paper presents a self-tuning discrete sliding mode control scheme with feedforward compensation for the closed-loop regulation of PWM inverters used in uninterruptible power supplies (UPS). A self-tuning scheme is proposed to adjust the parameters of both the feedforward and sliding mode controllers. In designing the sliding mode controller, the authors have taken the effect of load disturbance into consideration to enhance the robustness of the controlled system. The sliding surface of the sliding mode controller is designed such that the behavior of the controlled PWM inverter system is optimal, subject to the defined cost function. Simulation and experimental results are given to show the superiority of the proposed control scheme.