Current control of a PWM inverter using sliding mode control and adaptive parameter estimation

This paper proposes an approach to control the current amplitude and phase of a PWM inverter simultaneously. To do this, sliding mode control and adaptive parameter estimation are applied to the current control of a single-phase PWM inverter with unknown R-L series load. The load parameters, R and L, are estimated by using the recursive least square method and these parameters are used to adjust the feedback gains of control input. The inverter system is modelled in a second-order system by treating load current variation caused by inductive component as a disturbance. A DSP-based (TMS320C30) PWM inverter controller is implemented to verify the effectiveness of the proposed control scheme. Simulations and experiments based on the second-order model show good dynamic response and low THD