A novel adaptive sliding mode control of PWM rectifier under unbalanced grid voltage conditions based on direct power control

To deal with the control problems of the three-phase PWM rectifier under the unbalanced grid voltage conditions, this paper proposes a modified direct power control strategy using adaptive sliding mode control algorithm with model of the PWM rectifier in stationary αβ frame. The active and reactive power dynamics of the PWM rectifier are linearized and decoupled based on the inverse system algorithm. Then a sliding mode control scheme is designed to improve the robustness and reduce the influences caused by the system parameters variations and load disturbances. In order to satisfy the state requirements, an adaptive law is introduced to the control strategy to reduce the sliding mode control gain on the premise that the system is stable. Simulation results confirm the feasibility of the proposed control strategy.