Decoupled average model-based sliding mode current control of LC-filtered inverters in rotating frame

Recently, LC-filtered inverter has been a trendy research object towards the efficient exploitation and use of sustainable energy sources. The nested control scheme of the system includes a voltage control loop and a current one, which can be developed on the rotating frame. The conventional PI controller is employed for the outer loop voltage controller and it performs effectively. However, the PI current controller introduces delay to the system and overshoot occurs frequently due to the influence of nonlinear load. This paper proposes a novel method of decoupled average model-based sliding mode current control performing faster response and better tracking performance of the desired current. Besides, the comprehensive model of the nonlinear load is applied to examine the robustness of the proposed control scheme. This method is developed on the average model, fixed-frequency PWM can therefore be used to modulate the inverter. The novel method is compared with a conventional PI current controller. Offline simulation on MATLAB/Simulink and real-time simulation using Opal-RT experimental platform prove the advantages of the proposed current controller considering critical scenarios with the nonlinear load.