A novel control method for suppressing the disturbance of line voltage on the photovoltaic inverter

In this paper, a new grid voltage disturbance rejection scheme with feed-forward control based on the dual closed loop current control strategy is presented. As a means to eliminate the level of low-order current harmonic distortion, the proposed method uses the inner loop capacitor current as the feed-forward variable (CCFF). This strategy can suppress the current harmonics arising from the grid voltage distortion effectively, and the steady-state error of the output current can be substantially reduced. Meanwhile, it is uncomplicated to the system parameters design, so it is a low cost, high reliability control strategy. The system transfer function with this control strategy is deduced, and the system stability is analyzed. Finally, the simulations and experiments demonstrate the feasibility and effectiveness of the proposed control strategy.