Steady-state Error’s Suppression Strategy for Continuously Frequency-Adjustment Inverter

In the conventional PI controllers, the output can't track the sinusoidal signal with zero steady-state error, and the output can only track the single frequency sinusoidal signal with zero steady-state error using PR controllers. Therefore, in order to suppress the steady-state error of the output voltage under continuous frequency conversion, a variable parameters quasi-PR control strategy is proposed in this paper. It can be found that the proposed control method can suppress the output steady-state error effectively by comparing the output steady-state error rates under conventional PI control and variable parameters quasi-PR control. Finally, the effectiveness of the proposed control strategy is verified by simulation results.