基于PI+重复控制的光伏并网逆变器设计

Design of Photovoltaic Grid-connected Inverter Based on PI and Repetitive Control

本文通过实验指出数字PI控制器在光伏并网逆变器中的局限性,提出将重复控制器引入到电流内环中以提高稳态性能,进而将重复控制和PI控制器并联用于三相光伏并网逆变器的电流波形控制。其中PI控制保证系统动态性能,而重复控制提高电流波形跟踪精度。实验表明,采用这种方法后可以显著改善逆变器的并网电流质量。

In this paper, it is pointed out through experimental result that the digital PI controller is in the limitations in the photovoltaic inverter, and it is proposed that repetitive controller is introduced into current loop to improve the steady characteristics. So PI control and repetitive control algorithm are adopted to correct the output current waveform of the photovoltaic grid-connected inverter. In this control strategy, the PI control is used to guarantee system dynamic performance and the repetitive control is to improve current waveform quality. The experimental results show that this controller design can significantly improve the grid-connected current aualitv.