基于电流无差拍控制的单相光伏并网逆变器研究

摘要

在单相光伏逆变并网系统中,由于传统控制器电流动态响应速度慢,使得在电流发生变化时容易产生谐波污染电网,不能满足越来越高的电能质量要求.通过对单相光伏并网逆变器模型的研究,采用一种基于电流无差拍的控制方法,推导出其离散传递函数,并对其进行稳定性分析.在降低稳态误差和提高抗干扰能力的同时使得电流的响应速度提高,并且降低了逆变器并网电流的总谐波畸变率.最后通过仿真和实验验证了理论的正确性和控制方法的有效性.%Due to its slow current response speed,the traditional controller in single-phase photovoltaic grid-connected inverter system makes it easy produce the harmonic pollution in the electric current change,which can hardly meet the requirements for higher power quality. By studying the single-phase photovoltaic grid-connected inverter model and adopting a control method based on the current deadbeat,the discrete transfer function is deduced and its stability analysis is conducted. In the course of reducing the steady-state error,the anti-interference ability of the current response speed has been improved,and the inverter grid current total harmonic distortion has also been reduced. Finally both the correctness of the theory and the effectiveness of control method is verified by simulation and experiment.