中文摘要：

在光伏并网逆变系统中,常用的双闭环电流控制会导致系统存在动态响应速度慢或开关频率不稳定的缺陷。鉴于此,提出一种电压外环,电流内环,频率中间环的三环控制方法。通过对整个逆变系统进行深入的理论分析,利用Matlab/Simulink搭建仿真模块进行仿真实验,并搭建1kW的实验平台进行实验分析。实验的结果表明,三环控制下的逆变系统简化了滤波器设计,保证了逆变器输出电流波形质量,使其只含有少量的高次谐波,使系统的输出电流和电网电压同频同向,并网的功率因数接近于1。

英文摘要：

In photovoltaic grid-connected inverter system, traditional double-closed loop control method can result in the system dynamic response speed slow and switching frequency instable. Aiming at that, this paper presents a three-loop control method, including voltage external loop, frequency middle loop and current inner loop. The total inverter system is deeply analyzed, simulated module is constructed by using Matlab/Simulink to make simulation experiment, and 1 kW test platform is established to do experiment analysis. The results show that the inverter system controlled by three-loop simplifies the design of filter and guarantees the waveform quality of the output current, which make it contain few high-order harmonics, the system output current and grid voltage have the same frequency and direction, and the power factor after interconnection close to 1. This work is supported by National Natural Science Foundation of China （No. 50977080）.