光伏并网系统的输出电流控制方案

Control program of output current based on photovoltaic grid system

光伏并网输出电流有两个重要指标,为了减少电网受到的谐波污染,需减小谐波电流失真(THD);为了减少电网无功损耗,需提高功率因数。设计模拟和数字式两种控制方法实现并网,在相同的控制参数下进行SIMULINK仿真,并对比控制效果。结果证明,模拟式控制的THD为1.5%,数字式控制的THD为5%,并为模拟控制提出了可行方案。

The output current of photovoltaic has two important indicators. In order to reduce the harmonic pollution of power system, THD needs to be reduced; also, power factor needs to be increased to reduce the reactive loss of power system. In this paper, analog and digital controllers were separately used to adapt the inverter to grid power system. After testing the simulation by using simulink with the same parameter and different controllers, the discrepancy of control effect between two types of controller was compared. The results show that THD of analog system is 1.5%,and the one of digital system is 5%. A feasible program for the analog control was proposed.