逆变器的输出滤波对于电网安全工作尤为重要。首先对并网逆变器的滤波器进行研究, 导出了LCL滤波器的传递函数, 分析了不同参数变化对传递函数的影响。其次基于电路模型、传递函数及谐波分量的特点, 介绍了LCL滤波器的设计方法并给出了消振措施。最后根据并网控制系统, 建立光伏并网系统的仿真模型, 对系统输出进行仿真, 得到较好的仿真数据, 实验证明了这种LCL滤波器设计方法的优越性。

The high frequency pulse width modulation controlling is mainly used in the photovoltaic grid-connected inverter, which results in a large number of high-order harmonic current into the power grid. Therefore the filtering in the output of the inverter is fairly important.In this paper, different grid inverter filters were analyzed and general filter transfer function was derived from the filter network circuit diagram. Then the effects on the entire transfer function caused by different parameter changes is also analyzed. A design method of LCL filter with damping measures, which is based on the circuit model, transfer function and characteristics of harmonic components, is introduced in this article. Lastly, matlab simulation and experiment are conducted.