光伏并网系统配备一定容量的储能装置组成的交流微电网中使用了大量的非线性元件，当微电网中带有大量非线性负载时，易使微电网系统的电流波形出现畸变，产生谐波污染。为减小微电网系统并网对受纳电网的干扰，基于LCL并网逆变器结构，通过PI +重复控制的复合控制策略，在同时满足跟踪速度和精度基础上，实现对指令电流的追踪控制，能够有效抑制谐波电流、补偿无功功率。在复合控制基础上，考虑了光伏输出功率、负载功率突变，研究微电网与电网之间在不同模式下传输的不同功率，结果表明在该复合控制下的多功能并网逆变器依旧可以实现双重功能，最后通过仿真验证，该策略实现了谐波补偿和无功补偿，同时向电网传输功率。

A large number of nonlinear components are used in the AC microgrid of photovoltaic grid-connected system which is equipped with a certain capacity of energy storage devices. When there is a large number of nonlinear loads in the microgrid system, the current waveform of the microgrid system is prone to distortion, resulting in harmonic pollution. In order to reduce the interference of grid-connected microgrid system on the receiving grid, based on the LCL grid-connected inverter structure, PI + repeated control compound control strategy was adopted to realize the tracking and control of command current on the basis of meeting the tracking speed and accuracy, which can effectively suppress harmonic current and compensate reactive power. Based on the composite control, it is considered that when the photovoltaic output power and load power change, the multi-function grid-connected inverter under the composite control can still realize dual functions when the researched microgrid and the grid transmit different power in different modes. Finally, the simulation results show that the strategy realizes harmonic compensation and reactive power compensation, and transmits power to the grid at the same time.