中文摘要：

为减弱电网谐波电压对LCL并网逆变器电流控制性能的影响，多采用电压前馈控制。当电网较弱时，电压前馈控制和电流控制之间的耦合将影响系统的幅值稳定裕度和相位稳定裕度。从理论上分析了电压前馈控制对电流环控制稳定性的影响，并分析了该影响与逆变器数量的关系。为改善弱电网下电流控制性能，在此提出一种改进的电流控制策略。仿真和实验结果验证了所提控制策略的可行性和有效性。

英文摘要：

To suppress low-frequency current harmonics,a grid-voltage feedforward control is commonly used.The magnitude and phase margins are affected by the coupling between voltage feedforward control and current control.The stability of the current loop influenced by the voltage feedforward control and the relationship between the impact and the number of grid-connected inverters are analyzed.To improve the control performance of the current in the weak grid case ,an improved current control is proposed.Simulation and experimental results are provided to verify the feasibility and validity of the proposed strategy.