In the weak current network environment, the existence of power network impedance will reduce the current control stability margin of LCL grid connected inverter, the stability margin will gradually deteriorate as the inductive component of the power network impedance increases, leading to system instability. In this paper, an improved weighted average current control strategy is proposed, which is based on the active damping control of the voltage feedforward of the charged network. In the new control strategy, with the zero-pole cancellation method, a new weighting coefficient related only to the parameters of LCL filter is obtained, which reduces the order of the system, suppresses the influence of power network impedance, and improves the stabilization of the system, getting better inverter output current quality. Then the influence of power network impedance on the control system of grid connected inverter is analyzed, and the feed-forward control of grid voltage is improved to improve the stability of inverter in weak current network. The Bode diagram analysis and MATLAB simulation results proved that the proposed control strategy is feasible.

中文翻译：

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基于电网电压前馈的主动阻尼控制的加权平均电流法

在弱电流网络环境下，电网阻抗的存在会降低LCL并网逆变器的电流控制稳定裕度，随着电网阻抗的感性分量增加，稳定裕度将逐渐下降，导致系统不稳定。本文提出了一种改进的加权平均电流控制策略，该策略基于带电网络电压前馈的主动阻尼控制。在新的控制策略中，采用零极点抵消方法，获得了仅与LCL滤波器参数有关的新加权系数，从而降低了系统阶数，抑制了电网阻抗的影响，提高了电网的稳定性。系统，变频器输出电流质量越来越好。然后分析了电网阻抗对并网逆变器控制系统的影响，改善了电网电压的前馈控制，提高了逆变器在弱电网络中的稳定性。Bode图分析和MATLAB仿真结果证明了所提出的控制策略是可行的。