弱电网环境下由于电网阻抗较大，多逆变器并联系统中电网与各逆变器之间的耦合程度增强，导致系统稳定性下降甚至失稳。鉴于此，提出了一种弱电网下多逆变器并网系统稳定性提高策略。首先，建立了弱电网下单台和多台并网逆变器诺顿等效模型。然后，从并网电流稳定性角度出发并基于等效电网阻抗概念将多逆变器系统稳定性判据解耦为单逆变器系统的稳定性判据，明晰了弱电网下系统稳定性降低机理。进而提出了一种提高多逆变器系统稳定性的改进控制策略，通过在电网电压前馈环节引入全通滤波器提高并网逆变器稳定裕度，结合谐波控制器增强系统对背景谐波的抑制能力。最后，通过仿真分析验证了所提策略能有效提高弱电网下多逆变器并网系统的稳定性。

In weak grid environments, the larger grid impedance enhances the coupling between the grid and each inverter in a multi-inverter parallel system, resulting in decreased system stability or even instability. To address this, a strategy for improving the stability of multi-inverter grid-connected systems under weak grid conditions is proposed. Firstly, Norton equivalent models for single and multiple grid-connected inverters in weak grids are established. Secondly, from the perspective of grid-connected current stability, the stability criterion for the multi-inverter system is decoupled into that of a single-inverter system based on the concept of equivalent grid impedance, clarifying the mechanism behind the reduced system stability in weak grids. Subsequently, an improved control strategy to enhance the stability of the multi-inverter system is proposed, which increases the stability margin of grid-connected inverters by introducing an all-pass filter into the grid voltage feedforward loop and combines a harmonic controller to improve the system's ability to suppress background harmonics. Finally, simulation analysis verifies that the proposed strategy effectively enhances the stability of multi-inverter grid-connected systems under weak grid conditions.