针对传统下垂控制中储能单元变换器输出电流分配不均及电压跌落问题，提出了一种改进方案。首先在传统下垂控制基础上引入交流小信号扰动，构建频率-电流复合下垂控制策略，实现直流微电网中分布式电源变换器的精确比例电流分配；其次，基于混合势函数理论推导改进下垂控制下微电网的大扰动稳定性判据；最后，通过MATLAB/Simulink仿真验证表明，所提出的频率下垂控制策略能有效实现变换器电流的精确分配，同时稳定性判据正确有效，并确定了特定直流微电网结构参数下的恒功率负载突增临界范围及电压控制器参数可行域。

To address the issues of uneven output current distribution and voltage drop in energy storage unit converters under traditional droop control, an improved scheme is proposed. Firstly, an AC small-signal disturbance is introduced on the basis of traditional droop control to formulate a frequency-current composite droop control strategy, achieving precise proportional current distribution among distributed power converters in DC microgrids. Secondly, the large-signal stability criterion for microgrids under the improved droop control is derived based on mixed potential function theory. Finally, MATLAB/Simulink simulations demonstrate that the proposed frequency droop control strategy effectively achieves accurate current distribution in converters while validating the correctness and effectiveness of the stability criterion. Additionally, the critical range for sudden increases in constant power loads and the feasible domain for voltage controller parameters are determined for specific DC microgrid structural parameters.