【摘要】 直流微电网集群通常由多个直流微电网互联而成，通过灵活的功率流动控制实现区域能源共享和优化利用，以充分发挥直流分布式发电系统的优势。然而，小规模直流微电网具有低惯性和高阻抗的“弱电网”特性，“弱-弱”互联会降低集群系统的阻尼，甚至出现振荡或系统崩溃等严重后果。同时，直流微电网集群的高阶、强耦合以及非线性动态特性也对其稳定性分析带来了巨大挑战。为此，基于Brayton-Moser混合势理论，提出针对直流微电网集群的大信号稳定性分析方法。建立集群的大信号降阶模型，详细推导用于系统大信号稳定性判据的混合势函数，并分析关键参数对稳定区间的影响，最后通过实时仿真结果验证了该分析的正确性。更多还原

【Abstract】 DC microgrid(DCMG) clusters are in general formed by interconnecting multiple DCMGs to achieve zonal energy sharing and optimized utilization through flexible power flow control,and thus the advantages of DC-based distributed generation systems can be fully exploited. However,small-scale DCMGs are weak grids of low inertia and high impedance, and hence the weak-weak interconnection will reduce the damping of DCMG clusters, and even lead to severe consequences like oscillation and system collapse. In the meantime, the dynamic characteristics of higher-order, strong coupling, and nonlinearity bring great challenges to the stability analysis of DCMG clusters. To address this issue, a method for large signal stability analysis of DCMG clusters was proposed based on Brayton-Moser mixed potential theory. The large signal reduced-order model of the DCMG cluster was built, and the mixed potential function that facilitates large signal stability criterion was derived in detail, and the influence of the critical parameters on the stability region was analyzed. The correctness of the analysis is verified by real-time simulation results.更多还原