由于光伏变流器、储能变流器和各种用电负荷的开关电源等电力电子设备的负电阻特性，导致环形直流分布式电源系统(distributed power system, DPS)的小干扰稳定性面临着严峻的挑战，而基于传统阻抗模型与状态空间模型在分析环形直流DPS时尚存在一定局限性。文中基于阻抗（导纳）网络的无源特性，建立系统的RLC（resistance inductance capacitance）无源网络模型与具有相同开环稳定特性的负反馈系统，从而将RLC阻抗网络模型应用于DPS稳定性预判与设计，通过一个包含6变流器的直流DPS验证了文中所提方法的有效性。经过理论分析和实验结果验证，该方法在系统稳定性判别与设计方面展现出了显著的优势。
英文摘要:
Due to the negative resistance characteristic of power electronic device such as photovoltaic converter, energy storage converter, and switching power supplies for various electrical loads, the small-signal stability in ring DC distributed power system (DPS) is facing challenge. However, the analysis methods based on traditional impedance model and state space model have some limitations when applied to stability analysis for DPS. The impedance network model and negative feedback system with a stable open-loop function of system are established based on the impedance (admittance) characteristics of the converter ports, then, the stability judgment and design for the DPS is applied by the impedance network model. Finally, the validity of the proposed method is verified by DC DPS with 6-infeed converters. The theoretical analysis and experimental result show that the proposed method has a good advantage in stability judgment and design for DPS.