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.