Impedance and Admittance Specifications for Small-Signal Stability of Multi-bus DC Distributed Power Systems

Currently, the scale of dc distributed power systems (DPSs) keeps growing, which makes the number of the buses larger and the stability analysis more complex. In this paper, impedance and admittance specifications of multi-voltage-level dc DPS that restricts impedance or admittance of the bus-connected converters or subsystems and the transfer function of intermediate bus converter (IBC) is proposed and studied. A two-voltage-level dc DPS experiment platform is constructed to verify the specifications. It is proved that the specifications are able to ensure the stability of the multi-voltage-level dc DPS, and thus guarantee the designing process of the parameters are decoupled and decentralized. It solves the problems of the cost and the timeliness of every converter, subsystem and IBC’s information transmission and the curse of dimensionality that extensively exist in the stability analysis of multi-voltage-level dc DPSs.