Decentralized impedance/admittance specifications for DC distribution power system with two-voltage-level buses

The multiple-bus dc distribution power system (DPS), which offers better power density, control flexibility, and reliability, is an improvement on the single-bus dc DPS system. However, the additional buses also complicate the system's stability evaluation. The decentralized impedance/admittance specifications for dc DPSs with two-voltage-level buses are proposed in this paper. Once the specifications are satisfied, the system is stable. This method systematically sets limits on the amplitudes of input/output admittance and transfer admittances of the intermediate bus converter (IBC) as well as the impedance/admittance of each bus-connected converter/subsystem. To confirm the correctness and effectiveness of the suggested scheme, a two-voltage-level dc DPS experiment platform is established. This method offers design instructions for converters/subsystems. It avoids impedance coupling, complex calculation, and the accompanying problems of them, such as the curse of dimensionality, high cost and non-timeliness of transmission in multi-voltage-level dc DPS, and is also applicable in black-box system.