Active-reactive power coordination for DC-interconnected microgrid clusters: a small-signal stability perspective

Unstable power exchange and voltage fluctuations at the PCC frequently compromise the operational stability of DC microgrid clusters. In response to these challenges, a coordinated control framework is developed wherein ICs actively cooperate with distributed sources within sub-microgrids. Distinct from conventional approaches, the proposed strategy enforces a global equilibrium for active power across the entire cluster, whereas reactive power regulation is confined to the local sub-microgrid level. To evaluate the system stability, a comprehensive small-signal model tailored to this specific control architecture is constructed. Simulation results under light-load, reactive heavy-load, and active heavy-load scenarios demonstrate the effectiveness of the proposed method. The findings underscore the capability of ICs to effectively track power flow targets without compromising the voltage stability at the PCC.