Distributed control for interconnected DC microgrids with enhanced dynamic voltage performance

The DC bus voltage serves as a critical performance metric for interconnected DC microgrids (MGs), particularly in those supporting critical loads. Voltage deviations beyond the acceptable threshold may cause load malfunctions or even cascading failures. The distributed control architecture is recognized as a promising solution due to the superior steady-state control capabilities. However, seldom research has been conducted to enhance the dynamic performance under the distributed architecture. To this end, a weighted voltage control is proposed in this paper to regulate the bus voltages of MGs with distinct load priorities. The dynamic voltage performance of MGs is balanced under identical priority levels; otherwise, high-priority MGs show better voltage performance. By deploying the proposed voltage observer at the IC port, active participation of the IC in MG voltage regulation is achieved. Moreover, the virtual inertia control and distributed secondary control are considered together in MG to strengthen the inertia. Next, the small-signal analysis supports the parameter selection for the proposed control scheme. Finally, the hardware-in-the-loop (HiL) testing validates the effectiveness of the proposed control strategy. • A weighted voltage control for interlinking converters balances subgrid dynamics and improves system performance, prioritizing voltage quality via adjustable weights. • A consensus-based voltage observer enables flexible DC microgrid voltage regulation. • A virtual inertia hierarchical control enhances bus voltage inertia with steady-state performance guaranteed.