Large-Signal Stability Control for Multiple Cascaded Filter DC Microgrid Based on Modified IDA-PBC

Multiple cascaded filters can lead to instability in DC microgrids. To address this issue, this paper proposes a stabilization strategy for a DC microgrid with multiple cascaded filter subsystems. Stability is achieved by considering the cascaded input and output filters at the subsystem level and establishing a modified Interconnection and Damping Assignment Passivity-Based Control (IDA-PBC) strategy based on port-controlled Hamiltonian modelling. First, the general design procedure of the proposed control strategy and its large-signal stability proof are presented, and the stability of the entire microgrid is proved. Second, an example design of the controller considering the cascaded input and output filters source subsystem is given. Finally, the modified IDA-PBC strategy is applied to the basic unit of the DC microgrid, which includes the source subsystem of the cascaded input and output filters and the load subsystem of the cascaded input filter. The modified strategy is further applied to a complete DC microgrid containing multiple subsystems. The experimental results and hardware-in-the-loop results indicate the effectiveness of the proposed strategy.