Decentralised L1 Adaptive Controllers for Voltage Control of DC Islanded Microgrids

Voltage stability is a critical feature of an efficiently operating power distribution system such as a DC islanded microgrid. Large-scale autonomous power systems can be defined by heterogeneous elements, uncertainty and changing conditions. This paper proposes a novel scalable decentralised control scheme at the primary level of the typical hierarchical control architecture of DC microgrids with arbitrary topology. Local state-feedback \mathcal{L-{1}} adaptive controllers are retrofitted to existing baseline voltage controllers of DC-DC boost converters, which interface distributed generation units with loads. The use of \mathcal{L-{1}} adaptive controllers achieves fast and robust microgrid voltage stability in the presence of dynamic uncertainty and plug-and-play operations. Furthermore, local controller synthesis is modular, as at most, it requires approximate information about line parameters that couple neighbouring units.