Distributed secondary optimal control for self‐maintaining microgrids on pelagic islands

Abstract

Abstract Considering the geographic distance, self‐maintaining microgrids are widely built to supply power on pelagic islands, where developing distributed autonomous control strategies while guaranteeing microgrids’ resilience and energy security have gained increasing attention. However, most existing distributed control strategies restore frequencies in an asymptotic manner, which may not meet the requirement for safe and rapid recovery after disasters. Meanwhile, self‐maintaining microgrids have relatively low percentages of fossil fuels. Power sharing among distributed energy sources (DERs) under most existing control relies on the droop coefficients, which may lead to inefficient operations. To overcome these challenges, this paper proposed a distributed control strategy for self‐maintaining microgrids. The frequency restoration time can be explicitly optimized and is robust to changes of system states, which provides faster recovery performance under disasters. The steady‐state powers of different DERs are regulated for different kinds of DERs separately and are independent of the droop coefficients, where the proper use of renewable energy under energy security can be achieved. The proposed control enhances the resilience of microgrids against disasters and meets the requirement of energy security on islands. The algorithms in the paper are verified by both simulation and experiment studies under various conditions.

Keywords

• distributed control
• frequency control
• microgrids