Integrated emergency control strategy for single/three-phase hybrid microgrid group coupling load correlation factors and under-frequency load shedding

Abstract

Under-frequency load shedding is a necessary measure for the elimination of power shortages in a single/three-phase hybrid microgrid group under unintentional islanding. To date, research studies have considered virtual three-phase combination, load evaluation, and load shedding separately, rather than as in integrated whole. Therefore, an integrated emergency control strategy for a single/three-phase hybrid microgrid group with coupled load correlation factors and under-frequency load shedding is proposed in this paper. First, to reduce the complexity of the model and shorten the time needed to obtain the load shedding decision, an integrated emergency control strategy framework for coupled virtual three-phase combination-load evaluation-load shedding is constructed based on the meta-model. Second, a multistrategy ant lion optimization (MSALO) algorithm is designed, which combines the Lévy flight mutation mechanism and the golden sine search strategy and updates the optimization position parameters to enhance the global optimization capabilities and local optimization efficiency. This algorithm is applied to the correction and dynamic updating of the meta-model parameters, aiming to generate optimal emergency control decisions. Finally, the proposed strategy is validated using the improved IEEE-37 node and the improved IEEE-118 node single/three-phase hybrid microgrid group models. The simulation results show that the proposed strategy can reduce the economic loss and three-phase imbalance degree during the emergency control period, reduce the frequency fluctuation range and the frequency recovery time, and improve the response speed of emergency control decision-making.