Dynamic Capacity Expansion Strategy for Expressway Service Area Based on I-NSGA-II Algorithm

When high power density of electric vehicle (EV) charging load connected to the microgrids in expressway service areas, the stability of the system is affected. Long-distance transmission or transformer expansion can be costly and difficult to maintain, therefore, this research proposed a dynamic capacity expansion method. Combined with the energy storage system, through the most economic operation, aiming for strong microgrid independence and minimum power fluctuation, a multi-objective model is established to pursue the optimal dispatch scheme by integration of power assets using the Nondominated Sorting Genetic Algorithm II (NSGA-II). To address insufficient diversity for evolutionary operators and slow speed of the original NSGA-II, improvements are made based on the initial dataset optimization and differential evolution. Verified by the simulating results, the proposed method dynamically expands the capacity of the microgrid, thus mitigates the impact of heavy charging load.