Optimal Capacity Configuration Method for Multi-Microgrid System Utilizing Wind-Solar-Electric-Hydrogen Hybrid Energy Storage

ObjectivesIn order to study the problems of increasing complexity of power balance, and increasing uncertainty of power flow distribution and increasing security and stability requirements of power grid caused by high proportion of renewable energy access, a capacity optimization configuration method of multi-microgrid system including wind power, photovoltaic, battery and hydrogen energy storage is proposed.MethodsA bi-level optimization model is established under the framework of multi-microgrid distribution network. The outer objective of the model is to minimize the life cycle cost, and the inner objective is to minimize the peak-valley difference, network loss and voltage offset of the distribution network. Based on the IEEE 69-bus system, the white shark optimizer (WSO) algorithm and Cplex solver were used to solve the model, and the optimal capacity configuration scheme and planning operation results are obtained. Finally, case analysis is carried out through different energy storage combinations.ResultsWhen the capacity configuration of each component of the system is optimal, the installed ratio of the wind-solar power generation system to the hybrid energy storage system is 1∶0.27. The wind-solar-electric-hydrogen hybrid energy storage system is superior to the wind-solar-single energy storage system in terms of economy and stability.ConclusionsThe proposed method can not only optimize the joint optimal cost of the system, but also effectively reduce the load peak-valley difference, distribution network loss and improve the power quality.