Bi-Level Method of Islanded Microgrid Optimal Sizing Based on Life Cycle Cost

To solve the problem of optimal allocation of islanded microgrid, a bi-level method based optimal sizing model is proposed in this paper. The optimal sizing model in upper level gives the optimal configuration strategy. The upper level optimization aiming at the annual investment cost during the life cycle is solved by the improved decimal genetic algorithm. Daily operation cost minimization and renewable energy utilization rate maximization of the microgrid is conducted in lower level based on the optimal dispatch model, which can be solved through a mixed integer linear programming method. Considering the operation constraints of microgrid, the proposed algorithm is applied to an islanded microgrid in Nanchang, Jiangxi province, showing the effectiveness and accuracy of the proposed optimal configuration strategy. Meanwhile, the impacts on the optimal configuration strategy brought by the energy storage system is also analyzed.