Coordinated planning method of multiple micro-grids and distribution network with flexible interconnection

This work explores the coordinate planning methods for multiple micro-grids in different distribution transformers and networks with flexible interconnections. The optimal planning model considers in detail the coupling influence of the interconnection structure, investment, installed capacity and annual operation cost. The interconnection structures of multiple micro-grids with different distribution transformers are discussed, and the flexible interconnection device (FID) model is established. Then, multiple micro-grids with the FID interconnection planning model is proposed, which is considered to include the connection type, investment cost and hourly operation dispatches. In order to solve the complicated combinatorial bi-level layer planning model, the benders decomposition methods are used to divide the problem into an investment decision-making master problem and an operation optimal sub-problem. A study case which is based on six micro-grids in three distribution transformer areas is used to carry out the planning methods, and simulation results show that the proposed model and methods are effective, and have some technical and economic advantages.