A Two Stage GA-MILP-based Sizing Optimization Method for Off-grid Integrated Energy System

Capacity configuration optimization is one of the primary tasks in the construction of the integrated energy system (IES). the uncertainties of renewable energy sources and loads deepen the coupling relationship between the capacity configuration and energy dispatching of IES, which makes optimizing the capacity difficult. This paper proposes a two stage GA-MILP-based capacity sizing allocation method for off- grid IES. Firstly, a double-layer capacity configuration framework based on Leader-Follower is constructed. Secondly, the genetic algorithm (GA) is used to randomly generate the initial configuration in the Leader layer and use it as the input of the Follower layer. In the Follower layer, the system investment cost, operation cost, and maintenance cost are comprehensively considered, the mixed integer linear programming (MILP) method is used to obtain the minimum operating cost and energy dispatching scheme and then return to the Leader layer. The optimal capacity configuration scheme is obtained through multiple iterative optimizations. Finally, the proposed method is applied to an Off-grid island to confirm the rationality and effectiveness of the optimization results.