A multi-objective joint planning of transmission channel and energy storage system considering economy and flexibility

The uncertain output of renewable energy requires the power system to have flexible adjustment ability, which is called as flexibility. However, current research on power system flexibility planning mainly focuses on power supply configuration and rarely considers the flexibility of line planning. Because of it, this paper proposes a joint planning method of transmission channel and energy storage system considering the dual objectives of economy and flexibility. The model adopts a two-layer optimization model. The upper layer takes the optimal economy and flexibility as the goal, which decides the line planning scheme; while the lower layer is optimized for operational economy, determining the power system scheduling strategy, and returns the results to the upper layer. The model is solved by the NSGA2 optimization algorithm, so the multi-objective optimization is achieved. On this basis, a method of constructing renewable energy output scenes according to fluctuation randomness is proposed, which provides data basis for the planning optimization model. Finally, the method is simulated in the power grid with high proportion of renewable energy to verify the effectiveness.