Two-level Capacity Optimization Strategy for Generations in Multi-energy Gathering Center Considering the Flexibility

As traditional optimal planning strategies in multi-energy gathering center are only dominated by the economic index, while the flexibility index has not been taken into consideration. This paper creatively proposes a comprehensive evaluation metric of flexibility and economic index based on the multi-scenario operation process and the optimal planning method. A two-level capacity optimization model of different generations in multi-energy gathering center is established in this paper. This model consists of two objectives, the economy index and the flexibility index. The outer model applies the capacity of two flexible resources, thermal power units and battery energy storage units, as decision variables. And the inner model aims at the operating cost and flexibility index as objectives. The combined method of NSGA-II, linear programming and quadratic optimization is adopted to solve the above two-level optimization problem on the basis of fully considering multiple scenarios. Finally, based on the actual data and energy characteristics in a multi-energy gathering center in Yunnan, the proposed planning strategy is verified. Simulation results show that, compared with the traditional planning strategy only considering the economic cost as the main index, this proposed strategy can significantly reduce the energy abandonment and loads’ cutting rate. As a result, the proposed strategy reduces the possibility of grid risks and improves the system reliability and flexibility.