Optimal Power Transfer Limit Planning for Energy-intensive Industry Microgrid Considering Economic Accommodation of Wind Power

Security and reliability of power supply are very important for the energy-intensive industry (EII) since insufficient power supply will cause great economic loss. Thus, the microgrid of EII usually has grid-connected structure to guarantee the power supply quality. However, the transfer power between the EII microgrid and the main grid must be limited in an interval, which is called as the power transfer limit (PTL). On the one hand, the EII must pay for the PTL (capacity cost); on the other hand, the operation cost of EII's microgrid is closely related to the PTL. Therefore, the optimal PTL needs to be determined to minimize the total cost (capacity cost and operation cost). In this paper, a bi-level PTL planning method is established in an EII microgrid with wind power and uncertain load. The optimal operation cost is obtained at the low level for the trial planning decision and the planning decision is updated at the high level to reduce the total cost. What's more, the robustness and nonanticipativity are guaranteed in the low level. Numerical testing is performed for a real system and the results show that the method is effective.