Collaborative Optimal Configuration of UPFC and Energy Storage Based on Grid-connected Offshore Wind Power Clusters

With the proposal of "carbon neutralization and carbon peaking", along with the accesss of the large-scale, high-capacity, strong randomness, clean and low-carbon offshore wind farms to the grid, the power transmission network faces challenges such as uneven power flow distribution, section transmission capacity bottlenecks and other issues due to the lack of power flow control means, resulting in serious wind curtailment. The unified power flow controller (UPFC) can actively regulate the power flow distribution to solve the bottleneck issue of section transmission capacity, while the energy storage device can improve the flexibility of the power grid and stimulate new energy consumption. In view of a series of challenges brought by offshore wind power cluster grid connection, a collaborative optimization configuration method of UPFC and energy storage based on offshore wind power cluster grid connection is proposed. It takes the location and capacity of UPFC and energy storage devices as decision variables at the same time, and considers the uncertainty and time correlation of offshore wind power output. As a result, a distributionally robust collaborative optimization configuration method of UPFC and energy storage distribution is proposed. The original mixed integer non convex nonlinear programming model is then converted into a mixed integer second-order cone programming model by using second-order cone convex relaxation, large M method and other techniques to achieve efficient solution. Finally, the proposed model and method are validated through a case study of a 209-bus offshore wind power transmission system.