Bi-Level Planning of Transmission Systems for Partitioned Offshore Wind Power Bases

The development of offshore wind power bases in deep-sea areas has become a new trend. However, the limited accommodation capacity of onshore regional grids and equipment capacity constraints pose significant challenges for large-scale offshore wind power integration. This paper proposes a bi-level planning method for the transmission systems of partitioned offshore wind power bases. First, a density peak clustering algorithm is applied to partition offshore wind power bases while accounting for onshore grid capacity constraints. A bi-level optimization model is then established. The upper-level model optimizes the siting and sizing of medium-voltage substations and offshore converter stations, while the lower-level model focuses on the planning of VSC-HVDC transmission systems. By iteratively updates, the optimal transmission scheme for partitioned offshore wind power bases is obtained. Case studies based on an actual large offshore wind power base demonstrate that the proposed method significantly reduces planning costs and improves computational efficiency.