Collector System Topology for Large-Scale Offshore Wind Farms Considering Cross-Substation Incorporation

Double-sided ring topology has been widely applied in collector system planning for large-scale offshore wind farms (OWF), owing to its high reliability against cable faults. For collector systems with multiple substations, the conventional topology designs isolate the operation of substations, which requires high transformer capacity within each substation to satisfy the redundancy need. This paper first investigates the economic and reliability benefits of multi-substation incorporation (CSI), and then proposes a new double-sided ring topology with CSI for large-scale OWF collector systems. It encourages the transformer capacity sharing among multiple substations to improve the economic efficiency of collector system and in the meantime preserve the reliability advantage of ring topology. To achieve the optimal topology design, Fuzzy C-means (FCM) clustering method is adopted to locate substations and allocate turbines, and the Two-Phase Clark and Wright's saving algorithm is modified and applied to optimize the cable connection for the proposed topology so as to minimize the overall collector system cost. The proposed topology is tested and compared with traditional isolated topologies on two benchmark collector systems. The test results verify that the proposed the highest economic efficiency while maintaining the collector system reliability.