A multi-stage methodology for wind park inter-array cabling: graph preparation, layout, and sizing

Abstract. Inter-array grid optimisation plays a critical role in the technical and economic performance of wind parks and is typically divided into two primary tasks: layout length minimisation and conductor size selection. This work proposes the consideration of three primary tasks, beginning with graph preparation to account for terrain profiles, soft and hard exclusion zones, and export cables. Once a graph with viable connection pathways is established, a pathfinding mixed-integer linear formulation for radial arrays, subject to crossing constraints and a maximum number of turbines per string, is presented. This formulation can be adapted to user requirements to include a minimum number of turbines per string, as well as a methodology to determine the minimum number of substation connections required under irregular turbine distributions arising from terrain constraints. Conductor size selection is addressed through a linear approximation of the power flow, enabling the limitation of the number of conductor types used within the system. Pathfinding and conductor size selection may be combined within an integrated approach or implemented as a sequential algorithm to explore trade-offs between trenching and cabling costs. The proposed approaches are evaluated using current turbine ratings and the layouts of both onshore and offshore existing projects.