Offshore wind farm cable layouts optimization considering offshore substation placement

The rising investment, particularly in electrical systems as offshore wind farms (OWFs) grow in size and distance from shore, has driven attention to optimizing these systems to reduce the levelized cost of energy (LCoE). Offshore wind farm cable systems alone can account for up to 9 % of total project costs, making efficient cable connection layout a crucial factor in minimizing expenses. Therefore, this study presents a Mixed Integer Linear Programming (MILP) model that optimizes the offshore substation (OS) location, cable connection layout, and cable sectional area selection simultaneously. This model streamlines the original mixed integer second-order cone programming (MISOCP) problem by means of a piecewise linear approximation and relaxation, significantly boosting computational efficiency while incurring only a limited gap from the global optimal solution. Additionally, we propose a pre-processing method that breaks the problem into two sub-problems, demonstrating its equivalence to the original formulation. This approach offers a comprehensive solution for reducing the overall cost of OWF electrical systems. And it achieves a desirable balance of high precision and fast convergence, making it an efficient approach for obtaining sub-optimal solutions within practical computation time.