Optimal Planning for Electrical Collector System of Offshore Wind Farm with Double-sided Ring Topology

TL;DR

This paper introduces a novel optimization method for designing offshore wind farm electrical systems with a double-sided ring topology, improving cost efficiency and reliability while meeting fault tolerance standards.

Contribution

It develops a mixed-integer quadratic programming model based on CVRP for optimal cable layout considering power losses and fault tolerance, with constraints to avoid cable crossing.

Findings

Total cost reduced by up to 25.9% with reliability improvements.

Cable investment decreased by 4-8% compared to heuristic methods.

Method achieves good optimality and computational efficiency for large-scale OWFs.

Abstract

We propose a planning method for offshore wind farm electrical collector system (OWF-ECS) with double-sided ring topology meeting the "N-1" criterion on cable faults, in which the submarine cables layout of OWF is optimized considering cable length and power losses. The proposed mixed-integer quadratic programming (MIQP) model is based on the Capacitated Vehicle Routing Problem (CVRP) formulation and power network expansion planning, which could approximate the power losses in OWF-ECS. In addition, cross-avoidance constraints are proposed to avoid crossing cables, and the minimum k-degree center tree model is included to improve the convergence. Case studies on OWFs with 30 and 62 WTs demonstrate the effectiveness of the proposed method. Considering the potential outage cost in the radial topology, the total cost of the planning result is reduced by up to 25.9% with reliability improvement. The cable investment is reduced by 4%~8% with the proposed method compared with conventional heuristic methods and Google OR-tools. The proposed method/model can also achieve acceptable computation efficiency and OWF-ECS planning results with good optimality. Moreover, it could be solved by modern commercial solvers/optimization software, thus it's easy to use even for large-scale OWF.