Balanced cable routing for offshore wind farms with obstacles

Abstract

The cable routing problem is the task of designing the minimum-cost electrical network between the turbines of offshore wind farms while satisfying several constraints. It contributes to decreasing wind energy costs, favoring the green transition. This paper focuses on balanced cable routing, studying both branched and radial network topology. First, we propose a visibility graph to route cables around obstacles and boundaries present in the wind farm area. Next, we develop a novel Large Neighborhood Search (LNS) heuristic using neighborhoods of increasing complexity: swap, exchanging two turbines between root-branches; double swap, exchanging two pairs of turbines; cycle swap, moving turbines between root-branches; and re-partition, re-partitioning and re-routing two adjacent root-branches. We also extend the LNS heuristic to the unbalanced branched configuration to compare to existing literature. On average, it finds solutions of the same quality using two orders of magnitude less run-time, improving the solutions in five cases.

Offshore Electrical Grid Layout Optimization for Floating Wind—A Review

“…It connects turbines in a string with at most only one cable entering and one cabling exiting each turbine. It is important to note that as a subset of the branched topology, the radial connection cannot deliver shorter cable paths but can ease the computational effort since it considers engineering constraints from the beginning [9]. In commercial-scale OWFs, the radial connection scheme is widely used at present since it is a relatively simple layout and offers a high degree of flexibility in control while simultaneously coming with low initial investment cost.…”

“…This graph contains all connections from the starting point (OSS) to all straight-lined accessible clients (WTs), the corners of the exclusion zones, and their edges. For reasons of clarity, a visibility graph is included in Figure 11 from [9], where this problem is also tackled accordingly.…”

“…Based on the experience described above, the same authors focused on the neighborhood search metaheuristic in a later work [9]. They note that the branched topology problem has only been studied in an unbalanced case, meaning that an arbitrary number of WTs could be allocated to a string, resulting in strings carrying different amounts of electrical charges.…”

Spatial Optimization for Energy Island Location and Cable Routing Considering Offshore Zoning

“…Numerous studies have concentrated on spatial optimization, typically addressing specific facets of the problem rather than approaching the optimization holistically. Meanwhile, a considerable number of studies have focused on the routing optimization within the wind farm, such as [7], [8], [9], [10]. A recent study from Backstrom [11] and Warden focused on export cable routing using GIS environmental heat maps.…”

Wind farm array cable layout optimisation for complex offshore sites—A decomposition based heuristic approach

“…Additionally, the proposed layout solutions contained many branching connections at the Steiner nodes, which again is not a practical solution for real offshore cases [22]. Other heuristic methods have been shown to be computationally fast with one study utilising a large neighbourhood search algorithm, followed by swapping and re‐partitioning heuristics, claiming two orders of magnitude reduction in time‐to‐solutions [23]. GAs are promising heuristic methods, capable of handling large numbers of turbines to connect through the collector network, with one study considering 280 turbines [24].…”