  A set of solver-free heuristics for the offshore wind collection system
problem are presented. Currently, methods of this type are not able to cope
with typical constraints, and most of their variations minimize only for
accumulated cable length. The first algorithm is a two-steps decision process,
where the output is the design of a tree network satisfying cable thermal
limits constraints, but vulnerable to violate planarity constraints.
Subsequently, a cable crossings repair heuristic is introduced in order to fix
infeasible points from the first heuristic. Finally, a refining heuristic
(negative cycle cancelling refining heuristic) takes over to improve feasible
points. The latter iteratively swaps cables, intending to find cycles with
negative costs that will lead to investment savings. The sequence of heuristics
supports the most important restrictions of the problem. The applicability of
the workflow is empirically demonstrated by means of a set of large-scale
real-world offshore wind farms. The numerical results indicate that: (i)
feasible points can be retrieved in computing times in order of seconds, and
(ii) warm-starting can help solvers to converge significantly faster for
problems with solution time in order of several hours.
