Offshore wind farm collector system layout optimization based on self-tracking minimum spanning tree

This paper presents a complete model of collector system layout optimization for offshore wind farms, which consists of both internal and external designs. The internal design uses the algorithm of self-tracking minimum spanning tree (ST-MST) combined with added functions of automatic cable selecting (ACS) and cable crossing avoiding (CCA) to form a radial topology. In addition, the features above are also integrated with the use of direct current transmission in the external design, which applies a self-designed searching method to find the optimal locations for VSC converters. The internal and external designs constitute the whole model of the offshore wind farm. More specifically, the internal connection begins with the Fuzzy C-means clustering method to divide the farm into clusters, where each center of the cluster locates a substation connecting to the turbines belonging to it. The external connection of the wind farm considers the use of high voltage direct current, which saves a great amount of reactive power in long distance transmission. Both the internal and external designs apply ST-MST with ACS and CCA, while the external connection is also given a higher priority as it uses the cables with larger cross sections compared with internal connection.