Analysis of low frequency in offshore wind inner-array systems

Abstract

Since large-scale offshore wind farms have been installed, generators have been constantly improving all the systems that make up these wind farms in order to obtain the cheapest energy price. Numerous improvements have been implemented to achieve this goal over the last few years, leading to a reduction in the levelised cost of energy (LCoE). In all projects using alternating current in both the collector system and the transmission system, the industrial frequency of 50/60 Hz has been used.

Recent studies have evaluated the possibility of using a lower frequency than 50/60 Hz, so that low frequency transmission not only increases the power capacity to be transmitted by cables, but also reduces cable losses. In this article, a detailed study of the energy losses in the collector system of a wind farm has been carried out as a function of frequency. The study shows a reduction in losses as the frequency is reduced, although the variation is not excessively large.