Technical Benchmarking of Site Acceptance Testing Methods of Offshore Wind Farm HVAC Power Cables

The reliability of an offshore wind farm (OWF) depends strongly on the export and inter-array cable installations. AC export cables (EXCs) are typically up to 120 km long and operate at voltages ranging from 220 to 275 kV. The newest inter-array cables (IACs) operate at 66 kV and can be up to 20 km long. They connect individual wind turbines to the offshore substation. This paper discusses current failure statistics and costs, as well as the technical challenges associated with different site acceptance testing (SAT) methods for offshore wind farm export and inter-array cables. The technical benchmark analysis for both EXCs and IACs shows the most reliable solutions for SAT. Moreover, practical applications based on 13 international OWF installations show that damped AC (DAC) supports quality control of newly installed EXC and IAC cable systems and provides a solid basis for in-service condition-based maintenance.