Characteristics of Water Tree in Submarine Cables for Offshore Wind Power

This technical report discusses the characteristics of water tree degradation in submarine cables designed for offshore wind power generation. It outlines the challenges faced by submarine cables, particularly those lacking an impermeable structure, which are prone to water tree deterioration. The report presents a long-term testing method aimed at simulating 30 years of operational conditions to evaluate the service life of these cables. It details the growth mechanisms of water trees, emphasizing the importance of moisture content in the insulator and the correlation with cable degradation. The study also describes various submerged voltage endurance tests conducted to assess the water-tree resistance of prototype cables. It highlights the significance of supersaturated moisture in the growth of water trees and the need for a reliable testing framework to predict the long-term performance of non-impermeable submarine cables in actual transmission lines. The findings aim to contribute to the development of more resilient submarine cables for future offshore wind power applications.