Evaluation of the Eletrical and Mechanical Properties of the Insulation in Wet design Submarine Cables

This study evaluated the electrical and mechanical properties of wet design submarine cable insulation materials to improve long term reliability in offshore wind applications. XLPE, TR XLPE A, and TR XLPE B were evaluated through volume resistivity and AC dielectric breakdown measurements using 0.2mm thin specimens and accelerated aging specimens produced under ASTM D6097. TR XLPE B showed about 5.9 times higher volume resistivity than XLPE, and both TR XLPE types exhibited roughly a 2% increase in AC dielectric breakdown, with accelerated aging specimens showing an additional 5.4% improvement. Mechanical tests confirmed that XLPE had the highest tensile strength and elongation. These results provide baseline criteria for evaluating insulation degradation under frequency accelerated aging and serve as important evaluation guidelines when manufacturing factory joints, ultimately contributing to the long-term reliability of submarine power cables.