This study investigates the insulation performance of a 66 kV dry-type submarine cable used in offshore wind farms under mechanical aging. During installation and operation, submarine cables are subjected to various mechanical stresses, including tension, compression, and bending, which can lead to insulation deterioration. In this study, XLPE samples extracted from a submarine cable were prepared and subjected to controlled tensile strain below the yield strain to evaluate their mechanical and electrical performance. Changes in tensile strength, elongation, and tan δ (dielectric loss factor) were measured to assess the extent of aging. The results indicate that as the applied strain and exposure duration increased, tensile strength and elongation decreased, while tan δ values increased, signifying a decline in electrical insulation performance. A strong negative correlation (R = -0.809) was observed between tan δ and tensile strength, demonstrating that mechanical aging significantly affects electrical properties. These findings highlight the importance of minimizing excessive mechanical stress during the installation and operation of submarine cables. The results provide valuable insights for enhancing the reliability of submarine cables in offshore wind farms and emphasize the necessity of optimized design and maintenance strategies to mitigate the effects of mechanical aging.
