THERMAL ANALYSIS OF XLPE INSULATED SUBMARINE CABLES FOR DIFFERENT LOADING CONDITIONS

Submarine cables are critical assets that play an indispensable role in interconnected power systems, particularly in cross-sea energy transmission and offshore wind turbines. Their importance is further accentuated in exigent situations such as natural disasters and war, which emphasize the need for secure, reliable and uninterrupted energy supply. Furthermore, the investment and operating costs of submarine cables are relatively higher than other power system equipment, making it essential to operate them under the rated operating conditions to prevent possible faults and ensure power system stability. As thermal stress can lead to damage of cable insulation, it is an essential parameter to consider. Overloading increases thermal stress, resulting in rapid aging of the cable insulation and a shorter cable lifetime. Therefore, it is imperative to determine the maximum conductor temperatures and current carrying capacities of submarine cables under varying loading rates and ambient conditions using thermal analysis. In this study, thermal analyses are carried out for a three-phase, 220 kV HVAC, XLPE insulated submarine cable under different loading conditions. The findings demonstrate that the maximum temperature, current carrying capacity, and total losses of the cable are significantly impacted by loading rate, phase imbalance, and seawater temperature.