Coupled thermal modelling for dynamic submarine power cable in varying sea temperatures

To date, thermal loads have become one of the primary focuses of submarine power cable design. Though the thermal loads are a primary concern for buried cables, they have not been explored in detail for dynamic cables. This paper investigates the thermal loading of dynamic subsea power cables under different environmental conditions. The aim is to assess whether the thermal rating of dynamic cables can be adjusted based on the temperature of the surrounding water. This would enable a higher current rating in cooler climates, whilst the current rating in warmer conditions would be further constrained. Thermal modelling is undertaken using the Multiphysics FEA software COMSOL. This study models the thermal profile for a typical 66 kV copper conductor cable with a rated current of 903 A. The thermal boundary conditions are varied to represent different sea temperatures ranging between 5°C and 25°C. This range encompasses the sea temperatures associated with planned floating wind sites globally. The results show that the rated current of submarine power cable is reduced when the surrounding temperature increases. The cable could lose its rated current up to 112 A when sea temperature changes from 5°C to 25°C. Additionally, the ensemble of models also helps establish the relationship between sea temperature and steady-state cable core temperature. This paper provides valuable insights for researchers and engineers, supporting the thermal design of dynamic power cables and offering potential implications for the operational thermal rating of future floating wind farms.<p></p>