Electro-Thermal Simulation Analysis of $\pm 500 \text{kV}$ HVDC Submarine Cable Under External Steady-State Loads

The rapid development of offshore wind power projects has driven HVDC submarine cables toward higher capacity, elevated voltage levels, and extended transmission distances. Ensuring the safe operation of these cables in harsh marine environments has become an urgent challenge. This study addresses abnormal bending phenomena in <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\pm 500 \text{kV}$</tex> HVDC cables caused by external loads such as anchor hooks, ocean currents, and fishing net drag. A finite element simulation approach was employed to simplify the radial structure of the cable while minimizing modeling errors. Simulations were conducted to investigate the variation trends of electric and thermal fields under load-induced bending conditions. Results demonstrate that excessive bending displacement (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$&gt;1.2 \mathrm{m}$</tex>) and critical curvature (bending radius <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$&lt;500 \text{mm}$</tex>) induce distortion and fluctuations in the cable's multi-physical fields. Localized overheating and electric field concentration were observed under such conditions, which may compromise the safety of the entire cable system during prolonged operation.