Cable Loading in Tunnels Based on Efficient Multi-physics Simulation Method

Electricity-heat-flow calculation supports cable loading design in tunnels. Analytical method based on IEC-60287 does not consider the corrugated sheath in detail. This paper proposes an efficient simulation approach for cables with corrugated sheath based on finite element method. The efficiency of the proposed mothed is 4 times as the original one, based on which a 200m tunnel with 24 high voltage cables is established to study the influence of wind velocity on temperature distribution. The cooling effect is more obvious with wind velocity lower than 3m/s. Maximum cable loading is also derived for different wind velocities. Furthermore, cable position and tunnel structure effect on the temperature are analyzed. Simulation results show that further away from the tunnel wall with 0.3m can reduce the temperature by about 3°C. While round shape tunnel leads to lower temperature than rectangular one with the same area.