Electro-Thermal-Fluid Coupling Analysis of Ultra-High Voltage Cable Tunnel

According to the cable tunnel structure and internal layout, a three-dimensional geometric model is established by COMSOL Multiphysics. The electro-thermal-fluid coupling simulation is performed using the finite element method (FEM) to analyze the temperature distribution of tunnel. The ampacity is determined, considering the current load, the number of operating circuits and the ventilation rate. The thermal and fluid fields are investigated under different operating and environmental conditions. The results indicate that the maximum temperature is occurred at the cable conductor, with a gradual decrease along the radial direction of cable. The temperature and wind speed at the outlet is higher than that of inlet section. The cable ampacity can be influenced by the number of loops. With the rise of current, the impact of cable heating on ambient temperature is increased.