Multi-physics analysis and maximum temperature prediction for high-voltage cable tunnels

To investigate the maximum temperature of high-voltage cable tunnels, an electromagnetic–thermal–fluid multi-physics model is developed based on a practical 220 kV cable tunnel. The model integrates conductor loss, aluminum sheath eddy current loss, and airflow and is applied to the concrete tunnel to analyze the magnetic field, loss distribution, and coupled temperature field. The simulation results are validated against on-site measurements, including cable surface temperature distributions. This study is then extended to a prefabricated ductile iron tunnel to examine the effects of relative permeability and electrical conductivity on the induced loss and thermal behavior. The results provide guidance for the thermal design and engineering application of high-voltage cable tunnels.