Influence of Soil Thermal Resistivity on Underground Cable Temperature in Tunnel for Dynamic Cable Rating Study

The reliability of underground power cables is significantly influenced by soil thermal resistivity. Variations in soil moisture content significantly affect thermal resistivity, influencing heat dissipation and cable temperature. This paper investigates the effects of different soil thermal resistivity values (0.7, 1.0, 1.2, and 2.0 °C.mJW) on underground cable temperature inside a tunnel in Malaysia as part of a dynamic cable rating (DCR) study. The study aims to analyze how soil thermal resistivity can directly or indirectly influence the thermal performance of power cables installed in tunnel environments. Numerical simulations are performed using CYMCAP, a specialized software for power cable ampacity analysis, to evaluate the impact of varying soil thermal conditions on cable temperature. The results indicate that higher soil thermal resistivity significantly increases cable temperatures, which can reduce the allowable ampacity of underground cables. These findings provide valuable insights for engineers and utility planners in optimizing underground cable installations by considering soil thermal properties. Understanding the thermal behavior of cables in different soil conditions is crucial for improving the reliability, efficiency, and overall performance of underground power transmission systems.