Comprehensive Analysis of Thermal Rating Methods for Buried Power Cables: Modeling Approaches and Transient Behavior

This paper provides a comprehensive analysis of thermal rating methods for buried power cables. Transient analysis of cable is performed, incorporating environmental conditions, soil thermal properties, cable temperatures, and loading conditions. The study highlights the critical influence of factors such as soil thermal resistivity, burial depth, and ambient temperature on cable ampacity ratings. Thermal-electrical equivalent and IEC60853 two loop network, are presented to capture the transient thermal response of cable components and surrounding soil. Comparative studies between IEC 60853–2 and a thermal-electrical equivalent model illustrate the importance of accounting for soil thermal capacitance. Furthermore, a detailed case study investigates the permissible overload durations for buried cables under varying initial loading conditions and overload percentages. The findings underscore the significance of considering loading history for determining safe cable overload capabilities, facilitating informed decision-making by utilities for optimized power transmission reliability and asset utilization.