Steady‐State Thermal Circuit Model and Verification of Multicircuit High‐Voltage Cables Based on Indirect Coupling of Wall Temperature

The working temperature of a cable is a key parameter for its current ampacity (load ampacity), and studying its performance is of great significance. This article aims to establish a steady‐state thermal circuit model for multicircuit high‐voltage cables. From the perspective of heat transfer, a heat transfer coupling method for multicircuit cables is proposed, and a steady‐state thermal circuit model for multicircuit high‐voltage cables considering current unbalance is constructed. First, by analyzing the heat transfer process of multicircuit high‐voltage cables, a model indirectly coupled with walls is proposed to achieve rapid calculation of temperature distribution and current ampacity of trefoil arranged cables. Second, a method of independent modeling of each subcable is adopted to further improve the model functions, including temperature distribution calculation when the current distribution is uneven and calculation of cable temperature at different positions. Finally, the effectiveness of the model in calculating current ampacity and temperature distribution is demonstrated by building a 500 kV parallel cable experimental platform.