Analysis of rated current-carrying capacity and temperature field of three-circuit 10kV cables under different laying methods

Abstract

To investigate the influence of laying methods on the rated current-carrying capacity and temperature field distribution of 10 kV three-circuit cables, this study takes the YJV22-8.7/15-3×240 three-core cable as the research object. Combining analytical methods with COMSOL finite element simulation, the thermal characteristics under three typical laying conditions—direct burial, pipe bank (duct), and cable trench—are analyzed. The current-carrying capacity is calculated using the analytical method, while a simulation model is constructed to simulate the heat transfer process, verify the capacity calculations, and analyze the temperature field distribution. Results show that the cable trench laying yields the highest current-carrying capacity, followed by direct burial, with pipe bank laying the lowest; the relative error between theoretical and simulation results does not exceed 3%. In all laying methods, the central circuit cable exhibits the highest temperature. The dominant influencing factors on current-carrying capacity are heat dissipation mode, medium thermal resistance, and inter-circuit spacing. This study provides scientific basis and technical support for refined design of multicircuit cable channels, dynamic assessment of current-carrying capacity, and safe and stable operation of power grids.