Keywords
intermediate joint; explosion-proof box; contact resistance; insulation aging; finite element theory
Abstract
The three-core cable intermediate joint is a vulnerable component of the cable system. The addition of an explosion-proof box can effectively prevent joint failure from affecting the normal operation of other cables, and also affects the surface temperature distribution of the joint. In this paper, a three-dimensional full-scale model of a 35 kV cable intermediate joint with an explosion-proof box is developed, and a multiphysics coupled simulation model based on finite element theory is established. The influence of contact resistance on the temperature of the joint inside the explosion-proof box and the influence of the gel-filled explosion-proof box on the current-carrying capacity of the joint are studied. By simulating insulation aging and heating defect conditions, the surface temperature distribution characteristics of cable intermediate joints with explosion-proof boxes are obtained. The results show that, due to the thermal resistance effect, the conductor current-carrying capacity of the gel-filled explosion-proof box decreases by 12.77% compared with the bare joint condition, and insulation aging has little effect on the surface temperature rise. When a heating defect occurs at the splice tube, the presence of the gel-filled explosion-proof box causes the maximum temperature region on the joint surface to shift from the traditional end region to the outer surface corresponding to the splice tube. Single-phase and two-phase defects increase the temperature rise by 11.65 ℃ and 13.3 ℃, respectively. Heating defects of cable joints inside gel-filled explosion-proof boxes can be identified by monitoring the temperature rise amplitudes at six positions on the outer surface of the joint at the center of the splice tube. The results provide a theoretical basis for condition monitoring and reliability evaluation of cable intermediate joints and have reference value for optimizing condition-based maintenance procedures for smart grid equipment.
DOI
10.19781/j.issn.1673-9140.2026.01.028
First Page
298
Last Page
306
Recommended Citation
ZHANG, Dongdong; WAN, Huijuan; ZHANG, Yi; YU, Jicheng; YE, Tonghui; QIAO, Xinhan; JIAO, Ting; WANG, Yinshan; and WANG, Ruoxi
(2026)
"Temperature distribution characteristics and heat identification method of cable intermediate joints with explosion-proof boxes,"
Journal of Electric Power Science and Technology: Vol. 41:
Iss.
1, Article 28.
DOI: 10.19781/j.issn.1673-9140.2026.01.028
Available at:
https://jepst.researchcommons.org/journal/vol41/iss1/28
