A novel approach to estimate temperature of conductor in cable joint

摘要

The power cable has been widely used for decades. As an important accessory of power cable, the cable joint is the weak link because of site installation conditions. Partial discharge and insulation aging in it cause temperature rise, which may lead to explosion of the cable joint in serious conditions. There are many researches about temperature rise of the cable and cable joints. By measuring the surface temperature and conductor current, some scholars in Tokyo proposed a way to estimate conductor temperature in cable joint with a 2-D thermal circuit. A method to estimate soil thermal parameters and assess cable ratings is introduced, in which the location of hot spots, cable installation data, load and DTS-recorded temperature should be the given information. Considering the influence of moisture content on thermal resistivity and specific heat of the cable surroundings, an algorithm for the estimation of the time-dependent temperature evolution of power cables is presented. Just as partial discharge is an feature of defect in the cable joint, temperature rise can also reflect defect in it. So, the estimation of transient temperature is of great meaning. In this paper, the authors propose a novel approach to estimate transient temperature of conductor in cable joint for buried cables.