Partial discharge characteristics of the 10 kV cable joint with mismatched cross-sections

Cable aging and insulation damage represent a significant threat to the safety of power transmission. The repair process for cables necessitates the use of crimping, yet the alteration of contact resistance at the crimp site may result in an elevated contact temperature when the cable is subjected to loading. Additionally, cable insulation defects and other underlying issues can contribute to this phenomenon. This paper presents a finite element simulation study of the temperature rise at the contact point of 10kV three-core cables with sections of 70, 120, and 300mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. The simulation results demonstrate a significant correlation between the degree of connection tightness at the contact point and the temperature rise. In this paper, an experimental platform is constructed by crimping the cable with cold-shrinkable intermediate joints. The experimental transformer is used to stimulate the cable, and the temperature monitoring is carried out for cables with different wire diameters. Meanwhile, the partial discharge at the cable joints is detected by the method of ultra-high frequency and the method of pulsed current, among others. The relevant characteristics of the partial discharge at the cable joints are obtained.