Finite Element Analysis of Hotspot in Contact Fracture between Ground Wire and Performed Armor Rods based on Skin Effect and Contact Resistance

It is a major problem that ground wire breakage occurs due to the high temperature rise. And it is of great significance to study temperature rise characteristics of its hotspot. A 3-D finite element model of contact fracture between the ground wire and preformed armor rod is set up in the paper and firstly the equivalent method of contact resistance is analyzed and determined. Based on this model, influence of skin effect on contact resistance of contact fracture area is studied. Furthermore, effect of contact resistance and short circuit current on transient temperature rise in the contact fracture area are also analyzed. It can be concluded that the deeper the degree of skin effect, the greater the contact resistance and temperature rise. And with the combined effect of contact resistance and short circuit current, the possibility of direct fusing of the ground wire is proved. Moreover, temperature rise ratio of the ground wire which is away from contact fracture is much less than that of contact fracture area.