Numerical modeling and analysis of thermal and mechanical behavior for ground wire-clamp system under short-circuit current

Abstract

In the ground wire-clamp system, aluminum armor tape (AAT) or armor rod (AR) is commonly adopted to avoid the wear damage of ground wire. While under the short-circuit current, damage or even breakage of ground wire in suspension clamp due to overheat may occur. However, there still lacks attention on the investigation about this type of damage. In this paper, a finite element (FE) modeling method of the ground wire-clamp system, which was applicable to two cases with AAT and AR, was proposed to discuss the transient thermal and mechanical behaviors. In the modeling of contact points, an improved contact bridge model considering the contact shape characteristics was proposed. The transient temperature rise experiments for ground wire-clamp systems with AAT and AR were carried out to verify the accuracy of models. The results shows that the improved contact bridge model is conducive to obtaining the accurate calculation results. For the analysis of this type of damage, the generated thermal stress cannot be ignored. In engineering, the ground wire twinned by AAT is at risk of overheat or even breakage under the short-circuit current, while using AR can prevent the ground wire in the suspension clamp from damage of overheat.