Calculation study regarding hot gases rising due to arcs and arc jets generated between arcing horns on 66 kV overhead transmission lines

Abstract

Lightning to an overhead transmission line system can cause a breakdown between arcing horns of the lower line and a jumper wire of the upper line due to the rising of hot gases generated by arc jets between arcing horns. This article describes the experiments and the calculations regarding the rising of the hot gases for the case of 66 kV overhead transmission lines. The calculations were carried out considering the length of the arc jet, the electromagnetic force acting between the arc jet and the arc column, the force due to the arc jet spouting from the arcing horn, and the buoyant force of the hot gases for various arc currents and two types of arcing horn. As a result, it was found that the calculation results showed a tendency similar to the experimental ones. Furthermore, the breakdown phenomena between the arcing horns and the jumper wire were also investigated using the calculation results. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.