Analysis of Ice-shedding induced flashover accident on a transmission line in mountainous terrain

Abstract

Transmission lines are essential infrastructure for modern society. Large amplitude vibration of conductors due to ice shedding may cause electrical faults, resulting from insufficient clearance among different phases and phase conductors and ground wires. A flashover fault on a 500kV transmission line located in a mountainous area, which is caused by ice shedding, is analysed in this paper. The approximate reason and history of the flashover accident were restored by the nonlinear finite element method with the help of ANSYS software. The key physical parameters such as conductor ice thickness and amount of ice shedding at the moment of the accident were analysed. The study in this paper helps to gain a deeper understanding of the ice-shedding–induced disasters of transmission lines and provides important reference for the design of transmission structures.

Study on the Bouncing Process Induced by Ice Shedding on Overhead Conductors under Strong Wind Conditions

“…Because of sunshine, temperature, airflow, load current and other factors, icing can be shed from overhead lines in large chunks, resulting in large oscillations in conductors, known as ice shedding. Ice shedding on overhead conductors is a low-frequency, large-amplitude vibration phenomenon that can cause transmission line destruction, conductor strand breakage, conductor interphase flashovers, damage to metal fixtures, pendant insulator clamp slippage, spacer bar fractures, transmission tower crossbar distortions, and loosening of tower bolts [3,4]. In serious cases, it can cause conductor fracture and tower collapse, resulting in wide-scale power supply interruptions, jeopardizing the stability and continuous operation of a power grid [5,6].…”