Transient discharge characteristics of insulator short-circuit under high voltage

The insulation failure is common in high voltage transmission. Based on experimental structure, this paper adopts the finite element method to establish the mathematical model of the short-circuit insulator discharge. Simplify the insulator discharge into a short circuit process between the upper and lower plates, and explore the process of generation, adsorption and neutralization of electrons, positive ions and negative ions, studied how the space charge variation affects the electric field intensity, and analyzed the distribution of each type of ionization products from the wires during the discharge. The results show that: when the insulator is short-circuited and discharged, the area with larger electric field strength is mainly concentrated near the upper plate; the electric field intensity in the discharge space tended to stabilize at the completion of the discharge; when the short-circuit wires were fused, the electron concentration remained stable for a short while at certain positions of the discharge space; as the discharge continued, the electron concentration at these positions declined rapidly; the electrons moved to the plates, causing fluctuations in electric field intensity; the variation of electron concentration during the discharge obeyed the Gaussian distribution. The research results provide the experimental evidence and theoretical reference for avoiding transient discharge in equipment operation. (C) 2021 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University.