Simulation analysis of synthetic electric field of UHV transmission line under mountain fire condition

Abstract

Factors such as high temperature, charge density and charged particles have a major impact on the insulation strength of the transmission line gap. When the DC transmission line is in normal operation, the surface of the conductor is easy to adsorb dirt due to the environmental influences, so the local electric field strength is larger than the critical field strength of the corona discharge, and the gas molecules in the air are ionized to form space charges. The electric field of the space charge is superimposed with the electric field of the wire and the earth (nominal electric field) to form a synthetic electric field. In this work, the calculation model of the synthetic electric field is created and the influence of mountain fires on the synthetic electric field of the transmission line is simulated and analyzed. The influence of flame temperature, charge density, particle type and shape on the electric field is simulated and investigated. The law of variation of the electric field of the transmission line in mountain fire under different factors is obtained. The distorting effect of particles on the electric field under the UHV DC transmission line is simulated. The distorting effect of particle size and particle chain on the synthetic electric field is obtained and the simulation results are compared to the calculation results.