The Research On Lightning Protection Technology Of 1000kV UHV AC Transmission Line

This paper studies the lightning performance of the transmission line by calculating and analyzing the lightning shielding failure and back flashover separately,based on the actual 1000 kV UHV AC line parameters.For the lightning shielding failure of the line,this paper studies the model of lightning shielding failure,analyzes the calculation method of the shielding failure trip-out rate considering the multi-factor condition in detail,and writes the shielding failure calculation software based on the MATLAB GUI.Based on the actual 1000 kV transmission line,the shielding failure trip-out rate is calculated in detail,and many factors influencing the shielding failure trip-out rate are analyzed.According to the influencing factors,the technical method to improve the performance of the lightning shielding protection is put forward.For the lightning back flashover of the line,this paper studies the tower model of lightning back flashover,analyzes the research method of the back flashover trip-out rate in detail,and analyzes the lightning protection level for back flashover by electromagnetic transient simulation program.The modules of transmission line are modeled by ATP-EMTP program,to build the lightning back flashover model.The lightning protection level for back flashover of 1000 kV line can be obtained by simulation,and the back flashover trip-out rate can be calculated.This paper also studies the influence of different factors on the lightning protection level for back flashover,and finds out the technical measures to improve the level of lightning protection according to the factors,to enhances the lightning protection performance for back flashover of the transmission line.In addition,this paper also studies the influence of natural condition factors on lightning trip-out rate.The simulation mainly analysis that the lightning current waveforms of different half–crests time and the haze meteorological conditions make the error of the line lightning protection level,and obtains the intuitive results.Finally,based on the influence factors of lightning shielding failure and back flashover,this paper summarizes a number of technical measures to improve the performance of UHV lightning protection,to provide comprehensive protection for transmission line lightning protection.