The Study Of Differential Lightning Protection Of 500kV Transmission Lines Of Southern Hebei Network

Lightning as the worst natural disasters for transmission lines,it caused that the lightning trip-out rate always keep very high.Now 500 k V become backbone transmission line voltage grade,and the increasing of voltage grade will make lightning trip-out rate rise.Lightning tripping accidents not only has direct relationship with the voltage level,and closely relate with the transmission lines of landform,lightning activity,structural parameters of transmission lines and transmission line insulation strength factors. The purpose of the differential transmission line lightning protection evaluation study is that we can combine all of the influence of various factors to evaluate transmission lines,and then we can achieve the purpose of reducing lightning trip-out rate.In this paper I do the study of differential lightning protection of 500 k V transmission lines of south power grid,Hebei province. First of all,we analysis lightning activity in recent years,according to the lightning location system of 500 k V transmission line in Southern He Bei Network. Combining with the lightning accident situation in recent years to analyze the feasibility and necessity of the differentiation of 500 k V transmission lines lightning protection in Southern He Bei Network. After that I do some study about the computing methods of transmission lines lightning of500 k V transmission lines in Southern He Bei Network.And then we can make certain guidance on the differentiation lightning protection work. Finally building lightning protection assessment system combine lightning parameter statistics,Parameter information management,line lightning protection simulation calculation,transmission line lightning flashover risk assessment,comprehensive control of transmission line analysis.In order to realize targeted line lightning protection evaluation pattern of “single infrastructure mode-single base assessment-single base governance” and complete each base tower qualitative quantitative tripping rate and threat level assessment and realize differentiating lightning protection measures of intelligent selection and specific construction plan formulation function,I build the simulation model on the basis of full information parameter database.