Application And Evaluation Of Differentiated Lightning Protection For Transmission Lines In Shandong

Operating experience shows that lightning is the main reason for the trip-out fault of transmission lines.As a result of the unique geographical environment,lightning activity is very common in Shandong Province,from 2011 to 2014,Shandong province electric power company under the jurisdiction of 500kV lightning trip rate were 0.057,0.036,0.109,0.018 and 0 and 0.013 km/100-year.,caused serious impact on the effective operation of the power grid.Statistics of the lightning fault in Shandong power grid over the years were collected,and also the differences of lightning fault among the different types and different terrain were analyzed in this paper.The relationship between the lightning trip-out and tower type,tower height and flashover phase of different transmission lines,especially for the 500kV and 220kV transmission line was obtained through the statistical analysis.The statistics and analysis of the observation data about lightning parameters in different time and different area of Shandong province was conducted according to the lightning location system from 2008 to 2011,obtaining the temporal and spatial distribution information of lightning activity and the lightning risk distribution with different voltage classes in Shandong.The differentiated lightning protection strategy for transmission line,which can be summed up in four words:selective,focused,targeted and differential,was proposed by the analysis of trip-out rate and lightning activity difference,and then the detailed lightning parameters for the practical line was presented by taking 500kV Jichang Ⅱ line as the research object.Moreover,through the comprehensive consideration and analysis on the insulation characteristics and geomorphic features of the line terrain and the calculation of lightning protection parameters for transmission tower one by one,the lightning trip-out rate of transmission line for each tower was obtained.Based on the analysis of economy and operability,a reform scheme of lightning protection measures was proposed in this paper,and the expected lightning trip-out rate can be declined by 21.92%.