Research On Lightning Model And Application Of 35kV Overhead Transmission Line

35kV overhead transmission line plays a very important role in the distribution network of our country,which is also the important distribution network in China.Since 35 kV is a medium voltage level,it directly allocates and transfers power to the majority of users.Generally no lightning protection and the low line insulation level,the lightning protection performance is poor and the safe operation is directly threatened by lightning.Lightning is one of the important reasons that leading to the 35 kV distribution line fault.Therefore,in view of the characteristics of 35 kV distribution lines,it is very important to find relatively perfect lightning protection measures to ensure the safe and stable operation of the distribution network.Evaluation of the line lightning protection performance are mainly the lightning trip out rate and the lightning protection level.According to the regulations,the calculation of lightning trip probability is very low,while the EGM has higher accuracy.Based on the EGM model and the concept of striking distance,this paper draws a conclusion that the calculation of trip rate is more accurate with the exposure distance,combining the characteristics of lines from Wolong station to Tianshengqiao.In addition,this paper also analyzes the factors that affect the tripping rate,the ground tilt angle and the angle of protection.In this paper,the lightning protection performance of the 35 kV overhead transmission line in Wolong station is studied as an example.Firstly,this paper introduces the existing lightning protection measures and methods from the 35 kV power network,and points out some problems existing in the existing lightning protection measures.According to the characteristics of the lightning protection of the line,the calculation and analysis of the circuit are carried out by using the method of regulation and the method of the electrical geometric model,and the results of the two methods are compared and analyzed to obtain higher accuracy.Secondly,based on the PSCAD/EMTDC,the lightning over-voltage model was built,including lightning current arrester tower model and 35 kV model of overhead line insulators.The comprehensive lightning protection simulation is carried out to study the influence of grounding resistance and lightning arrester on lightning protection that can improve the lightning protection performance of the line by reducing the groundingresistance and installing the line arrester.In addition,considering the economic transformation of the line,The effect of lightning protection tower in the different arrester configuration and the technical and economic was analyzed and put forward the line arrester configuration scheme of technical and economic indicators.Combined with the actual project,verify the simulation results.In conclusion,this paper summarizes the research and prospects for the study of 35 kV overhead transmission line lightning protection measures,which provides the reference in the future.