Research And Application Of Lightning ProtectionTechnology For Transmission Lines Of Ji Nan PowerGrid

Overhead transmission lines have many characteristics,such as many points,long lines and wide areas,and their natural environment is often complicated.Lightning strikes in Jinan have become the second largest factor causing transmission line trips.Lightning strikes on transmission lines are usually caused by lightning strikes or wires.Common lightning protection measures include reducing tower grounding resistance,reducing grounding protection angle,installing parallel gaps,erecting coupling grounding lines,installing line lightning arresters,strengthening line insulation,and installing tower lightning rods.Different lightning protection methods have different methods.Advantages and disadvantages,the applicable lightning protection type is also different.According to the importance of the transmission line,the natural environment,the type of tower,the insulation configuration,and the operating experience,it is often possible to achieve a multiplier effect by adopting a differentiated lightning protection strategy to carry out lightning protection.Based on the principle of lightning strikes on transmission lines and various lightning protection measures,this thesis introduces the concept of differential lightning protection for transmission lines,and puts forward the work focus of differentiated lightning protection for transmission lines.The technical principles have established a differentiated lightning protection assessment and governance process for transmission lines.Based on the current situation of lightning strikes on the transmission lines of Jinan Power Grid,this thesis deeply analyzes the typical faults of lightning strikes in the past,and comprehensively evaluates the lightning resistance level of the typical line of220kV ShichangI line,using the concept of differentiated lightning protection in 2016.In May,the 220kV ShichangI line was rebuilt.After calculation,220kV ShichangI line’s average counterattack lightning strike rate was 0.13693 times/(100 km·year),which was 18.05%lower than before the implementation;the average line lightning strike rate was 0.17943 times/(100 km·year).Compared with the pre-implementation,the reduction was 21.38%;the average comprehensive lightning strike rate was 0.31636 times/(100 km·year),which was 19.96%lower than that before the implementation.After the renovation of220kV Shichangl line,there was no lightning strike accident in the thunderstorm season of 2016 and 2017,and the lightning protection work achieved good engineering results.In this thesis,the engineering practice of differential lightning protection for transmission lines has a strong guiding significance for lightning protection transformation of transmission lines of voltage grades in other regions,and provides processes,techniques and measures for lightning protection transformation of transmission lines of voltage grades in other regions.The reference has strong promotion and practical application...