Study On Lightning Protection Measures Of The 10kV Power Grid In Zhanjiang

Zhanjiang is located in the coastal region of southwestern Chinese mainland,it belongs to Chinese traditional thunderstorm area.In summer thunderstorm season,10 kV overhead line tripping and equipment damage caused by lightning often occur,which affects the reliability of power supply.10 kV distribution network is divided into medium voltage in the voltage level,which is mainly composed of 10 kV distribution lines,transformers,circuit breakers and other facilities.It is responsible for transmitting the substation power and converting the power into what the need of social production and life.With the economic and social development of Zhanjiang,what measures can be taken to reduce the lightning damage of medium voltage lines in this area,so as to improve the stability of power supply,has practical research significance and application value.In this paper,the lightning protection measures of 10 kV distribution network in Zhanjiang area is taken as the research object,and the following works are carried out.(1)The climate and terrain of Zhanjiang and its thunderstorm area division are analyzed,the situation of 10 kV distribution network affected by lightning is studied,and the characteristics of 10 kV distribution network equipment vulnerable to lightning strike as well as the lightning protection defects existing in the actual equipment operation and maintenance are researched.(2)The calculation methods of induced overvoltage and direct lightning overvoltage on10 kV overhead distribution line are given,and the quantitative analysis of arc building rate is carried out.Combined with the actual situation,the improvement measures of lightning protection for 10 kV overhead lines are studied.The lightning withstand level of the line is calculated,and the lightning withstand level of the line under different installation modes of the arrester is studied by using ATP-EMTP simulation software,so as to provide the basis for the subsequent lightning protection transformation.(3)The lightning damage mechanism which leads to the power failure of 10 kV distribution transformer is analyzed,and the reasons are found out.According to the analysis results and the existing lightning protection problem of transformer,the improvement methods are proposed.(4)Other lightning protection short board problems existing in 10 kV distribution network in Zhanjiang area are analyzed,such as insulator damage,arrester breakdown,insulated wire disconnection,lightning protection of pole switch and excessive grounding resistance,etc.,and corresponding improvement measures are proposed.(5)Combined with the lightning protection effect of 10 kV distribution network in Zhanjiang area,it is proved that the research results of lightning protection measures in this paper are completely suitable for the lightning protection application in Zhanjiang thunderstorm area.