Analysis of Lightning-strike Fault of Distribution Transformer and Study on Lightning Protection Measures

Lightning strike is one of the important factors which causes the 10 kV distribution lines faults.There are two significant parameters to evaluate the power line performance on preventing lightning strikes: one is the lightning trip-out rate,the other is the lightning withstand level of power line.Combining with the actual operation conditions and typical examples of lightning in the district 10kV distribution lines which belong to the city's suburb power supply bureau in Guangxi and located in the frequent lightning activity areas,it is analyzed and proposed that the problems of installation position,grounding resistance and grounding downlead exist in aspects of lightning protection measures of the regional distribution transformers,through grounding resistance measurement and on-site investigation of the distribution transformers which are susceptible to lightning strikes.The preventive measures of distribution transformer lightning prevention and corresponding rectification and improving measures are put forward which increase lightning withstand level of the power line and the reliability and security of power supply increase in distribution networks.