Study on lightning protection of 110kV transmission lines in Qinghai-Tibet railway

Lightning protection and grounding is an important problem in Qinghai-Tibet railway. A Study based on analysis of thunderstorm activity was given to find out a way to improve lightning withstand level of transmission lines in Qinghai-Tibet railway. This paper analyzed thunderstorm activity to know its characteristics and rules. Then cloud-to- ground (CG) lightning and lightning current amplitude were analyzed. For Qinghai-Tibet Railway more in frozen region and very difficult to decrease grounding resistance of grids, a simulation was done about the lightning withstand level of 110 kV transmission lines and a discussion was given about effects of it by different spanning method of lightning arrester. At last, a conclusion was given that the lightning withstand level can be increased by spanning lightning arrester properly and an analysis was given to the reliability of the transmission lines after spanning lightning arrester. The result of this paper provided a feasible method to improve lightning withstand level about transmission lines and a theory supporting about the design and construction of Qinghai-Tibet railway.