Research Of A New Line Arrester And Its Impact On Lightning Protection Of Line In Complex Terrain

With the rapid development of modern society, the importance of power system has become increasingly prominent, and its safety and reliability has attracted more and more attention. However, as a major component of power system, transmission line is exposed in the open field permanently, which makes it vulnerable to lightning, resulting in line failure, and leading to enormous social and economic losses. Lightning activity is frequent and the terrain is complex in Sichuan province. Its special geographical conditions not only lead to the difficulty of reducing the grounding resistance, but also make traditional lightning protection means like lightning shield wire invalid. These eventually lead to frequent lightning trip of transmission lines in Sichuan in lightning-prone season, and lightning damage of the 220 kV transmission lines is most severe. Research shows that the line arrester can simultaneously prevent both back striking and shielding failure tripping. It's an effective measure to reduce line lightning trip accidents, improve power system's reliability and reduce the operating costs. For line arrester, the main work of this paper is as following:(1)Based on the shortcomings of the current line arresters widely used, a new 220 kV line arrester is proposed, which is easy to install and maintain. This arrester has good operating reliability, high regulation accuracy and maintenance-free function.(2)Using Auto CAD and ANSYS to establish related models of three type 220 kV arresters etc..and simulate the potential distribution and electric field distribution of ZnO varistors in these three arresters. Analyzed the effect of optimization measures like corona rings and verified the electric feasibility of this new line arrester.(3)Based on the actual line parameters of 220 kV ShanYue transmission line, This paper used EGM and ATP-EMTP program to analyze the influences of hillside inclination, large span and impulse grounding resistance on line's lightning withstand performance.(4)Selecting ShanYue transmission line as the research object, This paper used ATP-EMTP program to simulate the new line arrester's efficacy to prevent lightning damage in complex terrain and lightning-prone areas. Calculated and analyzed the impact of different new line arrester installation programs on line's lightning withstand performance. Finally, some principled recommendation about the new line arrester's installation program was given out.Simulation results show that potential distribution and electric field distribution of ZnO varistors in the new line arrester have met the requirements of practical engineering after taking appropriate optimization measures. Its application in transmission line can significantly improve the lightning withstand performance, and its further development and practical application are able to be expeted.