Electric Power ›› 2021, Vol. 54 ›› Issue (8): 91-97.DOI: 10.11930/j.issn.1004-9649.202102077

Previous Articles     Next Articles

Three-Dimensional EGM Study on Shielding Failure Rate of Transmission Lines Considering Canyon Depth

BI Jieting1,2   

  1. 1. Jiangsu Vocational College of Electronics and Information, Huaian 223003, China;
    2. School of Electrical Engineering, Guangxi University, Nanning 530004, China
  • Received:2021-02-23 Revised:2021-03-26 Published:2021-08-05
  • Supported by:
    This work is supported by Major Science and Technology Special Funded Projects in Guangxi Autonomous Region (Key Technologies and Industrialization of Lightning Protection for Overhead Transmission Lines and High-Speed Railway Catenary, No.AA18242050), and the National Natural Science Foundation of China (Research on the Mechanism of Using Impulse arc Energy to Suppress Power Frequency arc Formation Rate, No.51467002)

Abstract: A considerable number of high voltage transmission lines are built across deep valleys. In the past, no specific study was carried out on the valley topography in building models for calculating shielding failure rate of transmission lines, and the shielding effect of the unique topography of valleys was ignored. In this paper, a new three-dimensional electrical geometrical model (EGM) based on valley depth is established to directly study the transmission line shielding failure rate through calculating the exposed and protected cambered surface areas. The effectiveness of the proposed three-dimensional EGM method is verified through an example, and the valley topography is proved to be one of the main causes for frequent lightning trip-out of transmission lines. Avoiding complicated calculus operation, the proposed method is mainly applicable in mountain valley area. With consideration of the canyon depth and the slope angle of the ground, the calculated shielding failure rate is closer to the actual situation, which is significant for application.

Key words: canyon depth, three-dimensional EGM, transmission line, shielding failure rate