Study on electric field distribution characteristics of the maintenance area when UHV AC transmission line crossing 220 kV tower

• Main Authors: Feng Huo, Wei Lu, Zhibin Qiu, Daochun Huang, Congpeng Huang
• Format: Article
• Language: English
• Published: Wiley 2019-04-01
• Series: The Journal of Engineering
• Subjects: power overhead lines; power transmission lines; finite element analysis; electric fields; power grids; poles and towers; crossing angle; maintenance area; lower tower; line worker body surface electric field; maximum electric field strength; cross-angle decreases; crossing height; electric field distribution characteristics; multicircuit overhead transmission lines; power-frequency electric field; China power grid; overhead UHV AC double circuit transmission line; UHV AC transmission line crossing tower; three-dimensional finite element model; span height; offset distance; voltage 220.0 kV; voltage 1000.0 kV
• Online Access: https://digital-library.theiet.org/content/journals/10.1049/joe.2018.8499

With the rapid development of China's power grid, it is becoming increasingly common that the multi-circuit overhead transmission lines cross over each other. It is important to design the lines' configuration reasonably and evaluate whether the power-frequency electric field meets the national standard. In order to analyse the electric field distribution in the maintenance area of the 220 kV tower with an overhead 1000 kV UHV AC double circuit transmission line, a three-dimensional finite element model of the crossing tower and transmission line was established. The influences of the crossing angle, span height and offset distance on the electric field distribution in the maintenance area of the lower tower and the line worker body surface electric field were analysed. The results show that the maximum electric field strength of the tower will increase 28.7% when the cross-angle decreases from 90° to 30°, and the impact of span height on the electric field distribution is much smaller at 90° than that at 30°. At 60°, when the crossing height is 16 m, the electric field strength on the worker's body surface is much less than the limiting value.