某城市110 kV钢管塔接地安全校核及改进设计

Grounding Safety Check and Improved Design of 110 kV Steel Pipe Tower in a City

城市输电钢管塔大都位于人流密集区域,其接地装置需要考虑跨步电压等安全性指标。目前,输电杆塔接地的安全设计研究较少。本研究从人体允许的安全标准出发,研究了输电杆塔接地设计的安全指标及其计算方法。利用CDEGS软件计算了现有城市输电钢管塔接地装置在工频短路和雷击故障下的接触电压和跨步电压分布,认为工频跨步电压超标是目前城市输电钢管塔接地安全存在的主要问题。针对输电杆塔接地普遍采用的水平射线接地体,提出在水平射线末端添加水平夹角射线结构,辅以垂直接地极的方法来降低最大工频跨步电压。通过对末端射线夹角大小及垂直接地极的布置方式的优化设计,结合实际设计施工要求,提出了输电钢管塔接地综合安全优化设计方案,可以综合满足接地电阻、安全指标和实际施工要求。所得结果可为该城市输电线路杆塔接地的设计和施工提供方法指导。

Most of the urban power transmission steel pipe towers are located in crowded areas, and their grounding devices need to consider safety indicators such as step voltage. There are few researches on the safety design of power transmission tower grounding. Based on the safety standards allowed by the human body, theauthor studies the safety indicators and calculation methods of the grounding design of power transmission towers. CDEGS software was used to calculate the touch voltage and step voltage distribution of the existing urban power transmission steel pipe tower grounding device under power frequency short circuit and lightning fault. It is believed that excessive power frequency step voltage is the main problem in the grounding safety of urban power transmission steel pipe towers. Aiming at the horizontal ray grounding body commonly used in the grounding of power transmission towers, it is proposed to add a horizontal angle ray structure at the end of the horizontal ray, supplemented by a vertical grounding pole to reduce the maximum power frequency step voltage. Through the optimization design of the angle of the end rays and the arrangement of the vertical grounding electrode, combined with the actual design and construction requirements, a comprehensive safety optimization design plan for the grounding of the transmission steel pipe tower is proposed, which can comprehensively meet the grounding resistance, safety indicators and actual construction requirements. The results obtained can provide method guidance for the design and construction of the grounding of the transmission line towers in this city.