摘要
雷击输电线路杆塔时,杆塔接地装置的冲击电阻过大是造成雷电反击跳闸的主要原因。针对如何利用垂直接地极有效降低杆塔冲击接地电阻这一问题,文中建立典型杆塔接地装置仿真模型,研究了不同长度垂直接地极的影响范围;垂直接地极数量、长度对于杆塔接地装置降阻效果的影响。通过研究发现,不同长度垂直接地极影响范围不同:10 m长垂直接地极的影响范围大约为40 m,而3 m和5 m长垂直接地极的影响范围分别为5 m和20 m;在所添加垂直接地极总长度相同的情况下,所采用单根垂直接地极的长度越长,则降阻效果越好;随着垂直接地极数量的增加,其降阻率都不断趋向饱和。推荐在泄漏电流弱的地方添加尽可能长的垂直接地极,然后再根据其影响范围增加合适的垂直接地极数量。该结论可为杆塔接地体的设计及改造提供参考。
When lightning current striking the tower, the main cause of lightning trip-out is large impulse resistance of the tower grounding device. In view of how to use the vertical rod to reduce the impulse grounding resistance of tow- er, this paper establishes simulation model of typical tower grounding device to study the influence scope of different length vertical rod, the number and length of vertical grounding electrodes influence on resistance reducing effect. Through the study found that the different length of the vertical rod affects different area-the influence scope of 10 me- ter vertical rod is about 40 m, however, the influence scope of 3 m and 5 m vertical rod is about 5 m and 20 m respec- tively. When the total length of vertical grounding electrode under the same condition, the length of the vertical rod is longer, the resistance reduction effect is the better. With the increase in the number of vertical grounding electrodes, the resistance-reducing ratio is always saturated. This paper recommended that adding as much as possible long verti- cal rod at the place which the leakage current is weak, then according to the vertical rod＇ s impact area to increase the right number of vertical rod. This conclusion can provide technical reference for the design and reconstruction of the tower grounding device.
作者
高竹青
曹晓斌
杜俊乐
田明明
GAO Zhuqing;CAO Xiaobin;DU Junle;TIAN Mingming(Weifang Power Supply Company of State Grid Shandong Electric Power Company, Shandong Weifang 261021, China;School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, China)
出处
《高压电器》
CAS
CSCD
北大核心
2018年第4期182-187,共6页
High Voltage Apparatus
基金
国家自然科学基金杰出青年基金(51325704)~~
关键词
雷电
垂直接地极
接地体
杆塔
冲击接地电阻
lightning current
vertical rod
grounding body
tower
impulse grounding resistance
