沙尘暴和沙尘电对输电铁塔塔头电场分布的影响

沙尘暴是西北地区频发的一种自然灾害.科研人员发现沙尘暴不仅会改变空气的绝缘性能,而且由于沙尘颗粒之间的摩擦.会在空间产生强烈的电场(沙尘电),这可能对输电线路安全运行产生影响.文章主要针对沙尘暴和沙尘电对输电铁塔塔头工频电场分布的影响进行研究.利用矩量法并引进复电阻率的概念,模拟分析典型铁塔塔头周围均压环和导线表面在不同外加电场作用下的最大电场强度,研究沙尘电对输电铁塔塔头电场分布的影响,并研究通过对导线和均压环配置的优化来降低中相导线表面最大电场强度的具体措施.研究发现,强沙尘暴时,强烈的沙尘电有可能使部分导线表面的最大电场强度增大,影响电力输送安全,但可以通过优化导线布置来改善.

Influence of Sand and Dust Storms and Wind-sand Electricity on Electric Field Distribution around Head of Transmission Tower

Sand and dust storms are often occurred in Northwest of China. The scientists have found that the sand and dust storms can not only change the insulation capability of air, but also generate strong electric field due to the friction among the sand and dust, which may affect the safe operation of the power transmission lines. In this paper, the influence of the sand and dust storms as well as wind-sand electricity on the power-frequency electric field distribution around head of transmission tower is investigated. Based on the moment method, by introducing the concept of complex resistivity, a numerical model to analyze the maximal electric field strength on the surfaces of the conductor and grading rings under the electric field around the transmission tower is developed. The influence of the wind-sand electricity on the electric field distribution around the head of transmission tower is analyzed. The measures to reduce the maximal electric field strength on the surface of the middle phase of transmission line by optimizing the configuration of the conductor and grading ring is also investigated. It is found that the strong wind-sand electricity may increase the maximal electric field strength on the surfaces of the conductor and grading rings, which may affect the safe operation of the power transmission lines. However, this situation can be improved by optimizing the conductor arrangement.