220 kV线路避雷器雷电绕击保护范围及优化应用研究

Study on Lightning Shielding Failure Protection Scope and Application Optimization for 220 kV Line Surge Arrester

线路避雷器作为一种防治线路雷害的措施其功效已被业界广泛认可,但是线路避雷器运维困难且成本较高,如何量化避雷器的保护范围、准确进行安装选点是影响避雷器应用效果的关键问题。基于电磁暂态计算软件ATP-EMTP建立220 k V输电线路雷击电磁暂态分析模型,分别对线路避雷器的有效保护范围与绕击高电位转移特性、线路避雷器绕击雷害治理与杆塔接地电阻的配合关系等问题进行研究。研究结果表明,避雷器的保护范围由雷电流大小、杆塔接地电阻和档距共同决定,避雷器安装点的绕击高电位转移会造成相邻杆塔的绝缘闪络;利用线路避雷器进行绕击雷害治理,杆塔接地电阻整治应考虑高电位转移的影响;治理易受大幅值雷电流绕击线路段,建议采用多基塔连续安装避雷器的方式。

Line lightning arrester as a measure to prevent lightning damage has been widely recognized. However, considering its high cost and difficulty of maintenance, how to get the quantized scope of arrester and accurately select the installation point is the key issue that impacts the effect of arrester application. This paper based on the electromagnetic transient analysis software ATP-EMTP to establish the lightning transient model of 220 kV transmission line to study the lightning protection performance of the surge arrester deeply. Some import issues are involved in the research, such as the effective protection scope and high potential transfer characteristic of the line lighting arrester, how to prevent lightning shielding failure, and the requirements on the grounding resistance and so on. Research results show that, the protection scope of arrester is commonly decided by lightning amplitude, tower grounding resister and span. High voltage from the lightning point where arrester is installed transfers to nearby tower and makes it flashover. When an＇ester is used, the high voltage transfer is needed to be considered. If a tower is always struck by high-amplitude lightning, two or more arresters in series are recommended to be used.