220kV带串联间隙线路避雷器保护性能研究

Protection Performance Investigation of 220 kV Line MOA with External Series Gap

鹰潭供电公司220 kV月铜线发生的两起雷击跳闸故障,故障相均安装了线路避雷器,因此,供电公司对线路避雷器的保护效果产生了疑虑。为深入验证线路避雷器的保护效果,避免类似事件的再次发生,国网江西省某电力科学研究院通过开展线路避雷器雷电冲击50%放电电压试验和工频湿耐受电压试验对避雷器间隙距离进行了深入研究,得到了不同间隙距离线路避雷器与不同绝缘子串的配合裕度,在此基础上给出220 kV线路避雷器间隙距离推荐值(840±10)mm,可以同时满足保护可靠性与运行安全性的要求。

There were twice lightning trip-out breakdowns occurred on 220 kV Yuetong line in Yingtan Electric Power Company in Jiangxi although the metal oxide surge arrester （MOA） is mounted on the fault phase. In order to verify the protection effects of the line MOA and to avoid similar incidents, the investigations are made which include the 50% discharge voltage test under lightning impulse and the power frequency withstand voltage test under wet condition are carried out to the series gap of the MOA. The co-ordination margin between the different gap clearances and the line MOA i＇s obtained. Based on the above research, the gap distance of （840±10） mm for 220 kV line MOA is recommended, which can satisfy the requirements both reliability of protection and safety of operation.