35kV中性点不接地系统架空线路雷击风险评估  

Lightning Risk Evaluation on 35 kV Overhead Lines of Ungrounded Neutral Point System

作　　者：张文锋 李志伟 张国建 Zhang Wenfeng;Li Zhiwei;Zhang Guojian(Dali Power Supply Bureau of Yunnan Power Grid LLC,Dali 671000,China)

机构地区：[1]云南电网有限责任公司输电分公司,云南昆明655000

出　　处：《云南电力技术》2023年第2期57-61,共5页Yunnan Electric Power

摘　　要：架空输电线路雷击计算中,通常一相发生雷击闪络即认为引起雷击跳闸,但对于中性点不接地系统,单相故障后可持续运行2 h,因此需要两相或三相同时雷击闪络才造成线路跳闸。为此,基于两相同时闪络确定的耐雷水平和建弧率计算雷击跳闸率,作为雷击风险评价指标,再结合线路雷电活动、杆塔结构、绝缘配置对架空线路逐基杆塔批量评估雷击风险,针对薄弱区段给出改造方案。通过云南某35 kV中性点不接地系统架空线路应用了本评估方法,验证其合理性。Lightning trip-out rate(LTOR)calculation is usually based on that single-phase flashover introduced by lightning could cause trip-out for overhead transmission lines,while ungrounded neutral point power system is allowed to continue to run for another 2 hours when it occurs,therefore only two or more phases lightning flashover could cause subsequent trip-out.LTOR is introduced as an index for lightning risk evaluation based on withstanding level and arc establishment rate under two-phases flashover tower by tower,and lightning activity,tower structure and insulation condition are taken into account.The poor section in lightning protection is suggested by a reform scheme.The method is proved reasonable through a 35 kV overhead line of ungrounded neutral point power system in Yunnan province.

关 键 词：雷击 架空线路 风险评估 中性点 

分 类 号：TM74[电气工程—电力系统及自动化]