配电网防雷的难点及对策研究

针对配电网存在易受雷击侵害和故障定位困难的问题,研制了一种新型喷气式并联间隙灭弧装置。该装置借鉴"疏导型"并联间隙的思想,首先对雷击后的工频续流疏导引流,然后喷射能量巨大的气体,通过外力强制灭掉工频续流电弧,气体流速越大,绝缘恢复时间越短。对35kV线路的灭弧装置进行试验,灭弧时间为3ms,可在继电保护启动前完全灭掉工频续流电弧。在广西合浦和大化地区配电网中应用该装置,实际运行结果表明该装置能有效降低线路跳闸率。该装置通过改进也可运用到110kV、220kV等输电线路上。

Difficulties and Countermeasures for Lightning Protection of Distribution Network

To solve the distribution network＇s problems of vulnerability to lightning and difficulty in fault location,a new air-jetting shunt-gap arc extinguisher has been developed.Benefiting from the concept of ＂diverting-type＂ shut gap,the device first diverts the power-frequency follow current after lightning,then ejects gas with giant energy to compulsorily extinguish power-frequency follow current arc by external force;the greater the gas flow velocity,the shorter the insulation recovery time.In the test on arc extinguishers of 35 kV lines,the arc extinction time was 3 ms,able to fully extinguish power-frequency follow current arc before starting relay protection.Applications of the device in Hepu and Dahua in Guangxi,China show that it can reduce line tripping rate effectively.Upon improvement,the device can also be applied to transmission lines of 110 kV and 220 kV,etc.