摘要
配电线路因雷电感应导致故障的比例要远高于雷电直击,因此需要合理分析配电系统终端的雷电感应过电压防护。通过EMTP中的MODEL模块编程计算线路雷电感应过电压,分析雷击点距线路垂直距离和回击速度对配电终端过电压的影响,讨论不同负载性质下终端过电压随低压线路长度趋势,最后分析配电终端前安装SPD的防护效果。分析结果表明:10 kV线路附近发生雷击时,传递至低压配电终端的雷电感应过电压幅值仍然较高,会超过设备冲击耐受电压;配电终端雷电过电压随着雷击点距线路垂直距离的增加而降低,随着回击速度的增加而增大;配电终端过电压在阻性负载与感性负载幅值较小情况下随着220 V线路长度增加而降低,在容性负载情况下随着线路长度的增加而增大。配电终端前安装SPD后能够有效降低负载过电压,较好地保护终端设备。
The main factor of line faults caused by lightning is induced lightning rather than direct lightning,so it is necessary to analyze protection against lightning induced overvoltage on the distribution terminals. Lightning induced overvoltage was calculated by means of model in EMTP. Influence of vertical distance from lightning strike point to the overhead line and the current wave propagation speed on overvoltage of the distribution terminal were presented. Overvoltages of the distribution terminal with different line length and load types were also analyzed. Finally,effect of installing surge arresters was discussed.Results show that: transferred overvoltage due to lighting induction from 10 kV line remains high. Overvoltage of the distribution terminal increases with the decreasing of vertical distance from lightning strike point to the overhead line as well as the increasing of current wave propagation speed. Overvoltage increases with the increasing of line length under capacitive load while decreases with the increasing of line length under minor amplitude resistive load or inductive load. he load overvoltage can be effectively reduced,and the terminal equipment can be better protected when surge arresters are installed.
作者
郑亮
王潇煜
刘财华
ZHENG Liang;WANG Xiaoyu;LIU Caihua(NARI Group Corporation/State Grid Electric Power Research Institute,Nanjing 211106,China)
出处
《电瓷避雷器》
CAS
北大核心
2019年第1期164-168,173,共6页
Insulators and Surge Arresters
