某矿区电网进线段雷击事故分析及改造措施

Lightning strike accident analysis and modification measures for incoming lines of power grid in a mining area

  • 摘要: 针对屯兰变电站进线段杆塔遭受雷击导致主变压器被打坏的事故,着重对事故中进线段防雷保护措施所暴露出的问题进行剖析研究。研究结果显示,进线段防雷保护存在杆塔接地电阻超标、线路绝缘水平过高、避雷器的动作值与线路绝缘水平不匹配等问题。针对所存在的问题及隐患,提出了以下改造措施:利用树枝状放射接地体优化进线段杆塔冲击接地;采用可调式过电压保护间隙配合终端杆塔线路避雷器,形成进线段精细化综合保护;在进线段终端杆塔上装设无间隙的氧化锌避雷器。ATP-EMTP仿真结果表明,3种改造措施的综合作用能够有效降低雷电侵入波的幅值和陡度,保证矿区电网安全运行。

     

    Abstract: In view of the accident of main transformer being broken due to tower at incoming lines of Tunlan substation caused by lightning strike, the problems of lightning protection measures of the incoming lines were analyzed and researched. The research results show that the lightning protection of the incoming lines has problems such as excessive grounding resistance of the tower, too high lines insulation level, and mismatching between action value of arrester and lines insulation level. In view of the existing problems and hidden dangers, the following modification measures were proposed: optimize impulse grounding of the tower at incoming lines by using dendritic radioactive grounding body; use adjustable overvoltage protection gap to match lines arresters on the terminal tower, so as to form refined comprehensive protection of the incoming lines; install gap-free zinc oxide arrester on the terminal tower at incoming lines. The ATP-EMTP simulation results show that the combined effects of the three modification measures can effectively reduce amplitude and steepness of lightning intruding wave and ensure safe operation of the mine power grid.

     

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