CAJ | 학술논문

一般大型水电站所建山区土壤电阻率很高，而且系统入地短路电流大，其接地系统设计较常规发变电站困难得多。针对此问题，结合锦屏二级水电站的实际情况，对高压母线发生接地故障时实际作用在站内二次设备上的过电压大小进行了理论分析和仿真计算。结果表明，作用在设备绝缘的过电压大小取决于接地网的网内电位差而非总地电位升，锦屏二级水电站在对外采取地电位隔离措施的前提下，其接地系统的设计可按开关站与厂房之间的接地网网内电位差≤1．4kV来进行控制。最后提出了大型水电站接地系统安全设计的准则，可为其他类似的工程设计和研究提供一定的参考。
일반대형수전참소건산구토양전조솔흔고，이차계통입지단로전류대，기접지계통설계교상규발변전참곤난득다。침대차문제，결합금병이급수전참적실제정황，대고압모선발생접지고장시실제작용재참내이차설비상적과전압대소진행료이론분석화방진계산。결과표명，작용재설비절연적과전압대소취결우접지망적망내전위차이비총지전위승，금병이급수전참재대외채취지전위격리조시적전제하，기접지계통적설계가안개관참여엄방지간적접지망망내전위차≤1．4kV래진행공제。최후제출료대형수전참접지계통안전설계적준칙，가위기타유사적공정설계화연구제공일정적삼고。
Generally a large hydropower station is located in the mountain area of high soil resistivity and the grounding grid short-circuit current of the system is very big, so the design of the grounding grid is much difficult than that in the ordinary power stations and substations. According to real situation of Jinping lI hydropower station, we theoretically analyze and simulate the actual voltage imposed on the secondary equipment when grounding fault occurs on the high voltage bus. The results show that the over-voltage imposed on equipment insulation depends on grounding grid potential difference rather than GPR, and if the ground potential is isolated from outside, the design of Jinping II hydropower station＇s grounding grid can be Controlled by the qualification that the grounding grid potential difference between switchyard and factory building is lower than 1.5 kV. Finally the safety design principle of large hydropower station＇s grounding system is proposed which can provide a reference for other projects.