周象贤,孙翔,金佳敏
ZHOU Xiangxian,SUN Xiang,JIN Jiamin

• 1:国网浙江省电力公司电力科学研究院
• 2:国网浙江省电力公司温州供电公司

摘要(Abstract)：

110 k V与220 k V变电站中存在部分中性点不接地变压器,其中性点与地间一般接有保护间隙。运行经验表明,终端变中不接地变压器在进线单相接地故障时容易发生间隙击穿并导致间隙过流保护动作,但目前的研究都没有解释为何非终端变不容易发生此类事故。通过典型的终端变与非终端变变压器中性点过电压的仿真,对比分析了这两类变电站在进线单相接地故障时的电气量变化过程,从而解释了终端变易发生保护动作的原因。
Some transformer neutral points in 110 k V and 220 k V substations are not grounded, and there is usually a protection gap between neutral point and ground. The operation experience shows that the neutral gap of transformer in terminal substation is prone to be broken down during single phase grounding fault,leading to over current protection of protection gap. However, the existing research has not explained why the non-terminal substations are invulnerable to such accidents. Through simulation on neutral point overvoltage of transformers in both terminal and non-terminal substations, the paper compares and analyzes electrical quantity alternation of the two substations during single-phase grounding fault, which explains the reason of protection action that frequently occurs in terminal substation.

关键词(KeyWords)： 终端变电站;中性点;过电压;仿真
terminal substation;neutral point;overvoltage;simulation

Abstract:

Keywords:

基金项目(Foundation):

作者(Author): 周象贤,孙翔,金佳敏
ZHOU Xiangxian,SUN Xiang,JIN Jiamin

DOI: 10.19585/j.zjdl.2015.05.001

参考文献(References)：

• [1]于化鹏,陈水明,余宏桥,等.110 k V变压器中性点过电压的计算及其保护策略[J].电网技术,2011,35(3):152-158.
• [2]蒋伟,吴广宁,张雪原,等.单相短路对110 k V和220 k V变压器中性点绝缘的影响及其防护[J].变压器,2007,44(11):5-8.
• [3]DL/T 620-1997交流电气装置的过电压保护和绝缘配合[S].北京:中国电力出版社,1997.
• [4]何智强,单周平,李欣.220 k V变电站主变保护间隙击穿原因分析[J].湖南电力,2013,33(4):41-43.