中性点经消弧线圈并联动态电阻接地分析  

Analysis of the neutral point grounded by parallel dynamic resistance through arc suppression coil

作　　者：郭左 李云飞 吕健 王梦珂 田恬 李传辉 陈智勇 GUO Zuo;LI Yunfei;LV Jian;WANG Mengke;TIAN Tian;LI Chuanhui;CHEN Zhiyong(Lianyungang Power Supply Branch of State Grid Jiangsu Electric Power Co.,Ltd.,Lianyungang 222000,China;School of Electrical Engineering,China University of Mining and Technology,Xuzhou 221008,China)

机构地区：[1]国网江苏省电力有限公司连云港供电分公司,江苏连云港222000 [2]中国矿业大学电气工程学院,江苏徐州221008

出　　处：《电气应用》2023年第3期15-22,共8页Electrotechnical Application

摘　　要：随着配电网容量的不断扩大以及电缆线路的广泛使用,消弧线圈并联小电阻接地方式在10 kV配电网中的使用占比逐步上升。传统消弧线圈并联小电阻接地方式吸收了消弧线圈接地和小电阻接地的优点,但对于某些工况仍有部分缺点,比如系统发生高电阻接地故障时,由于故障特征不明显导致保护可能误动作,可靠性下降。针对此问题,研究改进接地方式为消弧线圈并联动态电阻接地,并根据动态电阻前后状态的零序电流有功分量增量实现高电阻接地故障选线。通过理论分析,提出以并联电阻前后零序电压与零序电流夹角为动作判据,解决高阻接地故障选线失灵问题。With the continuous expansion of distribution network capacity and the wide use of cable lines,the use of arc suppression coil parallel small resistance grounding mode in 10 kV distribution network has gradually increased.The traditional parallel small resistance grounding mode of arc suppression coil absorbs the advantages of arc suppression coil grounding and small resistance grounding,but it still has some disadvantages for some working conditions,such as when a high resistance grounding fault occurs in the system,the protection may malfunction and the reliability may decline due to the unobvious fault characteristics.To solve this problem,the improved grounding method in this study is parallel dynamic resistance grounding with arc suppression coil,and based on the active component increment of zero sequence current before and after the dynamic resistance,high resistance grounding fault line selection is realized.Through theoretical analysis,the angle between zero sequence voltage and zero sequence current before and after the parallel resistance is proposed as the action criterion to solve the failure of line selection for high resistance grounding fault.

关 键 词：配电网 中性点接地 动态电阻 高阻接地故障 供电可靠性 

分 类 号：TM862[电气工程—高电压与绝缘技术]