线路高阻接地叠加开关失灵的保护改进方法  

Improvement Method of High Resistance Grounding Superimposing BreakerFailure Protection of Transmission Line

作　　者：田顺强 李霞 刘洋 Tian Shunqiang;Li Xia;Liu Yang(State Power Investment Group Guizhou Jinyuan Weining Energy Co.,Ltd.,Guiyang 550081,China;Southwest Electric Power Design Institute Co.,Ltd.,Chengdu 610056,China)

机构地区：[1]国家电投集团贵州金元威宁能源公司,贵阳550081 [2]西南电力设计院有限公司,成都610056

出　　处：《机电工程技术》2025年第3期154-157,163,共5页Mechanical & Electrical Engineering Technology

摘　　要：随着新型电力系统建设的推进,对于新能源大规模接入的区域电网,新能源场站在短路故障状态下具有幅值受限、频率偏移、相角受控畸变等相对弱故障特性。如发生220 kV线路高阻接地叠加开关失灵的故障,由于故障量不明显而易导致220 kV失灵保护的选择性和灵敏性不足。据此,针对新能源接入较多的一座500 kV变电站区域电网实际发生的一起220 kV线路高阻接地叠加开关失灵的典型故障案例,对当前220 kV失灵保护与500 kV主变后备保护配合的选择性不足进行分析论证,针对性地提出了提升220 kV失灵保护选择性和灵敏性的3个改进方法,其中的220 kV失灵保护判别逻辑优化方案中,引入了变化量或稳态零序电压和支路零序电流与门判据,提高了220 kV失灵保护的选择性和灵敏性,也起到可靠防范CT拖尾、误开入、误碰等导致失灵保护误动作的闭锁效果。With the advancement of new power system construction,for regional power grids with large-scale integration of new energy,new energy stations have relatively weak fault characteristics such as amplitude limitation,frequency offset,and phase angle controlled distortion under short-circuit fault conditions.If a fault occurs in the high resistance grounding superimposed switch failure of a 220 kV line,due to the unclear fault amount,it is easy to lead to insufficient selectivity and sensitivity of the 220 kV failure protection.Therefore,based on a typical failure case of a high resistance grounding superimposed switch failure of a 220 kV line actually happened in a 500 kV substation network region with relatively large amount of new energy integration,the lack of selectivity in the current coordination between 220 kV failure protection and 500 kV main transformer backup protection are analyzed and demonstrated,and proposes three targeted improvement methods to enhance the selectivity and sensitivity of 220 kV failure protection.In the optimization scheme of 220 kV failure protection discrimination logic,the variable or steady-state zero sequence voltage and branch zero sequence current and gate criterion are introduced,which not only improves the selectivity and sensitivity of 220 kV failure protection,but also reliably prevents the interlocking effect of failure protection misoperation caused by CT tailing,accidental opening,and accidental collision.

关 键 词：新能源 高阻接地 失灵保护 零序电压 零序电流 闭锁判据 

分 类 号：TM862[电气工程—高电压与绝缘技术]