摘要
基于增益阻抗概念,提出了一种全新而有效的解决中性点非有效接地系统单相接地选线问题的方法:即利用单相接地故障过程中产生的暂态扰动来寻求非故障侧的增益阻抗,借助该阻抗和相应判据实现故障线路的判定。如果故障发生在测量点上游,测得的增益阻抗为下游等效阻抗;如果故障发生在下游,则增益阻抗为上游等效阻抗的负值。借助等效序网论证了采用零序增益阻抗具有更强的可实施性,进而针对中性点不接地系统和谐振接地系统分别推导出了基于基波和五次谐波零序增益阻抗的单相接地故障选线判据。大量仿真和动模实验结果都验证了该方法的有效性。该方法物理概念明确,实施简单。
Based on incremental impedance theory,a method of single-phase grounding line detection for power systems ineffectively grounded at neutral point is proposed,which applies the incremental impedance as criterion. The transient disturbance produced by the single-phase grounding fault is used to estimate the incremental impedance of normal side. If the grounding point is at upstream side of measuring point,the measured incremental impedance is the equivalent impedance of downstream side;if it is at down side,the measured incremental impedance is the negative of the equivalent impedance of upstream side. Equivalent sequence network is used to demonstrate that the zero- sequence incremental impedance is more sensitive for faulty line detection. The detection criteria of systems ungrounded and resonantly grounded at neutral point are set based on fundamental and 5th hamonic zero-sequence incremental impedances respectively. Simulation and lab experiments prove that,the proposed mdthod is effective with clear physical concept and easy implementation.
出处
《电力自动化设备》
EI
CSCD
北大核心
2007年第11期18-21,54,共5页
Electric Power Automation Equipment
关键词
增益阻抗
非有效接地系统
不接地系统
谐振接地系统
故障选线
incremental impedance,ineffectively grounded systems
ungrounded systems
resonantly grounded system
faulty line detection
