摘要
提出一种针对中性点经消弧线圈接地系统的基于单相接地故障综合工频稳态量分析的选线算法,使选线的准确性不受零序电压与电流相位误差的影响,同时也使零序电流互感器特性的非一致性造成的测量误差被抵消。首先,计算出流经各馈出线零序电流互感器的电流;再将各馈出线的零序测量电流与补偿电流求相量和,得出各馈出线的复合电流,并将各馈出线的复合电流逆时针旋转90°,得出各馈出线的故障判断电流;然后将各馈出线零序测量电流和本馈出线故障判断电流分别"点积"得到各馈出线的故障判断量P,其中非故障馈出线判断量大于零,故障馈出线判断量小于零。最后,利用Matlab建立系统模型,对单相接地的各种情况进行仿真,并对仿真结果进行分析比较,显示了该算法具有较高的保护裕度。
A faulty line selection algorithm is proposed for the single-phase grounding fault of power system with neutral point grounded via arc- suppression coil,which is based on the synthetic steady component analysis. The correctness of faulty line selection is not influenced by the phase error of zero- sequence voltage and current,and the measurement error caused by the inconsistency of current transformer is counteracted. The current of zero- sequence current transformer is calculated,and the vectorial sum of zero -sequence current and compensation current is then calculated as the composite current,which rotates coun- terclockwise for 90 degree to obtain the fault detection current. The measured zero-sequence current of each feeder is dot- multiplied by the corresponding fault detection current to obtain the fault estimation P. The estimation P of faulty line is negative while those of healthy lines are positive. Various situations of single-phase grounding fault are simulated with Matlab and the simulation results are analyzed,which show the algorithm has a higher protection margin.
出处
《电力自动化设备》
EI
CSCD
北大核心
2009年第7期89-92,共4页
Electric Power Automation Equipment
关键词
消弧线圈
故障选线
补偿电流
中性点接地
MATLAB
arc-suppression coil
faulty line selection
compensation current
neutral point earthing
Matlab
