Single-phase Ground Fault Detection Method of Resonant Grounding System Based on Gray Correlation Degree
The single-phase grounding fault of resonant grounding system is difficult to detect,mainly because the current of resonant grounding system is very small.For the similarity of instantaneous zero sequence current waveform between fault phase and non-fault phase is less than that between two non-fault phases,a feeder detection protection scheme based on gray level relationship between curves is proposed in this paper.The slope relation de-gree is selected as a grey relation degree to represent the similarity of transient zero sequence current waveform be-tween one feeder and other feeders,and the slope relation matrix is established to represent the relation between all feeders.The protection criterion based on slope relation matrix can be used to detect single-phase ground fault feed-ers.The method presented in this paper is currently suitable for systems with at least three or more feeders.The ef-fectiveness and reliability of the scheme are verified by EMTP simulation results and adaptability analysis.
NETL
NSTL
万方数据
