Faulty line selection based on waveform feature clustering in time domain for resonance grounding system

The waveform similarity of line zero-sequence currents after the single-phase grounding fault of resonance grounding system is analyzed based on its zero-sequence network and a method of faulty line selection based on the waveform feature clustering in the time domain is proposed for it. The line zero-sequence current waveform of the first post-fault half-period is decomposed in histograms and the relative entropy matrix is adopted to reflect the state difference among the zero-sequence currents, as well as their polarity information. Combined with the amplitude information, an integrated relative entropy matrix is established to represent the time-domain waveform feature of transient zero-sequence currents. The fuzzy KFCM (Kernel Fuzzy C-Means) without the threshold setting is used to detect the faulty line. The proposed method is verified by the simulations under different working conditions and the results show that, it is immune to the arc fault, noise disturbance, non-synchronized sampling and compensation degree. © 2015, Electric Power Automation Equipment Press. All right reserved.