Single-phase-to-ground fault line detection for distribution network based on optimal finite impulse response filter and hierarchical clustering

Due to the impacts of unconspicuous fault characteristics, noise interference, imbalanced operation condition of distribution network and so on, there are insufficiencies in reliability and universality in existing fault line detection methods for single-phase earth fault occurred in small current grounding system. A new fault line detection method for single-phase earth fault occurred in small current grounding system is proposed. Based on frequency characteristics of fault transient quantity the proposed method filters interference factors by finite impulse response (FIR) filter and extracts available fault characteristics; utilizing hierarchical clustering and based on the filtered waveform, the variation trend of transient zero-sequence capacitive current component at the beginning end of the faulty feeder is different from variation trends other healthy feeders, so the faulty feeder can be detected. Simulation results show that using the proposed method the data decomposition step by step can be avoided, and the faulty feeder under various fault conditions can be reliably detected, besides, the demand on the sampling frequency is decreased, thus the system resource can be saved and the proposed method is easy to implement. ©, 2014, Chinese Society of Astronautics. All right reserved.