Faulty line selection with non-power frequency transient components of distribution network

A neutral non-effectual grounding distribution network model is established with Matlab/Simulink and simulated for many cases.As the non-effectively grounding distribution system has distinct transient components at the beginning of single-phase-to-earth fault,HHT(Hilbert-Huang Transform) is applied to calcu-late the transient frequency components of zero-sequence current,from which the non-power frequency transient components are extracted to detect the single-phase-to-earth fault.Simulative results suggest that,the polarity of non-power frequency component of faulty line is contrary to that of healthy line and the amplitude of non-power frequency of faulty line is much larger than that of healthy line within the one tenth of period after fault.It is proposed to apply the non-power frequency transient components in the faulty line selection for the single-phase-to-earth fault of distribution network.Results indicate it is precise and reliable.