Analysis of the fault type for adaptive single-phase autoreclosure

This paper analyzes the characteristic of the recovery voltage when single phase earth fault occurs in EHV/UHV transmission line with shunt reactor. According to the different frequency characteristics of the recovery voltage, a new method based on power spectrum to distinguish the temporary faults from the permanent faults in EHV/UHV transmission lines is proposed. Through using the distribution of spectral line nearby the power frequency in power spectrum, this method can identify the type of a fault. The criterion that doesn´t need high frequency contents is easy to set and implement. Power spectrums are calculated and analyzed by use of MATLAB/ SIMULINK. The results show that the proposed method is accurate and feasible.