Implementation and test of fault line selector using zero module current travelling waves

The paper presents the implementation scheme of fault line selector using zero module current travelling waves with the application of a wavelet transform technique. The proposed scheme designs high-speed acquisition unit to achieve sampling current travelling wave signals, uses wavelet multi-resolution analysis to decompose the travelling wave signals, and extracts the local modulus maxima to represent the characteristics of the signals. In the implementation scheme the local modulus maxima of all lines are compared with each other to determine the fault line. In order to test the fault line selector implemented, one filed test has been carried out, which was presented in the paper. The field test result shows that the fault line selector can acquire single-phase-to-ground fault generated zero module current travelling wave information in neutral point non-effectively grounded distribution system and can identify the fault line correctly.