A study of earth fault detection by comparing phase of initial transient traveling wave
Yonghui Wang · Electric Power · 2008
The characteristic of traveling waves produced by a single-phase earth fault in an ineffectively grounded distribution grid was discussed.A complex frequency B-spline(CFBSP) wavelet was presented to analyze the singular signals of the zero modes of the fault traveling waves in the initial process of the failure,and the wavelets coefficient maximum polarity and phase angle of the zero mode of the fault feeder traveling wave current are right the inverse of the others.A novel earth failure detection technique was introduced to distinguish the fault feeder by comparing the wavelets coefficients maximum polarity and phase-angle of the zero modes of the traveling waves' currents in some scales.The influences of the fault spot intermittent arc,transformer and its neutral point were proved to be feeble.The detection technique is very exact,available and universal,which is proved by a great deal of simulating test.