A novel approach to faulted-phase selection using current traveling waves and wavelet analysis

The early traveling wave faulted-phase selectors, due to lack of effective tool to process transient signals, had to directly used instantaneous values of signals so that they cannot overcome such bad influence as noise disturbance. Fortunately, wavelet analysis, with its time-frequency localization ability and the wavelet transform modulus maxima (WTMM) concept, is well suited to treat with singularity of fault-generated traveling waves in EHV/UHV transmission lines. This paper presents a novel approach to fast and accurate phase-selection, which used the WTMM of initial model current traveling waves according to the fault characteristic relations deduced from the boundary conditions of various types of faults. The criterion is explicit in characteristics and physical concepts, and is apt to be realized. A large number of EMTP simulations demonstrated the new faulted-phase selection algorithm.