PD pulse propagation studies using the wavelet transform

This paper presents an analysis of partial discharge (PD) pulse propagation in a rotating machine stator winding in the phase-space domain using the wavelet transform. The experimental results of PD pulse propagation in an induction motor stator winding are analysed in continuous wavelet transform, and the coupling and traveling behaviour of pulses with different risetime in propagation are investigated in multiresolution analysis. In particular, this paper focuses on the mechanisms of pulse propagation, i.e., series mode propagation through the windings and coupling mode, using the new analysis tool. The paper demonstrates that the proposed analysis tool can provide reliable information for recognising the nature of PD pulse propagation and, in turn, may prove useful in the longer term in determining the location of discharge activity (and hence degradation) in distributed impedance plant