Analysis of Power Transient Disturbances using Wavelet Transform Modulus Maxima Technique
DT Nguyen, Ta Hoang · 2000
Complex power quality disturbances are non-stationary and transient by nature and points of sharp variation such as singularities in transient signals usually carry the most important information about the disturbances. It is well known that wavelet transform modulus maxima (WTMM) of a signal using a wavelet that is the first derivative of a smoothing function, give a reliable multiscale representation of the signal. In this paper, we demonstrate how the WTMM representation may be used to detect the power transient disturbances and to extract their characteristic features for subsequent disturbance identification, and show that the quadratic spline wavelet performs better than the D4 wavelet. We also show that since the quadratic spline wavelet possesses the necessary requirements to be suitable for WTMM analysis, and in comparison to the D4 wavelet it is more compact, less susceptible to interference from surrounding noise, and has a better time resolution.