Voltage sag analysis through wavelet transform

The objective of the paper is an in-depth voltage sag characterization. Attention is turned in particular to detect the frequency range associated to the main transients contained in the voltage waveform during sag. A suitable tool for this study is the wavelet transform, which allows decomposition of a transient signal into a series of wavelet components, each being a time domain signal that covers a specific frequency band. Different actual voltage sags are analyzed through the wavelet transform and the results compared and commented upon.