Identification of power quality disturbances using the MATLAB wavelet transform toolbox

This paper presents an approach that is ab le to
provide the detection and location in time as well as the
identification of power quality problems present in both
transient and steady-stable signals. The method was
developed by using the discrete wavelet transform (DWT)
analysis. The given signal is decomposed through wavelet
transform and any change on the smoothness of the
signal is detected at the finer wavelet transform
resolution levels. Later, the energy curve of the given
signal is evaluated and a relationship between this energy
curve and the one of the corresponding fundamental
component is established. The paper shows that each
power quality disturbance has unique deviations from the
pure sinusoidal waveform and this is adopted to provide
a reliable classification of the type of disturbance.