Waveforms from a power plant’s generator are analyzed wih Discrete Wavelet Transform (DWT). For the steady state case reference data were calculated (DWT characteristics, details and approximations vectors, RMS value and 3-D tables that can be used to determine faster, in an original way, the parameters of a harmonic distortion). An algorithm is proposed for the evaluation of medium-range unsteady state disturbances and for the recalculation of some indices that characterize the monitored signal (e.g. the correct RMS value, parameters of a harmonic distortion etc.).

Keywords: Discrete wavelet transform, Distorting regimes, Power quality