Discrete Wavelet transform technique application in identification of power quality disturbances

Abstract

Poor power quality may cause many problems for affected loads, such as malfunctions, instabilities, short equipment lifetime, and so on. Poor quality electric power is normally caused by power-line disturbances, such as lightning impulses, interruption, voltage swell, voltage sag, harmonic distortion, flicker, resulting in failures of end-user equipment. In order to improve power quality, the sources and causes of such disturbances should be identified and localized before appropriate mitigating actions can be taken. In the paper the Discrete Wavelet Transform (DWT) Technique with Multiresolution Analysis (MRA) is used to classify various power disturbance types simulated with the help of Alternative Transient Program- ElectroMagnetic Transient Program (ATP-EMTP). The analysis conducted and results obtained show the merit of method in use and prospective application of wavelet technique to power disturbances assessment.