Wavelet transform based fuzzy inference system for power quality classification

Abstract

The paper presents a hybrid scheme using a Discrete Wavelet Transform and a Fuzzy Expert System for feature extraction and classification. The signal under test (electrical current or voltage for Power Quality study) is processed through a DWT decomposition block to generate the feature extraction curve. The DWT Level and Energy information from the feature extraction curve is then passed through a diagnostic module that computes the truth-value of the signal combination and determines the class to which the signal belongs. The proposed scheme is much simpler and powerful than currently available PQ classification schemes. © Springer-Verlag Berlin Heidelberg 2002.