Power Quality Disturbances Fuzzy Identification Based on DQ Conversion and Wavelet Energy Distribution

For the online monitoring and management of power quality, a power quality disturbances fuzzy identification method based on dq conversion and wavelet energy distribution is proposed. The method uses the characteristic of dq conversion valid values to identify voltage sag, swell and interruption. It uses wavelet multiresolution analysis for harmonics, flicker, oscillatory transient and pulse transient and calculates the energy distribution of every decomposition layer as a signal eigenvector. It implements their online identification through calculating the fuzzy nearness between the energy distribution of the measured signal and the eigenvector. The simulation results show that the method possesses the features of high accuracy rate of the identification, fast response, simple structure and strong resistance to noises.