The Research On The Method Of Power Quality Disturbances Detection And Classification

In recent years, power quality has become a problem which attracts the concern in many fields. However, to enhance the power quality, it is the first thing to detect and classify the power quality disturbances and then take measures according to different ones. A method which uses dq transform and wavelet transform is put forward in this paper. It can detect and classify the familiar power quality disturbances effectively. According to different characteristics of dq transform and wavelet transform respectively, voltage sags, swells, interruptions, impulses, phase steps, frequency deviations and noise are detected and classified by dq transform, and wavelet transform is applied to classify oscillations and harmonics. Extensive studies by Matlab simulation evinced that, the accuracy of the method for oscillation and the other eight disturbances classification exceeds 95%, and it is over 91% when high frequency oscillation and low frequency oscillation are differentiated. The situation that more than one disturbances occur at the same time is discussed, and the validity and the accuracy of the method are very well.Zhang xiujuan(Electric power system and its automation )Directed by associate prof. Xu yonghai...