Research On Wavelet Transform In Power Harmonic Detection

In recent years, power electronics and nonlinear equipment are widely used in electricpower system. Then brought a large number of dynamic nonlinear load in power gridvoltage waveform distortion and other power quality problems. The phenomenon of powerharmonic detection research gradually become one of the important research subject inmodern power system. At the same time, it has become the focus of power grid companiesand power customers. In this paper, on the basis of summarizing the existing harmonicanalysis methods, Learn what experience and put forward the oneself to the improvementof the algorithm, Adopt the method of wavelet transform for harmonic detection. Usingthe MATLAB software simulation of a typical signal, verify the feasibility of this method.First, the article describes the phenomenon of power harmonic, harmoniccharacteristics, reasons and its harm, and so on.Introduces the various interference sourcesof power quality. Analysis compares the fast Fourier transform, discrete Fourier, addwindow Fourier transform, discrete wavelet transform and continuous wavelet transformand so on several important transform method, Discusses the characteristics and applicablescope of each theory.Second, for the particularity of the power system harmonic signal, this paper usewavelet has time-frequency domain localization properties, This mathematical processingmethod using wavelet analysis, By modulus maxima representation of signal singularity,Give the modulus maxima in the strange place，Through the simulation of the harmonicsignals，Using simulation software to detect harmonic generation time and harmonic, andso on and so forth.Third, the article made a summary about the key contents, put forward the need tocontinue to improve And looking to the further study of this problem.