Study On The Analysis Method Of Harmonic In Power Grid

In the modern industrial society, electricity is a kind of energy widely used. With the development of the society, the quality of the electricity is required higher. Because of all kinds of nonlinear equipment to be used in the power system, especially power electronic devices, it will lead to current and voltage distortion. Therefore, government has pay more attention to harmonic governance, harmonic is one of the main hazards of power grid, it caused the energy waste and hinder the development of the national economy, so it is very important to calculate the harmonic parameters for harmonic governance.This paper describes the research background and significance of harmonic, and describes the definition, source and harm of harmonic briefly. It analyzed the deficiency of Fourier transformation in harmonic analysis and spectrum aliasing, spectrum leakage and fence effect. It put forward the choice of window function principle in the improved FFT algorithm. I has been studied the accuracy of harmonic parameters based on Fourier transformation.This paper analyzes the characteristics of the commonly used window function, it proposed and established triangular self-convolution window. It proposes spectrum interpolation on harmonic analysis based on triangular self-convolution window. It analyzes the characteristics of the commonly used cosine window function,it proposed and established Hanning self-convolution window,it proposes new correction algorithm of discrete discrete phase spectrum difference on harmonic analysis based on Hanning self-convolution window.At last by the simulation it analysises the given harmonic signal based on proposed window and interpolation algorithm. According to the results of harmonic anslysis,it can get the disadvantage and advantage of various algorithms...