Harmonic Analysis Method Based on ZoomFFT and Multispectral Interpolation Algorithm

Various detection algorithms based on fast Fourier transform have become a common method for power quality analysis due to their fast response speed and easy engineering implementation. It is easy to cause spectrum leakage, and difficult to accurately realize the separation and detection of multiple harmonics. A complex harmonic detection method based on the Blackman-Harris window function quadratic line interpolation algorithm and the complex modulation spectrum refinement algorithm is proposed. The improved windowed interpolation algorithm is used to detect harmonics. For the spectrum where main lobe interference occurs, the complex modulation spectrum refinement algorithm is used to analyze the harmonics accurately. The simulation results show that the method can distinguish similar harmonic components, has strong real-time performance, and can meet the needs of power system detection of power parameters.