An Effective Harmonic Parameters Estimation Algorithm Based on Transformed FFT Sequence

In the practical harmonic analysis, the classical windowed interpolation methods usually have low estimation accuracy and high implementation complexity. Based on the analysis of attenuation characteristics of the fast Fourier transform (FFT) sequence, a novel harmonic analysis method with high precision by using a simple transformation is introduced. Our algorithm performs a simple transformation on the original FFT sequence, which reduces the interference among different spectral lines, and thus effectively suppresses the spectrum leakage. Based on this, the estimation formulas for the amplitude and phase are derived. The simulation results show that the proposed algorithm can effectively improve the accuracy of parameter estimation. In addition, compared with the classical windowed interpolation methods, the new method has lower computation complexity.