Complex frequency domain interpolation frequency estimation method considering white noise and harmonic effects
In the power system,frequency estimation is inevitably affected by noise and harmonics,so accuracy is limited.The Fourier Transform is a common tool for frequency estimation,but it has a problem of spectrum leakage,especially the long-range leakage caused by negative spectrum,which makes it is difficult to achieve accurate frequency estimation in a short time.In this paper,a complex frequency domain interpolation DFT frequency estimation method based on rectangular window is proposed.Besides,the theoretical variance model of frequency estimator under the influence of noise is established,and the correctness of the variance model is verified by simulation.This algorithm considers the long-range leakage effect caused by the negative spectrum,so it still has a high frequency estimation accuracy when the length of the measurement window is less than 2 fundamental wave cycles.Simulation and experiments show that in the presence of noise and harmonics,even the measurement window is short,the frequency estimation performance of this algorithm is better than the existing frequency estimation algorithms.
frequency measurementFourier transformnoiseharmonics
万方数据
维普
