Kalman filtering based approach for spectral analysis of power signals

In this paper, a spectral decomposition based method for interharmonics analysis is proposed for power systems where the fundamental frequency deviates significantly. In the proposed method, the spectral components of the voltage waveform are obtained by Kalman filtering. The method provides the fundamental frequency and the correct spectrum of the voltage waveform, and hence the exact interharmonics are obtained. The proposed method is tested with both simulated and field data obtained from a power system, where the fundamental frequency deviation is significant. The most important advantage of the proposed method is that since the interharmonic frequencies are obtained by Kalman filtering, no leakage effect of the DFT based approaches is observed in the proposed method.