Estimation and Tracking of the Power Quality Disturbances in the Frequency Domain

In this paper, simple algorithms for fast measurement and estimation of the unknown changing frequency, amplitude, and phase difference of the sinusoidal signals from two channels with the same frequency, as well as other parameters for evaluation of the power quality disturbances, are presented. Parameters are calculated from the DFT coefficients around the component peaks. The improvement for reducing the influences of the harmonic components is the estimation with the three-point interpolation and the Hann window.