Estimation of the Component Parameters for the Evaluation of the Power Quality Disturbances in the Frequency Domain

Simple algorithms for fast measurement and estimation of the unknown changing frequency, amplitude, phase, and other parameters for evaluation of the power quality disturbances are presented. Parameters are calculated from the DFT coefficients. The optimum for reducing the time of measurement (three periods of the fundamental component) and reducing the influences of the harmonic components can be the estimation with the three-point interpolation and the Hanning window.