ABOUT THE EVALUATION ERRORS OF SIGNAL PARAMETERS BY USING FFT

摘要

The signal's amplitude and phase measurement by acquisition systems and FFT transform can be subject of uncontrolled errors because of intrinsic properties of Fourier Transform. The paper proposes a correction method based on the best evaluation of the fundamental frequency and calculation of the fundamental RMS for voltage and current as well as their phase by using the definitions of these quantities. To validate the method virtual experiments on generated signals and laboratory measurements were made. There is a very good agreement of measurements and calculated values.