On the Processing of Harmonics and Interharmonics: Using Hanning Window in Standard Framework

The harmonic and interharmonic analysis recommendations contained in the latest International Electrotechnical Commission (IEC) standards on power quality are considered. The spectral leakage problems due to synchronization errors of the analyzed waveforms with the window widths adopted are analyzed. Improvements of the signal processing recommended by the IEC, based on the utilization of the classical Hanning window in place of the rectangular window, are proposed and made compatible with the grouping technique introduced in the standards. Sensitivity analyses on simple case studies together with experimental results show the sensitivity of the signal processing recommended by the IEC to synchronization errors and the usefulness of the improvements proposed.