On some advanced methods for waveform distortion assessment in presence of interharmonics

One of the main problems for waveform distortion assessment that is to reduce the effects of the spectral leakage due to fundamental and harmonics on interharmonic components. In the framework of DFT approaches, line frequency synchronization techniques or algorithms to compensate desynchronization are necessary; alternative approaches as those based on the Prony methods are not sensitive at all to desynchronization but can require not negligible computation burden. In the paper, different proposals by the same authors regarding both DFT based and Prony based advanced methods are recalled and compared to each other. The results of several numerical experiments are reported and analyzed; some of them are in accordance with IEC guidelines and some others are related to more open scenarios