Flexible Time-Delay Designs for Harmonic Sequence Filter/Extraction: A Further Generalization of Two-Sample Methods

Time-delay is an inevitable operator causing slow dynamic response of related systems employing harmonic sequence (HS) filters/extractors. This letter presents a new concept of flexible time-delay designs as a further generalization of two-sample methods (i.e., delayed signal cancellation) to improve the dynamic response and robustness of HS filters/extractors. The new concept offers flexible designs of filters/extractors to improve both the steady-state quality and dynamic response of filter/extraction stages. Comparative experimental results show significant improvements in filtering performance regarding fast dynamic response, small steady-state errors, improved robustness, and flexible designs to filter implicit harmonic sidebands. These feasibilities are especially beneficial for applications in power systems and power electronics with the available information on harmonic sidebands.