Suppression factor as evaluation criterion for wide‐frequency filtering equipment

Abstract

Here, a novel harmonic suppression performance criterion, namely suppression factor (SF), is suggested for the wide‐frequency power filtering equipment. Performances of single‐tuned passive filter, combination of passive filters tuned to various frequencies, shunt active power filter (APF), and a shunt hybrid active power filter (HAPF) topologies have been evaluated considering their SF values over a defined frequency range. Moreover, effect of the control method for the active filtering equipment on SF values is also analysed by comparing both theoretical and the experimental results. The frequency range of harmonics to be suppressed is chosen using the field measurements of Induction melting furnace (IMF) load, one of the most problematic loads in terms of interharmonics, and a field implemented HAPF system is used for the experimental verifications.