Design, Implementation, and Operation of a New C-Type 2nd Harmonic Filter for Electric Arc and Ladle Furnaces

Suppression of the Second Harmonic Subgroup Injected by an AC EAF: Design Considerations and Performance Estimation of a Shunt APF

“…The field measurements have shown that a well-designed conventional SVC can successfully bring the input power factor of an AC EAF installation to unity, minimize light flicker, and suppress low order integer harmonics except the second current harmonic component [1]. If the SVC system is equipped with a second harmonic passive shunt filter with a very sharp operating characteristic, this second HF topology leads to some operational problems and cannot suppress second harmonic subgroup [29] as reported in [9]. This is because interharmonic content of the line currents around the fundamental and the second harmonic components is rich and especially those around the second harmonic interact with the passive second HF resulting in the amplification of the second harmonic subgroup and group components.…”

“…), dominant interharmonics have been found out to be around the fundamental frequency up to the second harmonics [6,7]. Some suggestions to suppress those harmonic and interharmonic current components have already been made in the literature [8,9]. White et al [8] proposes the use of second and third passive harmonic filters (HF) in order to suppress the harmonic content of the AC EAF.…”

“…White et al [8] proposes the use of second and third passive harmonic filters (HF) in order to suppress the harmonic content of the AC EAF. Additionally, a C-type second HF has been suggested in [9] in order to eliminate the amplification of interharmonics due to passive harmonic filter resonances. However, since the operation characteristics of the AC EAF is rapidly changing during the steel melting process, a fast-responding resonant-free filter can be much more effective for the suppression of the harmonics and interharmonics of AC EAF.…”

Application of a C-Type Filter Based LCFL Output Filter to Shunt Active Power Filters

“…This paper proposes and designs an new output filter for application to a three phase three wire SAPF. This new output filter is derived from a traditional LCL filter by replacing its capacitor with a C-type filter [27]- [29]. Therefore, it has an L-C-type filter-L (LCFL) structure and has been named an LCFL filter.…”

“…It must be noted that the C-type filter adopted in the LCFL filter is not the same as that commonly referred to in the literature. Traditionally, C-type filters have been mainly used as independent passive power filters (PPFs) in industrial applications fields, such as iron and steel plants [27], HVDC projects [28], [29], and so on. There are also papers that discuss the applications of a C-type filter together with an APF [30]- [33].…”