A ferromagnetic based variable inductor analysis and design methodology

Extended ZVS/ZCS operation of Class-E Inverter for Capacitive Wireless Power Transfer

“…However, its manufacturing is not simple, resulting in higher costs. For this reason, the most used approaches consist of changing the magnetic permeability of the material using an additional magnetic polarization flux in addition to the main inductor magnetic flux, shifting the magnetic induction [31]. This approach has been widely used to control LLC converter [32]- [37].…”

Review of Flux Interaction of Differently Aligned Magnetic Fields in Inductors and Transformers

“…Especially during the last decade, many investigations on parallel biasing were made, e. g. to reduce the size of the magnetic core or to improve its geometry, as it is shown in [18] and [19]. References [20] and [21] present investigations on magnetic flux optimization in variable inductors. The auxiliary bias winding is not on the main EE core geometry but applied on an additional E core, which is stacked under the main core.…”

Experimental analysis of a DC current-controlled variable inductor in a DC-DC converter

“…Common applications for this device are: reactive power control [9], LED lighting and correspondent driver's control [7], [8], [10], [11], power factor correction [12] and current ripple reduction [13]. Laboratory experiments with VIs have been done with different magnetic core designs, in particular the double E [11], [12], [14], triple E [8] and toroid core design [3], [6], [13], [15]. The research done on the double toroid type has not explained its behaviour for different power levels.…”