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

Magnetic devices are used in the majority of power electronic applications, e.g. power electronic converters, mains filters or burst/surge protection. Typically, they are the bulkiest and most cost-intensive components. Flux interaction of differently aligned magnetic fields in inductors and transformers can be one opportunity for size and cost reduction. It enables controllable magnetic devices through an additional manipulated variable to improve application design. The presented article gives an overview about different methods of flux interaction of magnetic fields, their background, potentials and open research questions. The focus lies on electrically controlled magnetic devices, realized by auxiliary windings wound on or introduced into the magnetic core to control its saturation and the inductive behavior of the device by injecting a current. However, the given methods and explanations are transferable to magnetic devices influenced by permanent magnets. The background of the different flux interaction methods are explained theoretically and verified by simulations and several laboratory prototypes. The focus of the simulations and experimental investigations lies on magnetic devices for power electronic converters, whereby especially ferrite core materials were used.