Determination of the roll-off value in the air-gapped inductor of a DC-DC boost converter circuit with FEA parametric simulations

Abstract
The electromagnetic behavior of the inductors used as passive circuit elements directly affects the electrical and mechanical performance of the power electronics circuits. In general, when using inductor core structures with or without airgap in the classical design process, the dynamic effects of the inductance value are not considered in the design stage. However, the inductance value may change during the operation of the circuit due to electrical and magnetic parameters of the inductor, and this change is called roll-off value of the inductance. In this study, the roll-off value has been measured graphically and numerically based on mechanical parameters (such as air-gap length) and electrical parameters (such as winding turns and DC current amplitude) for an air-gapped ferrite E core designed with FEA software. Thus, not only the inductance value calculated in the design stage but also the roll-off value during the operation of the circuit has been reported with the parametric simulation studies.