A Power-Loss-Dependent Inductance Model for Ferrite-Core Power Inductors in Switch-Mode Power Supplies

This paper proposes a new modeling approach for ferrite-core (FC) power inductors used in switch-mode power supplies (SMPSs). In particular, a novel power-loss-dependent inductance behavioral model is proposed, whose parameters can be identified through a limited set of proper experimental measurements of inductor current and voltage. Unlike conventional thermal modeling approaches, which require information on core temperature, the proposed behavioral model relies only on easily measurable quantities. The model is also suitable for being implemented in circuit simulators. By comparing PSIM simulations and experimental measurements on a buck converter for commercial FC inductors, we show that the model allows a reliable prediction of the steady-state inductor current, under different SMPS working conditions.