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.

Recent studies have proved that sustainable saturation operation of Ferrite Power Inductors (FPIs) allows reducing the inductor size and increasing the power density in Switch-Mode Power Supply (SMPS) applications. This paper discusses a new behavioral model for reliable prediction of ac power loss in FPIs, including the effects of saturation. The new model has been identified by means of the Genetic Programming (GP) algorithm combined with a Multi-Objective Optimization (MOO) technique, starting from large sets of power loss experimental measurements. The proposed ac power loss model uses as input variables the voltage and switching frequency imposed to the inductor by the SMPS operation, while the dc inductor current is used as a parameter expressing the impact of saturation. Such quantities can be easily determined for whatever converter topology and in real-world switching operation, thus confirming the readiness and the easiness-to-use of the proposed behavioral model. The results of experimental tests presented in this paper prove the reliability of the power loss predictions, also by correctly accounting for the impact of inductors saturation.

This paper revisits the behavioral modeling of inductors used for Switch-Mode Power Supply (SMPS) design. A novel unified behavioral modeling for power inductors is herein proposed, which considers the DC current passing through the device and the equivalent applied voltage and switching frequency as model inputs, and the resulting peak-to-peak current ripple, total power loss and temperature as model outputs. The proposed behavioral modeling relies on simple analytical formulas, discovered from experimental measurements by using a multi-objective evolutionary algorithm. The resulting behavioral models allow to define the ``Constrained Operating Area'' of a power inductor, which describes the boundary area in the three-dimensional domain of switching frequency, DC current and equivalent voltage that can be applied to the component while maintaining its peak-to-peak current ripple, power loss and temperature within given limits. The experimental case studies presented in the paper eventually confirm the reliability of the proposed behavioral modeling approach and of the resulting models, in the assessment of the suitability of a given inductor and in the comparative evaluation among different inductors for a given SMPS application.

This paper proposes a system-level approach suitable to analyze the performance of a dynamic Wireless Power Transfer System (WPTS) for electric vehicles, accounting for the uncertainty in the vehicle trajectory. The key-point of the approach is the use of an analytical behavioral model that relates mutual inductance between the coil pair to their relative positions along the actual vehicle trajectory. The behavioral model is derived from a limited training data set of simulations, by using a multi-objective genetic programming algorithm, and is validated against experimental data, taken from a real dynamic WPTS. This approach avoids the massive use of computationally expensive 3D finite element simulations, that would be required if this analysis were performed by means of look-up tables. This analytical model is here embedded into a system-level circuital model of the entire WPTS, thus allowing a fast and accurate analysis of the sensitivity of the performance as the actual vehicle trajectory deviates from the nominal one. The system-level analysis is eventually performed to assess the sensitivity of the power and efficiency of the WPTS to the vehicle misalignment from the nominal trajectory during the dynamic charging process.

This paper analyzes and discusses Peak-Current Mode Control (PCMC) in DC-DC voltage regulators using power inductors subjected to saturation. It is proved that the impact of inductors saturation on the operation of the PCMC regulators can be reliably predicted by means of the proposed mathematical model and technique. The results of circuit simulations and experimental measurements, regarding a DC-DC boost regulator, validate the theoretical analysis and the proposed model. The results confirm that the use of saturable inductors is a viable and reliable solution for PCMC regulators, and demystify some concerns about the saturable inductors behavior in presence of line/load transients and overloads.