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High-frequency and high-power density converters are essential for many applications such as automotive and more electric aircraft. To improve power density, planar magnetic components are increasingly used in power electronic converters owing to their advantages, such as less high-frequency losses, repeatability, and better thermal performance compared to conventional wound components. Considerable attention has been paid to their electrical performance. However, the thermal aspects are essential for enhancing completely their performance. Currently, there is an increasing interest in these critical aspects of high-density power converters. This paper presents a literature review of studies on the thermal modeling of planar magnetics. The papers were organized according to the model type and analyzed to highlight their merits and limitations. A multicriteria comparison of the studied papers was performed. Moreover, the key points and issues related to the thermal modeling are addressed to guide designers in enhancing the thermal aspects of planar magnetic components.

The leakage inductance of high-frequency (HF) transformer is a key parameter to help improve the power density of isolated DC/DC converters. Minimized, it can reduce the losses, but maximized or precisely tuned, the leakage inductance can intervene in the converter operation, avoiding supplementary HF inductor. This is the case for soft-switching converters or specific topologies like dual active bridge for example. The present work aims to adjust the value of a planar transformer (PT) leakage inductance, acting on the positioning of the conductors within the PT winding window. The methodology developed here is based on finite element analysis (FEA) simulation as well as single and multi-objective optimizations to adjust the value of the leakage inductance while minimizing the AC resistance. The optimization is carried out for different interleavings, questioning the usual choices of interleavings known to minimize or maximize the leakage inductance.

L’inductance de fuite est un paramètre essentiel des transformateurs HF dans les convertisseurs DC/DC isolés. Avec l’utilisation de la technologie planar et des enroulements en PCB, ce paramètre peut être réglé à une valeur prédéterminée en ajustant le positionnement des conducteurs dans la fenêtre des transformateurs. Cet article présente une étude autour de la minimisation, de la maximisation et du réglage de l’inductance de fuite d’un transformateur planar. La méthodologie développée est basée sur des simulations par éléments finis (FEM) couplées avec un algorithme d’optimisation multi-objectifs qui permettent de régler une inductance à une valeur donnée, tout en minimisant les pertes cuivre induites.