EPE Association: EPE 2025 - LS2e: Magnetic Components

EPE 2025 - LS2e: Magnetic Components - Inductors and Transformers
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2025 - Conference > EPE 2025 - Topic 08: Components linked to Power Electronics > EPE 2025 - LS2e: Magnetic Components - Inductors and Transformers

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   A Novel Optimization Method for Accurate AC resistance prediction of High Frequency Transformer
By Sobhi BARG, Souhaib BARG, Kent BERTILSSON [View]
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Abstract: Existing methods for high frequency design have two main limitations which significantly affect the design accuracy: (1) the choice of the suitable filling factor and (2) the inaccurate prediction of the Ac resistance. This paper proposes a novel numerical method to determine an accurate estimation of the Ac resistance and avoid the need of using the filling factor in the design process. The performed experimental results are in good agreement with the developed theoretical results. The study shows that the variation of the optimal B is the inverse of the root-mean-square core volume variation.

   Inductive, Capacitive and Resistive Aspects Modeling of Planar Windings Applied to a 1MHz LLC Converter
By Oussama DIHANE, Daniel SADARNAC, Tanguy PHULPIN, Éric LABOURÉ, Alain GASCHER, Lingeshwaren SOBRAYEN [View]
[Download]

Abstract: Planar transformers and inductors are subject to parasitic capacitances that can alter the operation of the converter using them. This article integrates capacitive aspects into conventional inductive and resistive modeling developed by Dowell. This leads to a relatively simple software program that enables fast simulation of planar components' frequency behavior, predicts conductors' current distribution, and deducts the resulting losses. Finally, an application example is proposed consisting of optimizing the design of a transformer by adjusting its windings, the nature of its materials, and the position of an air gap, to minimize current oscillations in the converter that could result from excessive parasitic capacitors.

   Modelling of Nanocrystalline Common-Mode Chokes with Custom Shape by Simulation-Based Extraction of Effective Permeability
By Herbert HACKL, Werner KONRAD, Martin STOIBER, Christian RIENER, Bernhard AUINGER, Martin HEINISCH [View]
[Download]

Abstract: Knowing the complex relative permeability of a ferrite or nanocrystalline core material is crucial to predict the insertion impedance of common-mode chokes. In practice, however, the material properties are often not known across the full desired frequency range. Additionally, factors like core shape, lamination and strip thickness influence the effective permeability and consequently the choke's impedance behaviour. This paper presents a workflow to create core material models that can be used in electromagnetic simulations to estimate the impedance behaviour of common-mode chokes. The core's material characteristics are determined by iteratively fitting model parameters to an impedance measurement using a generic laboratory setup. The resulting core model is then employed to predict the impedance of a common-mode choke in the intended application.

EPE 2025 - LS2e: Magnetic Components - Inductors and Transformers
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2025 - Conference > EPE 2025 - Topic 08: Components linked to Power Electronics > EPE 2025 - LS2e: Magnetic Components - Inductors and Transformers
	[return to parent folder]

	A Novel Optimization Method for Accurate AC resistance prediction of High Frequency Transformer By Sobhi BARG, Souhaib BARG, Kent BERTILSSON	[View] [Download]
Abstract: Existing methods for high frequency design have two main limitations which significantly affect the design accuracy: (1) the choice of the suitable filling factor and (2) the inaccurate prediction of the Ac resistance. This paper proposes a novel numerical method to determine an accurate estimation of the Ac resistance and avoid the need of using the filling factor in the design process. The performed experimental results are in good agreement with the developed theoretical results. The study shows that the variation of the optimal B is the inverse of the root-mean-square core volume variation.

	Inductive, Capacitive and Resistive Aspects Modeling of Planar Windings Applied to a 1MHz LLC Converter By Oussama DIHANE, Daniel SADARNAC, Tanguy PHULPIN, Éric LABOURÉ, Alain GASCHER, Lingeshwaren SOBRAYEN	[View] [Download]
Abstract: Planar transformers and inductors are subject to parasitic capacitances that can alter the operation of the converter using them. This article integrates capacitive aspects into conventional inductive and resistive modeling developed by Dowell. This leads to a relatively simple software program that enables fast simulation of planar components' frequency behavior, predicts conductors' current distribution, and deducts the resulting losses. Finally, an application example is proposed consisting of optimizing the design of a transformer by adjusting its windings, the nature of its materials, and the position of an air gap, to minimize current oscillations in the converter that could result from excessive parasitic capacitors.

	Modelling of Nanocrystalline Common-Mode Chokes with Custom Shape by Simulation-Based Extraction of Effective Permeability By Herbert HACKL, Werner KONRAD, Martin STOIBER, Christian RIENER, Bernhard AUINGER, Martin HEINISCH	[View] [Download]
Abstract: Knowing the complex relative permeability of a ferrite or nanocrystalline core material is crucial to predict the insertion impedance of common-mode chokes. In practice, however, the material properties are often not known across the full desired frequency range. Additionally, factors like core shape, lamination and strip thickness influence the effective permeability and consequently the choke's impedance behaviour. This paper presents a workflow to create core material models that can be used in electromagnetic simulations to estimate the impedance behaviour of common-mode chokes. The core's material characteristics are determined by iteratively fitting model parameters to an impedance measurement using a generic laboratory setup. The resulting core model is then employed to predict the impedance of a common-mode choke in the intended application.