Comparison of Eddy Current Loss Calculation Techniques for Axial Flux Motors with Printed Circuit Board Windings

In slotless machines, the winding conductors are exposed to the magnetic air gap field, which causes additional eddy current losses, thus decreasing efficiency and affecting thermal utilization. This is the case, inter alia, for axial flux motors equipped with printed circuit board windings, where t...

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Main Authors: Andreas Bauer, Daniel Dieterich, Sven Urschel
Format: Article
Language:English
Published: MDPI AG 2025-05-01
Series:Energies
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Online Access:https://www.mdpi.com/1996-1073/18/10/2603
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author Andreas Bauer
Daniel Dieterich
Sven Urschel
author_facet Andreas Bauer
Daniel Dieterich
Sven Urschel
author_sort Andreas Bauer
collection DOAJ
description In slotless machines, the winding conductors are exposed to the magnetic air gap field, which causes additional eddy current losses, thus decreasing efficiency and affecting thermal utilization. This is the case, inter alia, for axial flux motors equipped with printed circuit board windings, where the winding is made of copper–fiberglass epoxy laminations and located in the air gap. The dominant influencing factors are primarily the width of the conducting tracks and the magnetic air gap flux density and frequency. The evaluation time is a crucial constraint when calculating thousands of different designs for design space exploration or performing multi-objective optimizations. Finite element simulations can achieve very precise results, but unlike semi-analytical approximation functions, they are very time-consuming and therefore not the method of choice for design space exploration. This publication provides a comprehensive overview of a selection of different eddy current loss calculation techniques that are applicable for rectangular tracks and round wire windings. A comparison of the calculated results for a finite element simulation is presented for a slotless axial flux machine with printed circuit board windings and rectangular tracks. The calculation time consumed is also compared. The current density distribution of planar conductors of air gap windings differs from that in electrical steel sheets. In contrast to the methods based on steel sheets, only the adapted methods for conductors in air gaps offer acceptable accuracy. A recommendation is provided for the method that offers the best balance between accuracy and computation time for the early-stage design of slotless axial flux machines.
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spelling doaj-art-32dec6dbb0304b449ed927602f40fed52025-08-20T02:33:55ZengMDPI AGEnergies1996-10732025-05-011810260310.3390/en18102603Comparison of Eddy Current Loss Calculation Techniques for Axial Flux Motors with Printed Circuit Board WindingsAndreas Bauer0Daniel Dieterich1Sven Urschel2Electrotechnical Systems of Mechatronics, Kaiserslautern University of Applied Sciences, Schoenstraße 11, 67659 Kaiserslautern, GermanyElectrotechnical Systems of Mechatronics, Kaiserslautern University of Applied Sciences, Schoenstraße 11, 67659 Kaiserslautern, GermanyElectrotechnical Systems of Mechatronics, Kaiserslautern University of Applied Sciences, Schoenstraße 11, 67659 Kaiserslautern, GermanyIn slotless machines, the winding conductors are exposed to the magnetic air gap field, which causes additional eddy current losses, thus decreasing efficiency and affecting thermal utilization. This is the case, inter alia, for axial flux motors equipped with printed circuit board windings, where the winding is made of copper–fiberglass epoxy laminations and located in the air gap. The dominant influencing factors are primarily the width of the conducting tracks and the magnetic air gap flux density and frequency. The evaluation time is a crucial constraint when calculating thousands of different designs for design space exploration or performing multi-objective optimizations. Finite element simulations can achieve very precise results, but unlike semi-analytical approximation functions, they are very time-consuming and therefore not the method of choice for design space exploration. This publication provides a comprehensive overview of a selection of different eddy current loss calculation techniques that are applicable for rectangular tracks and round wire windings. A comparison of the calculated results for a finite element simulation is presented for a slotless axial flux machine with printed circuit board windings and rectangular tracks. The calculation time consumed is also compared. The current density distribution of planar conductors of air gap windings differs from that in electrical steel sheets. In contrast to the methods based on steel sheets, only the adapted methods for conductors in air gaps offer acceptable accuracy. A recommendation is provided for the method that offers the best balance between accuracy and computation time for the early-stage design of slotless axial flux machines.https://www.mdpi.com/1996-1073/18/10/2603eddy current lossesPCB windingaxial flux machinemotor windingplanar windingslotless machine
spellingShingle Andreas Bauer
Daniel Dieterich
Sven Urschel
Comparison of Eddy Current Loss Calculation Techniques for Axial Flux Motors with Printed Circuit Board Windings
Energies
eddy current losses
PCB winding
axial flux machine
motor winding
planar winding
slotless machine
title Comparison of Eddy Current Loss Calculation Techniques for Axial Flux Motors with Printed Circuit Board Windings
title_full Comparison of Eddy Current Loss Calculation Techniques for Axial Flux Motors with Printed Circuit Board Windings
title_fullStr Comparison of Eddy Current Loss Calculation Techniques for Axial Flux Motors with Printed Circuit Board Windings
title_full_unstemmed Comparison of Eddy Current Loss Calculation Techniques for Axial Flux Motors with Printed Circuit Board Windings
title_short Comparison of Eddy Current Loss Calculation Techniques for Axial Flux Motors with Printed Circuit Board Windings
title_sort comparison of eddy current loss calculation techniques for axial flux motors with printed circuit board windings
topic eddy current losses
PCB winding
axial flux machine
motor winding
planar winding
slotless machine
url https://www.mdpi.com/1996-1073/18/10/2603
work_keys_str_mv AT andreasbauer comparisonofeddycurrentlosscalculationtechniquesforaxialfluxmotorswithprintedcircuitboardwindings
AT danieldieterich comparisonofeddycurrentlosscalculationtechniquesforaxialfluxmotorswithprintedcircuitboardwindings
AT svenurschel comparisonofeddycurrentlosscalculationtechniquesforaxialfluxmotorswithprintedcircuitboardwindings