• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.1
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• pp.16-23
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• 2004

Permanent magnet-excited transverse flux linear motor(TFLM) is known to have more excellent ratio of force to weight than any other linear motors. But, thrust generated by phase current is non-linear with regard to current and relative position like switched reluctance motor. This makes current and speed controller design difficult. This paper presents a method on minimization of thrust ripple of permanent magnet-excited transverse flux linear motor. Using genetic algorithm(GA), optimal current waveform can be found under the constraint conditions such as current limit, minimum of ohmic loss and limited rate of change of current etc. The effectiveness is verified through computer simulation and experimental test results.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.33-35
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• 2002

This paper proposes the optimal design method to reduce the cogging torque of the interior permanent magnet motor using the design of experiment. The slot opening. tooth tips and the pole arc/pole pitch are chosen as factors of the design of experiment in order to find optimal conditions of the interior permanent magnet motor. Finally, the cogging torque of the optimized motor compares with that of the original motor.

• Journal of Magnetics
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• v.18 no.2
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• pp.125-129
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• 2013

This paper deals with a water-cooled direct drive permanent magnet (DD-PM) motor design for an injection-molding application. In order to meet the requirements for the target application and consider the practical problems of the manufacturing industry, the DD-PM motor is designed in consideration of efficiency and structural strength with many constraints. The performances of the designed motor are estimated not only by magnetic field analysis, but also by thermal and structural analysis. The design and analysis results are presented with experiment results.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1667-1672
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• 2009

The spherical motor is an electric machine which is able to tilt its shaft on 3-dimensional space as using electromagnetic force. Recently a permanent magnet is remarkable material for applying electric machinery, because of high magnetic flux density. In this paper, a spherical motor, which has permanent magnet on its rotor, is researched. As known, the spherical motor has a special feature as 3 degrees of freedom (D.O.F) operation. This performance can be realized by using electromagnetic torque between coils and magnets. Therefore, in this paper, a permanent magnet spherical wheel motor is introduced and performance characteristics are analyzed for improving of operation stability.

• Journal of Magnetics
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• v.6 no.3
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• pp.101-107
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• 2001

A model to describe the effect of stator slotting in the airgap region of a linear brushless permanent magnet motor (LBLPMM) is proposed for analytical prediction of magnetic field distribution. It is a two-dimensional model based on superposition of the effect of stator slotting and main field due to permanent magnet (PM) without stator slotting. The effect of stator slotting is expressed in form of a generalized equation, which is obtained by numerical analysis and is a function of motor geometric parameters, so the proposed model effectively accounts for the effect of stator slotting in the airgap field distribution according to change of motor geometry or relative motion of stator and armature. Results of prediction from the proposed model are compared with corresponding finite element analysis.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1027-1028
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• 2007

In this paper, the variation of air-gap field intensity caused by the slot-opening in interior permanent magnet (IPM) motor is investigated, which is for predicting the instantaneous magnetic field more preciously in analytical method further. It is different with the approach of dealing the slot-opening effect on the air-gap field distribution with the "relative permeance" function in surface permanent magnet (SPM) motor. The prediction of the air-gap field in IPM motor is much more complex than SPM motor. In this study, an approximate estimation method is adopted based on analyzing the changing of flux path in both the IPM rotor part and stator part, and in additional an analytical function defined as "relative pole-arc" is built. The finite element method(FEM) is used for confirming the slot-opening effect on the field prediction.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1174-1176
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• 2005

The permanent magnet(PM) overhang effect has been generally used to enhance the linkage flux in the motor. In this paper, we quantitatively investigate the PM overhang effect in the new type axial flux permanent magnet(AFPM) motor with a double-sided airgap. The motor performances such as linkage flux, back electromotive force(EMF), magnetic force, etc. were analyzed according to the variation of the overhang angle. From the results, we can select the proper overhang angle of PM which improves the performance of the AFPM motor.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.768_769
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• 2009

Average torque of PMa-SynRM(Permanent Magnet-assisted Synchronous Reluctance Motor) is changed by magnet form inserted to the barrier. Because the magnet form influences to the magnet-torque and reluctance torque. Therefore, this paper present a suitable permanent magnet form design for maximum torque when the magnet quantites are always fixed. And each motor characteristic such as average torque, torque ripple, cogging torque and back-EMF are analyzed by FEM(Finite Element Method) for optimal design..

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1832-1837
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• 2011

This paper presents the optimal permanent magnet shape on the rotor of an interior permanent magnet motor to reduce the core losses and improve the performance. As permanent magnet has conductivity inherently, it causes huge amount of eddy current losses by the slot harmonics with concentrated winding. This loss is roughly 100 times larger than that of distributed winding in high speed operation and it cannot be ignored, especially on traction motors. Each eddy current loss on permanent magnet has been investigated in detail by using FEM(Finite Element Method) instead of EMCNM(Equivalent Magnetic Circuit Network Method) in order to consider saturation and non-linear magnetic property. Simulation-based DOE(Design Of Experiment) is also applied to avoid large number of analyses according to each design parameter and consider expected interactions among parameters. Consequently, the optimal design to reduce the core loss on the permanent magnet while maintaining or improving motor performance is proposed by an optimization algorithm using regression equation derived and lastly, the core loss reduction on the proposed shape of the permanent magnet is verified by FEM.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.04a
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• pp.720-725
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• 2000

This paper persents the characteristic analysis method of slotless-type Permanent Magnet Synchronous Motor using the analytical method. The results of analysis are compered with FEM to verify the validity of the proposed method.