• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.4
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• pp.379-382
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• 2014

In this paper, the cogging torques were calculated for 1kw double-sided axial flux permanent magnet (AFPM) generator with different stator core pole arrangements. The generator is composed of 18 stator pole and 24 rotating field magnets on each side. The cogging torques of the generator with three types of arrangements of stator poles were calculated using 3D finite element method and the optimum core shape was determined to minimize the cogging torque.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.86-88
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• 2004

In this paper, optimal stator slot shape of 3-phase inverter-fed induction motor is designed to reduce stator core and winding losses. For the analysis, the F.E.M on 1 phase band periodic condition in stator is coupled with harmonic equivalent circuit. For the optimal design, the conjugate gradient method is used as an optimizing algorithm. The stator core and winding losses are reduced by the design method. The results are verified by those of the time-step finite element analysis.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2013-2018
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• 2014

According to the manufacturing process of the laminated stator core for an inserted permanent magnet synchronous motor (IPMSM), the iron loss may be different. It is because the mechanical stress imposed to electrical steel sheet is strongly dependent on the manufacturing process. This paper proposes a new iron loss measurement algorithm which utilizes the induced voltage of a search coil and exciting current. The method is effective even when the distribution of magnetic flux density is not uniform along the magnetic flux path as well as uniform. The developed iron loss measurement system is applied to bonded- and embossed-type segmented stator cores of an IPMSM, and the iron losses are quantitatively compared.

• Journal of Electrical Engineering and Technology
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• v.6 no.3
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• pp.350-355
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• 2011

This paper deals with the comparison of magnetic characteristics in transverse flux rotary machine according to different stator core composition with the same rotor. Three different stator designs are considered in the analysis according to the material composition of inner and outer stator cores. Electromotive force (EMF), inductance, torque, and core losses are calculated by threedimensional finite element analysis. Calculated and measured results of back-EMF according to the analysis models in dependency on speed are presented.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.2
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• pp.76-82
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• 2006

This paper investigates the magnetic field behavior and its iron losses in the stator core using electrical steels. The analysis model is a brushless motor with the permanent magnet. The elliptical rotating and alternating flux distributions with non-sinusoidal waveform are obtained by Finite Element Method and then their harmonic components are extracted. Based on these results, the local iron losses in the stator core caused by the harmonic flux are calculated. And then this paper explains the relation between flux waveform and iron loss produced in each part of the stator core. Furthermore, the iron loss at no load condition is measured and compared with the analysis results.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1089-1090
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• 2011

This paper presents a novel two-phase two-pole permanent magnet synchronous motor (PMSM) with asymmetric U-core stator structure. The construction and parameters of the novel two-phase U-core PMSM are compared with a conventional U-core single-phase PMSM (SPMSM). Then transient characteristics such as torque, back-emf, and power loss of the both PMSMs are analyzed by using 3-D Finite Element Method (FEM). Under the same condition of rated input current, synchronous speed, similar dimensions and volume, FE results show that the two-phase PMSM with U-core stator has significantly less torque ripple than single-phase U-core PMSM, with similar power loss and efficiency.

• Journal of Magnetics
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• v.17 no.1
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• pp.51-55
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• 2012

This paper presents an eddy current loss analysis for a transverse flux rotary machine (TFRM) with laminated stator cores, which consist of inner and outer cores whose laminated directions are perpendicular to each other. Although the TFRM is laminated to reduce eddy current losses, it still exhibits rapidly increasing core losses as the frequency increases. To solve this problem, slits are introduced to the stator outer core. 3-dimensional finite element analysis (3D FEA) based on the T-${\Omega}$ formulation is used to solve the eddy-current problem for a various numbers of slits in the nonlinear lamination core. The effects of the slits are confirmed using experiment data and 3D FEA results.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.1044-1048
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• 2002

The experimental modal testing has been carried out for the stator of a generator to confirm the vibrational mode shapes and the corresponding natural frequencies. The model of the stator for the vibration analysis was developed and a series of vibration analyses was carried out. And the properties of the solid element were updated to reduce the differences of the natural frequencies between the measured and the analysed. In the vibration anlyses, the axial, radial and circumferential properties of the solid element were separately varied to take into account the orthotropic effect of the laminated structure and to match the primary modes of the stator core which were extracted from the modal testing. After several attempts to match the measured natural frequencies and model shapes, the properties of the stator model were determined. Comparison of the vibration analyses results based on the determined properties showed fairly good coincidence with the measured data.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.695-696
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• 2008

This paper deals with the reduction of DC component of cogging toruqe by using the heat treatment of the stator core. The stator core is made of electrical steel sheared by the punching die. From the punching process, large mechanical stress at the edge of stator tooth induces significant plastic and elastic deformation and influences magnetic properties. Then, these phenomenon in the sheared region has influence on the magnetic unbalance in the air-gap of motor. This paper investigated the effect of the punching process on the magnetization process and the mechanical deformation and proposed the stress relief annealing method for the reduction of friction torque among one of motor characteristics.

• Transactions of Materials Processing
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• v.26 no.4
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• pp.240-245
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• 2017

Mixed-model production technology is a method of producing multiple products with one production process and production line in order to reduce wasted manpower and adjust to market trends. In other words, mixed-model production is a flexible production system that changes production volume by model according to market demand. This study has developed a progressive laminated stamping die technology to enable flexible production of a motor core consisting of attaching and detaching the Cam on the back of the punch so that two kinds of stator and two kinds of rotor could be produced in one progressive die.