• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.11
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• pp.1558-1563
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• 2015

In this paper, temperature characteristic analysis was performed by using a thermal equivalent circuit. To suppress the temperature rising, the cooling fan was installed in rotor. The temperature of permanent magnet was reduced from 66[$^{\circ}C$] to 55[$^{\circ}C$] by installing the fan. The temperature of the permanent magnets is difficult to measure. Therefore the temperature of end winding was measured directly by the thermo couple. The validity of this study was demonstrated as compared the calculated results with experimental ones.

• Tribology and Lubricants
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• v.23 no.6
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• pp.283-287
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• 2007

Permanent-magnet (PM) passive bearings use the repulsive forces between the rotor and the stator magnets for the bearing function. It is desirable that the stiffness of the bearing is maximized with the given volume of the magnet. The stiffness is affected by the magnet strength, the number of layers, and the magnetization patterns. Previously, finite-element method (FEM) has been used to maximize the stiffness of the bearing. In this paper, we used the equivalent current sheet method to calculate the stiffness. The validity of this approach is checked against FEM results. The optimized bearing is applied to a micro flywheel energy storage system.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.19-21
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• 2008

The purpose of this paper is the optimal design of a single-phase LSPM(Line-Start Permanent Magnet Motor). A single-phase LSPM has a permanent magnet in the rotor that is same as induction motor. For that reason, magnet is operated by breaking torque in starting region and alignment torque in driving region. Therefore, we need the design process considering the trade-off relationship. In this paper, we propose the design process of a single-phase LSPM for a high starting torque and efficiency with equivalent circuit and FEM. And we use Taguchi Method for considering tolerance in manufacture. Finally, we compared the LSPM that is designed in this paper and conventional induction motor.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.166-168
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• 1996

Since interior permanent magnet synchronous motor(IPMSM) has a structure whose magnet is inserted in the rotor, d, q inductances are differ from each other and the motor produces hybrid torque combined allignment term and reluctance term. But, for their complex magnetic path, it is difficult to analyze this type motors by equivalent magnetic circuit method. So, in this paper, the variation of parameters of IPMSM according to the magnet thickness accuired by using the result from finite element method is presented for the sake of effective design process.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.5
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• pp.652-659
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• 2014

This paper deals with characteristic analysis of double sided permanent magnet linear generator using analytical method. We derived magnetic field solutions produced by permanent magnet and armature reaction based on the 2D polar coordinate and magnetic vector potential. based on the derived magnetic field solutions, Induced voltage is obtained when arbitrary sinusoidal input condition. In addition, electrical parameters such as back-EMF constant, resistance, and inductance are obtained. Finally, generating performance characteristic at the rated load and various load is examined by using equivalent circuit.

• 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 KIEE Conference
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• 2008.07a
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• pp.756-757
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• 2008

Interior permanent magnet synchronous motor (IPMSM) which has high power density is usually applied to traction motor for hybrid electric vehicle. In order to analyze characteristics of IPMSM, d- and q-axis equivalent circuit analysis is generally used. However, the line current of IPMSM calculated by d- and q-axis equivalent circuit analysis differ from measured value. This error is mainly appeared under the flux weakening control. In order to reduce the error between calculated and measured line current, no-load linkage flux which is calculated with considering saturation of magnetic core and armature reaction is applied to characteristic analysis. The result of line current calculated by the method dealt with in this paper is verified by comparison with experimental results.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.5-9
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• 1990

A permanent magnet synchronous motor(PMSM) differs from an ordinary synchronous motor in that the former has no field winding and the field flux can not be controlled by field current. A field-weakening control of PMSM utilizing the demagnetization due to d-axis armature reaction is equivalent to reducing the field current. In this paper, the armature resistance is considered for the optimum field-weakening control.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.331-335
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• 2001

This paper presents the self-commissioning for surface-mounted permanent magnet synchronous motor. The proposed strategy executes three tests with a standard inverter drive system. To do this, synchronous d-q axes currents are appropriately controlled for each test. From the three tests, armature resistance, armature inductance, equivalent iron loss resistance, and emf coefficient are identified automatically. The validity of the proposed strategy is confirmed by experimental results.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.53-57
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• 1989

Until now, method of equivalent circuit is generally used in analyzing the characteristic of the synchronous alternator. But this method can't apply when loads are connected to alternator. In this paper, we analyzed the load characteristic of the synchronous alternator with permanant magnet using 2-dimensional finite element method having voltage source. The loads of a alternator are battary and diodes which are used to rectify. also, we used half periodic boundary condition in the F.E.M calculation