• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.548-551
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• 2004

Magnetostrictive actuators have seen increasing use in fine positioning system because it has many advantages such as friction free, resolution of ${\mu}{\textrm}{m}$ or nm scale, and powerful output force. Usually, the magnetic circuit of magnetostrictive actuator has components which are flux return path, coil, and magnetostrictive material. It is classified in two types according to existence of the permanent magnet. The magnetic circuit having optimal performances transfer magnetic field which is obtained by providing input current at coil without energy loss. This paper described mathematical model of magnetic circuit for getting design variables. The modeling equation is obtained from the relations between flux and reluctance of the magnetic equivalent circuit. Also, finite element analysis has been used to study the performance of magnetic circuit according to change of design variables such as existence and shape of the permanent magnet, flux return path etc. The modification of dimensions enables us to optimize magnetic circuit.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.751-753
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• 2001

The characteristic of magnetostrictive is to change shape in a magnetic field, TERFENOL-D is said to produce magnetostriction. A magneto strictive actuator need to the magnetic circuit. The most important design consideration is the magnetic circuit. The magnetic circuit consists of the solenoid coil, permanets for bias and shaping of the other parts through which the magnetic field passes. A good magnetic circuit ensures the proper magnetic field in th TERFENOL-D and very uniform magnetic field in all phases of the actuator operating cycle. This paper presents magnetic circuit design and analysis uesing FEM.

• Journal of Power System Engineering
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• v.1 no.1
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• pp.144-153
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• 1997

The magnetic levitation system is utilized in the magnetic bearing of high-speed rotor because of little friction, no lubrication, no noise and so on. The magnetic levitation system need the feedback controller for the stabilization of system, and gap sensors are generally used to measure the gap. The use of gap sensors brings out the increase of the number of troublesome, and the decrease of the control performance because of the dislocation between the measurement point and the control point. This paper presents the design of the gap estimation circuit for the sensorless method proposed by authors in the magnetic levitation system. We made the gap estimation circuit which was composed of both the superposition circuit and the measuring circuit. And we investigated the validity of the usefulness of the proposed sensorless method in the magnetic levitation system through results of actual experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.652-655
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• 2003

This paper is about the recent development of the magnetic impact actuator for endoscope. The developed magnetic impact actuator has many problems to arrange in the system body. Because the magnetic impact actuator need a permanent magnet as an impacter, so the magnetic interference among magnets can not be eliminated. This interference causes the system size bigger. We need a new actuator design to solve these problems. One of the good solutions is to use the closed electro-magnetic circuit. This kind of circuit enhances the actuators to be independent. It is written about the design of the electro-magnetic circuit and simulation using Maxwell(version 9.0)

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.406-409
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• 2008

This paper presents the integrated magnetic circuit designing method for phase shift full bridge(PSFB) converter. The integrated magnetic circuit is implemented on redesigned of EI core. The transformer windings are located on center leg and the two inductors are located on the outer legs with air gap. Based on the equivalent circuit model, the principle of operation of the PSFB converter is explained. The operation and performance of the proposed circuit are verified on a 1.2 kW prototype converter. The analysis and design of the integrated magnetic circuit is verified through the experimental and simulation results.

• Journal of Magnetics
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• v.19 no.4
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• pp.404-410
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• 2014

This paper considers the design and performance evaluation of interior permanent magnet synchronous motors (IPMSMs). The initial design such as the sizing and shape design of the stator and rotor is performed for a given load condition. In particular, the equivalent magnetic circuit (EMC) is employed both to design the mechanical parameters of the rotor while considering nonlinear magnetic saturation effect and to analyze the magnetic characteristics of the air-gap of the motor. The designed motor is manufactured and tested to confirm the validity of the design processes and simulated results.

• International Journal of Railway
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• v.3 no.1
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• pp.14-18
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• 2010

This paper describes design and characteristic analysis of long primary type linear synchronous motor (LSM) for high speed train system. LSM is designed using loading distribution method and magnetic equivalent circuit. For characteristic analysis of LSM, analytical and numerical methods are applied. Analytical method for solving the magnetic field distribution of the analytic model is based on the Maxwell’s equations. Using the characteristic equation and magnetic equivalent circuit, we analyze the effect of variation of parameters, and then we validate the result by comparing with numerical method by finite element method (FEM). We compare the analytical method with numerical method for analyzing the effect by variable parameters. This result will be useful of design and forecast of performance without FEM.

• Journal of Mechanical Science and Technology
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• v.17 no.11
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• pp.1616-1627
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• 2003

This paper describes a mini linear optical pickup actuator. To reduce the size, inner yokes are designed to guide the mover and outer yokes of permanent magnets are removed. Magnetic circuit method is used to determine the thrust force. Virtual path method is proposed to analyze the open magnetic circuit analysis. The magnetic circuit of the proposed actuator can be a closed circuit due to the virtual path model of the outer magnetic flux. The validity of virtual path method is evaluated by comparing to the FEM analysis. Structural vibration is investigated using FEM and the design of the mover is modified to improve the vibration characteristic. Dynamic characteristic experiments shows that the performance of the proposed actuator is enough to be used as a coarse and fine seeking actuator simultaneously and the thrust force margin for loading a focusing actuator is guaranteed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.207-211
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• 2004

The performance of an inductive position sensor has approved by previous research papers. In this paper, magnetic circuit model of a ring-type multi-pole insuctive position sensor is described. The magnetic circuit model is required to design in ductive position sensor as well as draw a fault tolerance algorithm. Using the magnetic circuit theory, we derived the relationship between voltage applied and flux density in the normal air-gap. By idealizing the modulation/demodulation processes of signal processing circuit, sensor gain with respect to change of displacement is theoretically calculation using the magnetic circuit model, which validate the theoretical derivation.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.573-578
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• 1988

The objectives of this paper are to establish an equivalent magnetic circuit of the hybrid PM step motor and to apply the canonical piecewise linear eqation and the Kazenelson algorithm of solving the nonlinear magnetic circuit, so that the static holding torque and the magnetic properties of the motor are determined. The results of that are applied to the design of the hybrid step motor.