• Journal of Magnetics
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• v.16 no.1
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• pp.58-63
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• 2011

This paper presents design procedures of a transverse flux linear motor (TFLM). The minimum and maximum flux linkage was determined by the simplified equivalent magnetic circuit and estimated average magnetic flux density at the air gap region by considering the shape of applied magnetomotive force (MMF). With this information, the number of turns of each phase winding was calculated based on the amplitude of applied voltage and speed of a mover. The rated current, coil diameter, and winding area were obtained with the aid of an empirical formula for determining the required MMF. The usefulness of the proposed design method for TFLM is verified by the three-dimensional equivalent magnetic circuit network (EMCN) method and the experimental results of prototyped machine.

• Journal of Advanced Marine Engineering and Technology
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• v.20 no.1
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• pp.49-55
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• 1996

In this paper, the characteristics of a double-sided linear pulse motor (DLPM) with permanent magnet are analysed using the method which combined the coenergy method and the equivalent magnetic circuit method. In the process of computation, the magnetic material nonlinealities of the permanent magnet, the primary and the secondary core are interpolated by the cubic spline method. Then, the equivalent magnetic circuit modelled by the permeance method including airgap reluctance, which is a function of displacement, is obtained. The static thrust which is the derivative of coenergy is computed by Newton Raphson method at each dispacement. And, in order to investigate the characteristics of the DLPM, the thrust shows as a function of displacement, input current and air gap. The simulation resuls are compared with experimental ones obtained from the DLPM with 2 phase and 4 poles.

• Journal of the Korean Society for Railway
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• v.13 no.4
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• pp.404-411
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• 2010

Authors conducted a deduction and characteristic calculation of the some parameters using a magnetic equivalent circuit method to verify a basic design result of a rotary-typed small-scaled linear induction motor for a railway transit. In a LIM, it is possible to express the parameters of the magnetic equivalent circuit into a function of the shape of the secondary aluminium plate and the airgap between the LIM primary core and the secondary aluminium plate. It means that the LIM properties can be changed considerably by the shape of the secondary aluminium plate and the airgap between the LIM primary core and the secondary aluminium plate. So, authors analyzed a tendency of changes of the magnetic equivalent circuit parameters and the LIM characteristics by changing of the airgap, the thickness of the secondary aluminium plate and the overhang length and shape of a rotary-typed small-scaled LIM, and accomplished a basic research to develop a real-scaled LIM for a railway transit.

• Journal of Magnetics
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• v.21 no.3
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• pp.379-386
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• 2016

To satisfy the requirement of magnetically suspended control moment gyroscope (MSCMG) that magnetic bearing can provide torque, a novel 4DOF hybrid magnetic bearing (HMB) with integrated structure was designed. Mathematical models of forces and torques are established by using equivalent magnetic circuit method. The current stiffness, displacement stiffness, tilting current stiffness and angular stiffness of the 4DOF hybrid magnetic bearing are derived by the mathematical models. Equivalent magnetic circuit method and finite element method (FEM) simulation results indicate that the force has a good linear relationship with both displacement and current, and the torque has a good linear relationship with angular displacement and current. The novel 4DOF HMB is capable of achieving control in both two radial translational degrees of freedom (DOF) and also two radial rotational DOFs. The 4DOF HMB is well adapted to MSCMG system, exhibiting advantages in the controllable DOF, light weight and easy to control.

• 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.

• Journal of Magnetics
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• v.16 no.4
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• pp.386-390
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• 2011

This paper deals with the magnetic equivalent circuit modeling and permanent magnet (PM) performance evaluations of a pole changing memory motor (PCMM). We use a coupled transient finite element method (FEM) and Preisach modeling, which is presented to analyze the magnetic characteristics of the permanent magnets. The focus of this paper is on the evaluation of characteristics such as the magnetizing direction and the pole number of the machine under re- and de-magnetization conditions.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.8 s.173
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• pp.42-49
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• 2005

Our purpose is to develop a precision magnetic displacement sensor that has sub-micron resolution and small size probe. To achieve this, we first have tried to establish mathematical models of a magnetic sensor in this paper. The inductance model that presents basic measuring principle of a magnetic sensor is based on equivalent magnetic circuit method. Especially we have concentrated on modeling of magnetic flux leakage and magnetic flux fringing. The induced model is verified by experimental results. The model, including the magnetic flux leakage and flux fringing effects, is in good agreement with the experimental data. Subsequently, based on the augmented model, we will design magnetic sensor probe in order to obtain high performances and to scale down the probe.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.958-964
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• 2015

This paper implements a model of a double excited three-degree-of-freedom motor (3-DOF) coupled with a PI current controller for position control. The rotational trends of the rotor according to the applied steps are identified using a motion equation. The simulation model is a complete electrical and mechanical model of a 3-DOF motor, which mainly consists of mechanical torque equations, a nonlinear equivalent magnetic circuit, and a PI current controller. This machine is tested using the manufactured control board using the same conditions as in the simulation, where the experimental results also verify the accuracy of the simulation results.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.11
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• pp.597-603
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• 1999

Due to its simple construction, operation steadiness and low cost, claw pole step motor is widely used for OA machine and automobile. This paper deals with analysis fo claw pole motor, especially eyeing to dynamic characteristics. To analyze dynamic characteristics of claw pole step motor, torque development in each angular step of rotor are surveyed and torque equation is drived using permeance method. To adopt the airgap MMF, the magnetic equivalent circuit of the motor is introduced. On the base of the magnetic equivalent circuit, the air gap flux equation is derived. To get a optimum design of the motor, the torque characteristic is studied in variation of coil data and remanence value of permanent magnetic material.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.885-887
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• 2000

The paper proposes the characteristic analysis method to consider the saturation of teeth and poles in the hybrid stepping motors. The proposed method is based on the equivalent magnetic circuit coupling with the finite element analysis. The equivalent magnetic circuit is used to analysis the characteristics of the hybrid stepping motors. And the FE analysis is used to compute the non-linear parameters included the equivalent magnetic circuit in the hybrid stepping motors. Simulation and experiment results show that the proposed technique is compared with the classical method.