• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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• pp.2179-2189
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• 2010

This paper deals with analytical techniques for performance evaluation of small scaled wind power generator with outer permanent magnet rotor. In part (1), using transfer relations theorem, magnetic field distribution characteristics by PM and armature reaction field are derived. Moreover, electrical parameters such as back-EMF, inductance and resistance are calculated from the obtained field characteristic equations. The proposed analytical techniques are validated by nonlinear finite element method using commercial software 'Maxwell' and performance experiments of the manufactured generator. In part (2), generating characteristics analysis such as constant speed characteristics and constant resistive load characteristics, and performance evaluation according to variation of wind speed will be accomplished using the derived electrical parameters.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.881-882
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• 2008

For the interior permanent magnet synchronous motor(IPMSM) drive to operate above the base speed in the constant horsepower region, the field weakening control is applied. However, the field weakening control was not almost applied to sensorless control of the interior permanent magnet synchronous motor. In this paper, the field weakening control is applied to the sensorless control of IPMSM based on the fuzzy controller. The effectiveness of the proposed system is verified by the experimental results.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.3-6
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• 2002

In this paper, the electrolyte flow treatment is suggested using together with needle and magnet. On account of Lorentz force law, we can not only induce the circulation of body fluids at specific hurt but also apply on the treatment of cell membrane voltage control controlling the electrolyte flow. If electric field is added to human body fluid, electrolyte and then magnetic field is taken by magnet, we can induce local region flow through needle, global region flow with artificial electrical field and magnetic field. Electrolyte flow is excellent treatment in clinical treatment.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.923-924
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• 2006

For the interior permanent magnet synchronous motor(IPMSM) drive to operate above the base speed in the constant horsepower region, field weakening control is applied. However, the field weakening control was not almost applied to sensorless control of the interior permanent magnet synchronous motor. In this parer, field weakening control is applied to the sensorless control of IPMSM based on an instantaneos reactive power. The effectiveness of the Proposed system is verified by the experimental results.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.24-26
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• 1997

A new permanent magnet has been suggested the novel permanent magnet array using advanced analytical approaches in 1979 by Klaus Halbach. In this paper, the Halbach array is utilized to compose the field system. The ferro-magnetic materials of the electric machines cause the fatal energy loses in high frequency. But Halbach any enables to make the various field distribution without ferro-magnetic materials. This paper presents the magnetic characteristics are analyzed by the analytical method and FEM in case that the field system is composed of the Halbach array.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1114-1123
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• 2017

A linear permanent-magnet vernier (LPMV) motor has magnets and windings in the short mover, which is very suitable for long stroke applications. This paper proposed a new field oriented control with space vector pulse width modulation for the LPMV motor, which considers loss minimization. First, the topology of the LPMV motor is briefly presented. Then, the mathematical model is derived, and the mover field oriented control strategy is proposed. Also, the loss analysis is performed. Finally, the simulated and experimental results are given, verifying the feasibility and effectiveness of the proposed control strategy.

• Proceedings of the KIEE Conference
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• summer
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• pp.926-928
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• 2004

For the permanent magnet synchronous motor(PMSM) drive to operate above the base speed in the constant horsepower region, field weakening control is applied. But field weakening control was not almost applied to sensorless control of the permanent magnet synchronous motor. In this paper, field weakening control is applied to the sensorless control of PMSM based on an instantaneos reactive power. And the effectiveness of the proposed system is verified by the experimental results.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.7
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• pp.109-116
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• 2010

The magnet wheel which generates on its interfacing conductive part a repulsive force and a traction torque by rotation of permanent magnets is used to manipulate the conductive plate without mechanical contact. Here, the air-gap magnetic field of the magnet wheel is shielded partially to convert the traction torque into a linear thrust force. Although a magnitude of the thrust force is constant under the fixed open region, we can change the direction of force by varying a position of the shield sheet. So, the spatial position of conductive plate is controlled by not the force magnitude from each magnet wheel but the open position of shield sheet. This paper discusses non-contact conveyance system of the conductive plate using electromagnetic forces from multiple magnet wheels.

• Progress in Superconductivity and Cryogenics
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• v.14 no.3
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• pp.53-59
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• 2012

Adiabatic demagnetization refrigerator (ADR) for hydrogen re-liquefaction operating between 24 K and 20 K has been designed. $Dy_{0.9}Gd_{0.1}Ni_2$, whose Curie temperature is 24 K, is selected as a magnetic refrigerant. The magnetic refrigerant powder is sintered with oxygen-free high purity copper (OFHC) powder to enhance its effective thermal conductivity as well as to achieve relatively high frequency. A perforated plate heat exchanger (PPHE) operated with forced convection is utilized as a heat switch. The forced convection heat switch is expected to have fast response relative to a conventional gas-gap heat switch. A conduction-cooled high Tc superconducting (HTS) magnet is employed to apply external magnetic field variation on a magnetic refrigerant. $2^{nd}$ generation GdBCO coated conductor HTS tape with Kapton$^{(R)}$ insulation (SUNAM Inc.) will be utilized for the HTS magnet. The magnetization and demagnetization processes are to be achieved by the AC operation of the HTS magnet. The designed magnetic field and target ramp rate of the HTS magnet are over 4 T with 180 A and 0.4 T/s, respectively. AC loss distribution on HTS magnet is theoretically estimated.

• Progress in Superconductivity and Cryogenics
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• v.9 no.1
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• pp.76-81
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• 2007

This paper deals with the characteristics of a small scale $high-T_c$ superconducting(HTSC) levitation system. The levitation tester. which models after electrodynamic suspension(EDS) maglev, consists of one HTSC magnet, a reaction plate, and force measuring components. Instead of moving magnet, AC current was applied to the fixed HTSC magnet. The magnet also has persistent current switch(PCS). The inductance of the magnet was 18.5 mH and total joint resistance of the magnet was $5.74{\times}10^{-7}\Omega$. AC current was applied into the HTSC magnet with various frequencies and the levitation force was calculated and measured. According to the increase of the vehicle speed, the levitation force was saturated.