• Journal of Power Electronics
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• v.19 no.1
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• pp.158-167
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• 2019

This research comparatively studies three kinds of flux regulation methods, namely, stored capacitor discharge pulse (SCDP), constant current source pulse (CCSP), and quantitative flux regulation pulse (QFRP), which are used for hybrid permanent magnet (PM) axial field flux-switching memory machines (HPM-AFFSMMs). Through an analysis of the operation principle and the series hybrid PM flux regulation mechanism of the objective machine, the circuit topologies and flux regulation process of these flux regulation methods are addressed in detail. On the basis of a simulation, the flux regulation characteristics of the researched machine during the magnetization and demagnetization processes are comparatively evaluated. Then, machine performance, including back EMF, direct and quadrature axis inductances, and magnetization and demagnetization characteristics, is quantitatively investigated. Results show that the QFRP enables the HPM-AFFSMM to achieve a less harmonic component of back EMF by approximately 7.28% and 7.97% at the magnetization and demagnetization states, respectively, and a more complete magnetization process than the SCDP and CCSP.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.1954-1959
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• 2014

This paper attempts to design and present a comparison of classical Direct Torque Flux Control (DTFC) for Line-Start Permanent Magnet Synchronous Motor (LSPMSM) and its equal Permanent Magnet Synchronous Motor (PMSM). In order to present an in-depth analysis, both motors for DTFC Voltage Source Inverter (VSI)-fed in the same situations of different conditions are simulated and tested. The advantages of the proposed method for LSPMSM over the PMSM are discussed and analyzed.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.10
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• pp.507-513
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• 2003

Nowadays, the necessity of linear position control motors have been increased in the various fields of the automatic control system. In the recently, the position control motor have disadvantaged in the efficiency and economical view since it require a conversion equipments such as belt and gear in order to convert rotary to linear motion. On the contrary, the hybrid linear stepping motor(HLSM) of linear motion digital actuator has a direct drive method that do not need mechanical conversion equipments. Therefore, the HLSM is better advantaged in the efficiency and economical view than a rotary stepping motor. In this paper, we have designed an optimum tooth shape and a permanent magnet value between the mover teeth by the 2D finite element method(FEM) to develop the HLSM with longitudinal flux machine(LFM) type, and calculated the thrust force and normal force. And we have manufactured the prototype of it. and have experimented the thrust force and the dynamic thrust characteristics of it.

• International Journal of Aeronautical and Space Sciences
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• v.1 no.2
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• pp.30-42
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• 2000

On-orbit thermal environment test of KOMPSAT was performed in early 1999. An analysis of the test data are addressed in this paper. For the thermal-environmental simulation of spacecraft bus, an artificial heating through the radiator zones and onto some critical heat-dissipating electronic boxes was made by Absorbed-heat Flux Method. Test data obtained in terms of temperature history were reduced into flight heater duty cycles and converted into the total electrical power required for spacecraft thermal control. Verification result of flight heaters dedicated to the bus thermal control is presented. Additionally, an exhaustive heating-control process for maintaining the spacecraft thermally safe and for realistic simulation of the orbital-thermal environment during the test are graphically shown. Qualitative suggestions to post-test model correlation are given in consequency of the analysis.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.724_725
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• 2009

This paper deals with control parameters deduction and dynamic analysis of hybrid thrust magnetic bearing(HTMB). The flux density at air-gap is obtained from system modeling which considers permanent magnet and electro magnet. The vertical force is derived from flux density using maxwell's stress tensor. An accurate linear model is obtained by using linear approximations of the attraction force around the nominal equilibrium point. The dynamic simulation of the HTMB using the PD controller is conducted and control parameters are deducted.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.165-170
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• 2015

In this paper, The strength and driving characteristics of it were investigated according to developing the traction motor for 8200 electric locomotive series. For this purpose, Flux density strength was analyzed and then structural strength was investigated such as a stator frame, design of the rotor shaft bearing according to the design process. In addition, the traction motor operating point was analyzed according to slip frequency variation at a power source frequency. As the results of analysis on torque-speed characteristic curve, we was confirmed that traction motor was controlled as torque control prior to motor speed 1610[rpm], power control between 1610[rpm] and 2500[rpm] and breakdown torque control more than motor speed 2500[rpm].

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.942-948
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• 2011

This paper deals with characteristic analysis of axial flux permanent magnet (AFPM) machines with axially magnetized PM rotor using quasi-3-D analysis modeling. On the basis of magnetic vector potential and a two-dimensional (2-D) polar-coordinate system, the magnetic field solutions due to various PM rotors are obtained. In particular, 3-D problem, that is, the reduction of magnetic fields near outer and inner radius of the PM is solved by introducing a special function for radial position. And then, the analytical solutions for back-emf and torque are also derived from magnetic field solutions. The predictions are shown in good agreement with those obtained from 3-D finite element analyses (FEA). Finally, it can be judged that analytical solutions for electromagnetic quantities presented in this paper are very useful for the AFPM machines in terms of following items : initial design, sensitivity analysis with design parameters, and estimation of control parameters.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.852-857
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• 1988

In induction motor control, power efficiency as well as high dynamic performance is important. We attempt to achieve both of them by decoupled control of rotor speed and flux. A nonlinear feedback controller with a well-known rotor flux observer is proposed with its stability analysis. Experimental results demonstrate that the proposed control method based on recently developed nonlinear feedback control theory is of practical use.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.5
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• pp.247-253
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• 2015

The presented work demonstrates the effects of flow rate on the secondary side of DHS (District Heating System). Increasing flow rate at the secondary side of DHS decreases energy consumption and time to reach the set-point of the heated room while increasing heat flux on the floor in the heating space. When flow rate increases, the overall heat transfer rate of radiant floor also increases. However, the results also show overall heat transfer rateto not increased linearly and thus the existence of an optimal flow rate for the secondary side of DHS. Control of the radiant floor with hot water may be more effectively accomplished with a combined control strategy that includes heat flux and a temperature set-point. This experimental analysis has been performed using a lab-scaled DHS pilot plant located at Jeonju University in Korea.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.325-327
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• 1998

Disk type single-phase switched reluctance motor which has an advantage of simple robust construction, simple control circuity, and low manufacturing cost has a specific property of axial flux machine and radial flux machine simultaneously. So, this DSPSRM has a complicated magnetic circuit and it is difficult to analyze characteristics of DSPSRM for design. In this paper, we used to analyze the effects of radial flux and axial flux simultaneously by 3D-finite element method. From the results of 3-D FEM, we obtained the approximated torque characteristics of DSPSRM. It's analysis results can be used in optimal design of DSPSRM considering the saturation.