• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.181-182
• /
• 2007

This paper presents the system design of high speed linear synchronous machine in the required speed and thrust considering power of inverter. in this paper, the design of manufacturing motor is optimized by characteristics of motor parameters with the variation of coil turns of rotor and stator. And, the dynamic simulation are performed from the (d-q) transformation of the current and voltage and the mechanical dynamic equation composed of the mover mass and damping ratio. Finally, the results of design and analysis are verificated by finite element analysis.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.52 no.4
• /
• pp.154-154
• /
• 2003

The switched reluctance motor(SRM) has a considerable potential for industrial applications because of its high reliability as a result of the absence of rotor windings. In some applications with SRM, a parallel switching strategy is often used for cost saving, increasing of current capacity and system reliability. This paper proposes a new parallel switching strategy of SRM using parallel winding. While conventional parallel switching devices are connected in a phase winding, power devices are connected in the parallel windings wound in each pole of stator in the proposed method. Paralleling strategy for current sharing in the proposed method can be easily determined without considerations of any nonlinear characteristics of power devices such as conduction resistance, threshold voltage and gain factor. The proposed paralleling strategy is verified by the mathematical analysis and experimental results.

• Proceedings of the KIEE Conference
• /
• 2001.10a
• /
• pp.104-106
• /
• 2001

In this paper, it is object of design of high efficiency slotless BLDC motor using film coil. Slotless BLDC motor is able to have high efficiency property and low cogging torque, due to magnetization of stator core have constant contribution by slotless core. But it is difficult to make coil winding of slotless BLDC motor. So we make amateur of slotless BLDC motor using film coil. Film coil is fabricated by drilling, electro-plating and etching of copper/insulator/copper plate. In this paper, after design of slotless BLDC motor for moving axial blower, it is fabricated by NdFeB permanent magnet type rotor and film coil.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1180-1182
• /
• 2005

In this paper, the design and field analysis of the novel axial flux type permanent magnet(AFPM) motor with double stator and single rotor are investigated. The various design schemes of AFPM based on 3D finite element method are proposed. The effects of slot shapes, various magnetization of PM, and skewing on the cogging torque and average torque have been investigated in detail. From the results, we can improve the cogging torque and average torque characteristics.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1183-1185
• /
• 2005

This paper describes the optimal design and performance characteristics of the BLDC Motor for Electrical Power Steering System. To develope the optimal dimension within a given volume, BLDC Motor with the low cogging torque is designed and analyzed by FEM analysis. The prototype BLDC Motor has 4 poles rotor and 24 slots stator. To estimate the prototype machine, this paper gives the comparison between the FEM results and the experiment ones.

• Proceedings of the KIEE Conference
• /
• 2005.07b
• /
• pp.1204-1206
• /
• 2005

This paper deals with magnetic field analysis and computation of cogging torque in IPM motor with an analytical method, which is based on the Conformal Mapping technique. The magnetic field is analyzed by solving space harmonic field analysis due to inserted PM magnetizing distribution. Conformal Mapping method is then used for considering the slot opening effect and rotor saliency effect on the air-gap field magnetic distribution. Then, by integrating the field over the stator surface, cogging torque is calculated. The validity of the proposed analytical method is confirmed by comparing the results with 2-D FEA results.

• Proceedings of the KIEE Conference
• /
• 1998.11a
• /
• pp.171-175
• /
• 1998

This paper proposes a speed sensorless vector control of induction motor using a minimum-order EKF(extended kalman filter). Minimum-order EKF has the advantage of reducing the computational estimation cost because the stator current is not estimated. EKF does not deteriorate the performance of the overall speed control system, even though the measurements are relatively noisy. The estimated rotor speed is used for vector control and overall speed control. Computer simulations of the speed sensorless vector control are carried out to test the usefulness of the minimum-order EKF algorithm.

• Proceedings of the KIEE Conference
• /
• 1995.07a
• /
• pp.42-45
• /
• 1995

This paper describes the flux density in air gap, harmonic torques occurring by inadequate slot combination of induction motor using the fourier series. The analysis uses DFT(Discrete Fourier transform) to analyze harmonic orders of flux density. It is certified that the harmonic flux density has the same result using Fourier series and FEM.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.26 no.2
• /
• pp.219-226
• /
• 2002

This paper is concerned with the effects of periodically approaching upstream wakes on cascade-flow and loss. The reduced frequency of the periodic wakes was varied in the narrow range from 0.5 to 0.7 Corresponding to a wake-passing through the cascade, two velocity deficits appeared near the boundary layer contour in the downstream from about 60% chord-length. The first velocity deficit was caused by a periodic wake and the second one appeared after some delayed time. The second velocity deficit was interpreted as the results of reattachment of flow-separation. The higher reduced frequency decreased the duration time of separation appearance and the lesser losses of blade were resulted.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.08a
• /
• pp.22-22
• /
• 2010

배기속도 2500 L/s, 최고진공도 $10^{-10}$ mbar를 구현할 대용량 복합 분자펌프 설계를 위한 3차원 유동해석을 실시하였다. 진공도가 $10^{-5}$ mbar 이상이 되는 고진공도에서는 Knudsen 수가 $10^2{\sim}10^7$에 이르러 분자간 충돌을 거의 무시할 수 있게 되며, 이때의 유체해석 방법으로서는 통상 희박기체 해석법으로 많이 쓰이는 Direct simulation Monte Carlo 방법보다, 충돌이 없는 분자의 자유운동을 모사하는 Monte Carlo 방법이 더 적합하게 된다. 본 연구에서는 다단계 rotor와 stator로 구성되는 복합분자 내 유동장에 Monte Carlo 해석법을 적용하여 유동해석을 실시하였다. 먼저 2차원 해석을 실시하여 분자펌프의 성능에 중요한 영향을 미치는 설계변수들을 도출하고, 이 설계변수들의 최적값을 다양한 3차원 유동해석을 통해 도출하였다. 해석결과는 펌프설계에 적용되어 펌프 성능시험결과를 통해 확증된다.