• Journal of Ocean Engineering and Technology
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• v.11 no.4
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• pp.197-204
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• 1997

최근 유도전동기를 이용한 가변속 구동시스템의 수요가 자동화 및 에너지의 효율적 이용 측면에서 육상 산업체는 물론, 선박 및 해양플랜트에도 확산되고 있다. 유도전동기의 토크 고속제어법은 가변속 구동시스템의 고성능화를 위한 필수과제로서, 제어법 적용시 2차저항의 동정문제가 대단히 중요하다. 본 논문에서는 유도전동기의 토크 고속 응답제어계에 있어서 고정도의 토크응답을 실현하기 위한 2차저항 동정법을 제안한다. 제안된 방법은 모터의 회로방정식으로부터 유도되며, 모터의 인가전압과 1차전류 정보로부터 간단히 구현된다. 제안된 방안의 타당성을 검증하기 위하여 펄스폭변조방식의 전압형 인버터를 상정한 수치 시뮬레이션을 수행하며 그 결과를 통하여 제안방식의 유용성을 입증한다.

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.2
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• pp.158-163
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• 2001

Current Source Inverter(CSI), operated in square wave mode, is more efficient thant the PWM CSI because of increased cost, greater complexity of control algorithm and substantial switching losses, EMI. But, the square wave output current of CSI, rich in low order harmonics produce motor torque ripples. Therefore, in this paper, describes active power filters for compensating square wave input current of current source induction motor. Also, notch filtering as compensation algorithm is employed. To confirm the validity of proposed system, PSIM simulation results are presented and discussed.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.163-166
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• 1999

본 연구에서는 SRM의 토크 리플을 줄이기 위한 설계 방법을 제시한다. SRM의 형상을 최적화하기 위해 유한요소법과 최적화 알고리즘을 적용하였다. 기존의 토크 평균값을 이용한 설계법의 문제점을 제시하고 토크 형태를 구간 별로 목적 함수로 정의하여 토크 형태를 최적화하는 새로운 최적화 문제 정의 방법을 제안한다. 이러한 방법으로 최적화할 경우 SRM의 정적 토크 특성만을 고려한 기존 방법에 비해 고속으로 회전하는 SRM의 토크 성능을 보장할 수 있다는 장점이 있다.

• Journal of Aerospace System Engineering
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• v.13 no.3
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• pp.1-8
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• 2019

The electromagnetic forces generate a torque on the gimbal motor, and changes in the coil current causes torque ripple. This affects the gimbals' speed and results to unstable satellite attitude. It is therefore essential to reduce the torque ripple of the gimble motor with the aim of improving the attitude control accuracy of the satellite. This paper theoretically analyzes the torque generated from the modeling of a motor for general concentrated winding and distributed winding. The prototype was designed and fabricated through selection of the winding that reduces the torque ripple through simulation results. The results of the magnetic fields' theoretical analysis and the back electromotive force of the prototype were compared with the calibrated results for verification of conformity and manufacture of the design. The low-speed test proved that the torque ripple is reduced by improving the speed stability.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1654_1655
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• 2009

영구자석형 스테핑 모터 (Permanent Magnet Stepping Motor, PMSM)에서는 그 구조적 특징으로 인하여 필연적으로 코깅 토크 (cogging torque)가 발생한다. PMSM의 성능을 저하시키는 코깅 토크를 제거하기 위하여 Internal Model Principle (IMP)을 제안하였다. IMP를 사용하기 위해 Field-Oriented Control (FOC) 기반의 SISO 시스템을 구성하고 IMP를 PI 제어기에 병렬로 추가하였다. 모의 실험 결과로 코깅 토크로 인한 속도 리플이 효과적으로 제거됨을 보였다.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.2
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• pp.29-35
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• 2011

The behaviors of combustion-induced internal flows of SRM equipped with fin-slot grain and submerged nozzle are very complex and diverse. Cold air-flow tests for 2D and 3D scale models of SRM have been done in order to specify the visualization method to analyze particular internal flow patterns such as roll-torque inducing flow. Swirl flow induced by asymmetric vortical tubes also has been visualized through employing various light source and recording directions.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.7
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• pp.914-919
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• 2004

When the motor is rotating, the torque and rpm are varying as the loads or the driving status connecting through reduction units are changing. On the contrary, one can monitor the changes of the loads or the driving status in the manner of measuring motor torque and rpm. There is a torque measuring method using the strain gauge and bridge circuit. But, because this is the contact method, it has the life time which is dependent on rotating velocity and used time. So this system demands on replacement of some Parts or whole system itself for maintenance. And this system is also relatively big and expensive, requiring preceding annoying process. In this paper, we are going to suppose non-contact method to measure torque and rpm using the Hall effects sensor For this we have made the planetary geared reduction motor with Hall sensors and with the monitoring system. The monitoring system displays the sensing data(torque, rpm) and calculated data( power) and also has the network capability with Bluetooth protocol. Our solution is much more inexpensive ;md simple method to measure torque and rpm than before.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.465-469
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• 2019

In this paper, the design of BLDC (brushless direct current) motors based on torque and back-EMF equations was carried out to assess the application of the motor in concrete vibrators. The air gap flux density of the motor is an important parameter because the length of the motor and the size of the diameter are given. The air gap magnetic flux density was calculated through a simplified magnetic circuit, and basic design of the shape and dimensions of the motor were then determined by carrying out experiments based on torque, back-EMF, and air magnetic flux density equations. After setting the outer and inner diameters, stack lengths, and rated speed of the motor, a detailed design was performed by simulations using the finite element method by designating the diameter and thickness of the motor as the key parameters. The final design to satisfy the target torque and the lowest THD (Total Harmonic Distortion) was carried out along with a simulation.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.5
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• pp.827-834
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• 2023

In this paper, a slotless outer rotor BLDC motor for a vehicle blower was designed and manufactured to improve the disadvantages of general motors. The proposed motor solves the noise caused by mechanical friction of DC motor during rotation by removing the brush, Also, slotless air-gap windings are used to improve cogging torque by BLDC motor slots. Then, the motor has a structure in which a magnet is attached to the external rotor and rotates simultaneously with the internal rotor, there is no change in magnetic flux. Therefore, it has high efficiency by fundamentally reducing iron loss.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.291-294
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• 2004

Many researches have been focused on optimal designs of a pole shape in order to reduce cogging torques, which are generated between permanent magnets and slots. In this paper, an adaptive controller is proposed for reducing the effect of cogging torques in servo motors. The controller stabilizes the control system and shows an excellent trajectory tracking performance compared to the conventional PD controller.