• Proceedings of the KSME Conference
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• 2004.11a
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• pp.690-695
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• 2004

The present study is an investigation on the characteristics of heavy load toque converter by experimental process. To get the dynamic performance, the dynamometer was used with a parameters of speed, torque, oil pressure and oil flux, etc. The torque converter was tested for various input speed, output oil pressure and input oil flow rate. All experiments were investigated in case that the speed ratio is increased. The torque ratio and capacity factor was in inverse proportion to speed. Engine revolution had a more effects at region of low speed ratio. But, the opposite phenomena were represented increase of efficiency. In result of this experiments, the characteristics of torque converter were not influenced by oil pressure and oil flux.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.67-69
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• 2004

This paper describes an approach to design a interior permanent magnet motor(IPM motor) for the reduction of cogging torque. The magnitude of the torque ripple and cogging torque in a interior permanent magnet motor(IPM motor) are generally dependent on several major factors: the shape of stator tooth tip, slot opening width, air gap length, the shape of barrier preventing flux leakage of magnets, magnet configuration and magnetization distribution or magnet poles. In this paper, the IPM BLDC motor is designed considering a saturated leakag flux between the barriers on the rotor for increasing the efficiency and decreasing the magnitude of the cogging torque. Analytical model is developed for the IPM BLDC motor with a concentrated winding stator. The results verifies that the proposed design approach is very efficient and effective in reducing the cogging torque and the torque ripple of the IPM BLDC motor to be used in an electric vehicle.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.277-282
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• 2010

Imported vane type air motor and-piece is used widely in the domestic dental services. The imported hand-pieces are more than 90 percent in the domestic market. The air-motor unit of the hand-piece had not been developed inside of the country yet. Therefore it needs some research works. Purpose of this study is to design the air motor of the hand-piece for better performance. The geometry of the air-motor is based on product of NSK Company. The airflow of the air motor unit is simulated by Computational Fluid Dynamics. The performance analysis of the air motor units is investigated. ANSYS 12.0 CFX is used to analysis of the flowfield. Torque changes depends on spin calculated by the immersed solid method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.682-688
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• 2008

Transverse flux machine (TFM) has been considered as a promising driving machine especially at the low-speed applications because it has higher power density, torque and efficiency than the conventional electrical motors. However, it has complicated structure, large torque ripple and sometimes unbalanced magnetic force due to its inherent structure. This paper investigates the characteristics of torque ripple and unbalanced magnetic force of a rotatory two-phase TFM due to the teeth geometry by using the 3-dimensional finite element method, and it develops a rotatory two-phase TFM with herringbone teeth to reduce the torque ripple as well as to eliminate the unbalanced magnetic force.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.924-929
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• 1994

In using a performance model of a torque converter determined by its gemetric condition, it is possible that the analysis of two arbitrary converters produces the the same results because of the same value of equivalent parameters despite their different shapes. Therefore, it is necessary to understand the effect of shape factor on dynamic perfomance, and equivalent parameters reoresenting a performace model of a converter should into its defined by the behavior of flow field. In this study, torus flow of a torque converter is changed into its equivalent system defined by the behavior of flow, and govering equations for the system are presented and used for analysis. Equivalent parameters are obtained from the results of flow analysis and are compared with parameters of one dimensional performance model. The influence that shape change of a converter has on the behavior of flow and the equivalent parameters is studied qualitatively.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1007-1009
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• 2010

실험을 통하여 엔진의 성능을 파악하고자 한다면 적지 않은 시간동안 많은 비용과 노력이 필요하다. 최근 연구에서는 이러한 단점을 해결하기 위해 CFD를 이용 선행해석을 통해 미리 그 엔진의 성능을 예측하여 실험에 들이는 시간과 비용을 줄여가고 있다. 본 연구는 실험을 통하여 소형엔진의 성능을 알아보기 이전에 선행해석을 통해 소형엔진의 성능을 예측하고자 한다. 소형엔진의 선행 해석을 위해 전자제어 연료분사 방식의 400cc급 소형엔진을 모델링하고 1D 해석프로그램인 GT-Power를 통하여 엔진의 Toque, Power 및 배기가스를 예측하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.6
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• pp.42-48
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• 2011

Generally, the structure without the stator core Axial Field Permanent Magnet (AFPM) generator was simple and there was nearly no cogging toque. And because it had the wide driving rate area, it had been being mainly used in the small wind power generation system. However, AFPM generator with non-slotted stator can't generate high voltage at low wind speed due to long air-gap. It is the reason of output efficiency drop. Therefore, in this paper, the AFPM synchronous generator with internal rotor and dual slotted stators for the small wind turbine is studied, and deal with a cogging torque minimization through the determination of optimum pole-arc ratio.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.4
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• pp.307-310
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• 2011

In this paper we use general centrifugal pump instead of screw pump in alternative Energy system. This alternative Energy system with screw pump compared the volume flour of water pumping and efficiency. Screw pump is designed that it rotated without a toque in another Shaft. Futhermore it have noise and abrasion, The pump used in high pressure with fast rotate.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.7
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• pp.48-54
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• 2014

This paper discusses study of torque ripple minimization employing an improved TDF(torque distribution function)-based instantaneous torque control to reduce acoustic noise and vibration problem of the SRM. As the flux linkage of the SRM is a nonlinear function of phase current and rotor position, design of optimal controller for the SRM is quite complicated. Hence, an accurate mathematical model considering the nonlinearity of the SRM is required. An improved TDF based torque control has been proposed in order to reduce the toque ripple at high speed operation. Dynamic simulation using Matlab/Simulink as well as Finite Element Analysis is presented. A prototype SRM for electric vehicle traction has been manufactured to validate the experimental results comparing the dynamic simulation results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.7
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• pp.1204-1210
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• 2016

The phase currents must be accurately measured to achieve the instantaneous torque control of AC motors. In general, those are measured using the current sensors. However, the measured current signals can include the offset errors and scaling errors by several components such as current sensors, analog amplifiers, noise filter circuits, and analog-to-digital converters. Therefore, the torque-controlled performance can be deteriorated by the current measurement errors. In this paper we have analyzed the influence caused by vector control of 2-phase induction motor when two errors are included in measured phase currents. Based on analyzed results, the compensation method is proposed without additional hardware. The proposed compensation method was applied vector-controlled inverter for 2-phase induction motor of 360[W] class and verified through computer simulations and experiments.