• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.3
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• pp.365-373
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• 1996

This paper presents the effects of rotor time constant variation and the on-line tuning algorithm of the rotor time constant. If the value of the rotor time constant is set incorrectly, the IFOC (Indirect Field Oriented Control)scheme exhibits deteriorated performance according to the wrong slip command. These variation effects of the rotor time constant are caused by the slip calculator where it is known that the rotor time constant play an important role in the aligned rotor flux. Using the two torque angles (stationary torque angle, rotating torque angle), the variation of the rotor time constant is identified, and the rotor time constant of the controller is tuned to the proper value of the machine. As the result, with the proposed algorithm, the dynamics of the deteriorated IFOC system, where the rotor time constant is varied, is improved. For the purpose of the validity of this proposed algorithm, the computer simulations and the experiments have been performed and the explanation of the results is presented. (author). refs., figs., tab.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.258-262
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• 2008

Micro forming is a suited technology to manufacture very small metallic parts(several $mm{\sim}{\mu}m$). In this study, the micro forming property was studied, using Al5083 superplastic alloy with micro grain, suitable for the micro forming process and Zr-BMG amorphous with pseudo-superplastic phenomena in the supercooled liquid state. Micro forming experiments under stastic load status showed that distortion by slip and spin of the grain system and slip inside the grain was observed in the Al5083 superplastic alloy. In case of Zr-BMG, because there is no grain, the distribution of the forming property was similar to the load distribution between punch and metal.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.6 s.123
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• pp.524-530
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• 2007

This paper presents a friction model to realize self-excited vibration of multi-body systems. The friction coefficient is modeled with a spline function in most commercial codes. Even if such a function resolves the problem of discontinuity in friction force, it cannot realize self-excited vibration phenomena. Furthermore, as the relative velocity approaches zero, the friction coefficient approaches zero with the conventional model. So, slip occurs when small force is applied to the system. To avoid these problems a new friction model is proposed in this study. With the new friction model, the self-excited vibration can be realized since the friction coefficient changes with the relative velocity. Furthermore, the slip phenomena could be reduced significantly with the proposed model.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.19-23
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• 2009

This paper focuses on vehicle fuel economy improvement using D-Range neutral control of automatic transmission. The system objected to reducing of fuel consumption during idle. Usually, turbine of conventional auto transmission is mechanically linked to wheel during idling condition. Therefore speed ratio of torque converter is zero for that period. This causes needless power loss by the torque converter slip. To improve this inefficiency automobile makers develops electronically-controlled D-range neutral control system. The D-range neutral control system minimizes slip on the torque converter by shifting gear to a neutral position during vehicle stoped with D-range gear position. However there's insufficient study about the effect of D-range neutral control system on vehicle fuel economy. In this paper, researches are performed on effect of D-range neutral control system on vehicle fuel economy by experiment with two different vehicle. And it is also estimated the effect on vehicle fuel economy using computer simulation. As a result, 1.8% of LA-4 mode fuel economy improvement can be achieved in a vehicle by D-range neutral control system.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1845-1850
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• 2011

Permanent Magnet Synchronous Motor(PM motor) of Advanced EMU is the direct drive morot(DDM) without using reduction gear and Interior buried Permanent Magnet Synchronous Motor(IPMSM). Propulsion system for IPMSM control is composed 1C1M. 1C1M is good for each motor control and anti slip/slide. Propulsion control system have completed running test on field and reliability test is in progress.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.4 no.2
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• pp.12-17
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• 1995

The operation of heavy tracked vehicle has the problems in the steering that made by misoperations. The protection device is applied to the vehicles. But that device is applied to the vehicles. But that device has the engine stop and over load condition problems. the steering safety system is developed on the basis of clutch slip that proved the durability in the dynamo test and field test. The steering safety system caused the performance improvement of vehicles when steering.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.801-809
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• 1993

This paper presents the design of an automatic propellant system model in order to improving tractive performance of tractor. The theoretical basis of automatic control , the characteristics and function of the system, and the kinematic analysis are also discussed.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.98-101
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• 1988

The purpose of the paper is to operate a high-dynamic-performance for ac servo system. It is describes a characteristics and stability regions by linearized control system of squarriel-cage induction motor. Designed control system are compose to slip-frequency vector control for controlled a scandary interlinked flux by PWM inverter.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.9
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• pp.1051-1059
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• 1988

In this study, we developed a proto-type RTP equipment by using tungsten halogen lamps. The system has been designed utilizing the result of the numerical analysis of the reactor. In order to analyze the system performance, experiments for activation of implanted atoms and oxidation process were performed. As a result, we obtained 2-3% uniformity in sheet resistance and 2-4% uniformity in oxide thickness, although after a long time process at high temperatures slip lines and warpage of the wafer have been observed.

• Magazine of the Korea Concrete Institute
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• v.16 no.2 s.79
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• pp.52-56
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• 2004