• 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].

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.7
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• pp.930-936
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• 2003

A new method of direct current motor drive, which requires neither shaft encoder nor speed estimator, is presented. The proposed scheme is based on decreasing current gap between a numerical model and an actual motor. By supplying the identical instantaneous voltage to both model and motor in the direction of reducing the current difference, the rotor approaches to the model speed, that is, reference value. The performance of direct current motor drives without speed sensor is generally poor at very low speed. However, in this system, it is possible to obtain good speed performance in the low speed range.

• Journal of KSNVE
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• v.8 no.4
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• pp.670-682
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• 1998

Ball type automatic balancer is used to reduce the vibration caused by unbalance of rotor. In this study, A analytic modeling of a front loaded washing machine with ball type automatic balancer has been suggested theoretically and ADAMS has been used to analyze the dynamic characteristics of automatic balancer. It is found from simulation and experimental results that the automatic balancer suppress the steady state vibration of washing machine effectively. The test results match with the simulation results of ADAMS, thereby the dynamic model of ADAMS can be used as virtual prototype to predict the vibration characteristics which could be changed by the modification of design variableand can reduce the design cycle sharphy. To maximize the balancing effect of automatic balancer, the friction between balls and race and the deviation between geometric center and rotation center of drum need to be minimized and the optimum design for the stiffness of flange shaft and the angular acceleration of drum should be achieved.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.664-669
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• 2000

Angular misalignment is one of the important causes for shaft vibration of turbine-generator in 1000MW nuclear power plant. It may cause the plant unexpected shutdown and subsequent accident. The change of dynamic characteristics in journal bearing and rotor due to angular misalignment in high pressure turbine is analyzed. The stiffness/damping coefficients of journal bearing increase as angular misalignment. Subsequently the natural frequency of HP turbine is changed. It was found that the natural frequency may locate near 2 times operating frequency in case of severe misalignment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1286-1291
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• 2000

A new electro-rheological squeeze film damper (ER SFD) has been sealed with slotted piston rings which have electrodes at the inside of the constant gap. The slotted ER SFD can prevent the problem of electric discharge which might be occurred in the previous configuration of an ER SFD. The current paper presents the extraction of linearized dynamic coefficients within small orbit where these coefficients are controlled by the application of electric strength. Test rig has been modified to isolate the damper section for dynamic coefficient extraction. The results show that rotordynamic coefficients, damping and inertia terms, increase with increasing supply voltages, while stiffness coefficients decrease with increasing supply voltages. Rotating speed of rigid Shaft does not affect these coefficients.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.17 no.1
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• pp.35-40
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• 1981

This pape presents a study of stability of the two mass rotor with limited power similar to that employed by Kononenko and also presents a study on the digital computer to obtain the unstable region of the ;'ot::r oyer two critical speed ranges. The unstable region is identified by studying the Routh-Hurwitz criterion of the chc.rc.cteristic equation. The results are presented in two and three-dimensional diagrams to show how the various parameters affeCt the unstable region.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.1
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• pp.1-9
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• 2004

In this paper, an efficient modeling method of Horizontal-Axis Wind Turbine(HAWT) system is proposed. This method Is based on representing a HAWT system as a multi-body system with several rigid bodies i.e. rotor blade, low/high speed shaft, gear system, md generator. Also, simulation software WINSIM is developed to evaluate performance of wind turbine system. Simulation results show that the proposed modeling method and simulation software are efficient and reliable.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.170-173
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• 2002

A variable speed wind turbine simulator is designed and implemented for the simulation of wind power generation system. The control algorithm decides the shaft torque delivered to generator taking into consideration the wind speed, the generator rpm, and the rotor blade inertia. It is shown that the proposed control algorithm can emulate the dynamic behavior of actual wind turbine through simulations and experimental.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.1
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• pp.48-55
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• 2003

Hidden Markov Model(HMM) has a doubly embedded stochastic process with an underlying stochastic process that can be observed through another set of stochastic processes. This structure of HMM is useful for modeling vector sequence that doesn't look like a stochastic process but has a hidden stochastic process. So, HMM approach has become popular in various areas in last decade. The increasing popularity of HMM is based on two facts : rich mathematical structure and proven accuracy on critical application. In this paper, we applied continuous HMM (CHMM) approach with AR coefficient to detect and predict the chatter of lathe bite and to diagnose the wear of oil Journal bearing using rotor shaft displacement. Our examples show that CHMM approach is very efficient method for machine health monitoring and prediction.

• Journal of KSNVE
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• v.10 no.6
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• pp.1029-1034
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• 2000

A new electro-rheological squeeze film damper (ER-SFD) has been sealed with slotted piston rings which have electrodes at the inside of the constant gap. The slotted ER-SFD can prevent the problem of electric discharge which might be occurred in the previous configuration of an ER-SFD. The current paper presents the extraction of linearized dynamic coefficients within small orbit where these coefficients are controlled by the application of electric strength. Test rig has been modified to isolate the damper section for dynamic coefficient extraction. The results show that rotordynamic coefficients, damping and inertia terms, increase with increasing supply voltages, while stiffness coefficients decrease with increasing supply voltages. notating speed of rigid shaft does not affect these coefficients.