• Journal of the Korean Society of Industry Convergence
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• v.26 no.5
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• pp.813-823
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• 2023

In this study, microstructure, hardening layer hardness, and case depth were evaluated after induction hardening(IH) of base metal specimen(BM) treated with annealing and quenching-tempering specimen(QT) treated with quenching and tempering. The microstructure after IH was significantly influenced by the microstructure before IH and the induction coil heating movement speed, but the effect of the induction frequency was very small. The hardness of the hardened layer at an induction coil heating movement speed of 15 mm/s or less was more influenced by the microstructure before IH than the induction coil travel speed and induction frequency. The induction coil travel speed has the significantly effect on the case depth, the induction frequency has effect and the microstructure before IH has a small effect.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.04a
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• pp.359-364
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• 2006

This document analyses the empirical study result of the safety quality management system(SQMS) induction. This analysis is composed as the following. First of all, we take a brief look at (he present Korean situations after the SQMS induction. Next, we analyse the effect of the SQMS induction, then we indicate the conclusion, suggestion, limits and future course of this study. We divided the effect of induction in 21 factors. The result was 3.5 out of 5 perfect Points, which shows the high preference. Higher points were scored with international companies than domestic ones, the companies accepted before 1998 than the ones after 1998, and large enterprises than smaller ones.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.276-281
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• 2010

In this paper, an electromagnetic induction on a telecommunication line by the distribution line of a power provision system or a feeder line of an electrified railway system has been verified through experiments. The basic cause of induction occurrence by these practical power provision systems is the returning current through the earth. This principle has been confirmed by the experiments documented in this paper which implemented these mechanisms to incur an induction. Experimental methods were used to produce the returning current through the earth. The experiment to find a relationship between inducing strength and the distance between the two phase lines in a power provision line has also been included to confirm that, when the distance is enlarged, the induction effect increases as the cross-nullification effect of magnetic fluxes decreases. An experiment for the existence of a shielding effect by another conduction length material has been addedas a protection measure against the induction.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.5 s.182
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• pp.128-136
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• 2006

To predict the noise and vibration characteristics of induction motor system, it is necessary to develop the mathematical model including all the mechanical elements such as shaft, blower, rotor, fan, bearing, case and mounting parts. Coupling effect between case-mount system and rotor- shaft system including shaft, blower, rotor, fan and bearing is examined. Impact exciting experimentation was done in order to verify vibration model of the induction motor system. From experimental results, we can appreciate that the natural frequencies of induction motor system are in good agrements with analysis.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.90-94
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• 2004

In this treatise, The "Induction-Heating" and "The Skin Effect" which resulted from the High-Frequency using the High-Frequency Resonant Inverter are showed by this paper. It would research into "The Electro-magnetic Induction" and "The skin Effect" with an aluminum which is the typical paramagenetic metal. Ultimately, it was focused on the possibility of the heating for an aluminum sheet and draw up its practical use-plan.

• The Transactions of the Korean Institute of Power Electronics
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• v.11 no.3
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• pp.266-273
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• 2006

In difference with the rotary type electrical machinery, the single-sided linear induction motor(SLIM) that generates the direct thrust, is widely used for the operation system of electrified railroad, lope-less elevation system, conveyer system, and so on. The operational principle of single-sided linear induction motor is constructively similar to the general rotary Induction motor It Is difficult to realize the complicate linear induction motor which is applied space vector pulse width modulation(SVPWM) system, but widely used in vector motor control system or servo control system because of its high performance in current control. In this paper, we has modeled the dynamic characteristic analyzing methode, and calculated efficiently the end effect by using equivalent circuit methode in the operating linear Induction motor control system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.103-107
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• 2016

In general, the voltage stability of induction generator is lower than synchronous generator. Induction generator has a number of advantages over the synchronous generator on the side of price and maintenance. So Induction generator has been applied to the small hydroelectric power of low output. Induction generator usually generates a high current during grid connection. The high current that occurs during grid connection can cause a voltage drop in the system. In order to increase the supply of the induction generator, it is necessary to propose a method of reducing high current. This paper proposes some method of the soft start to reduce voltage drop caused by the large starting current. soft-start method has high voltage drop effect than direct start method, control of firing angle can be increased the voltage drop effect.

• 전기의세계
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• v.21 no.4
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• pp.7-14
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• 1972

The author has established a general equation for the travelling magnetic field in air gap with the end effect taken into consideration, which constitutes the basics for the analysis of characteristics of linear induction motor. This equation is verified by comparison of the experimental values with the theoretically calculated values. The properties of the travelling wave with attenuation, which is contained in the travelling magnetic field of linear induction motor, have been verified, and consequently the practicable equation is established with these effects taken into consideration. This provides the solid foundation for the theoretical analysis of the characteristics of the linear induction motor.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.6
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• pp.635-640
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• 2014

Detection and diagnosis of incipient bearing fault in an induction motor is important for the prevention of serious motor failure. This paper presents an analysis of the effect of a faulty bearing on the stator current of an induction motor. A bearing fault leads to torque oscillations which result in phase modulation of the stator current. Since the torque oscillations cause specific frequency components at the stator current spectrum to rise sharply, the bearing fault can be detected by checking out the faultrelated frequency. In this paper, a mathematical model of the load torque oscillation caused by a bearing fault is presented. The proposed model can be used to analyze the physical phenomenon of a bearing fault in an induction motor. In order to represent the bearing fault effect, the proposed model is combined with an existing model of vector-controlled induction motors. A set of simulation results demonstrate the effectiveness of the proposed model and represent that bearing fault detection using a stator current is useful for vector-controlled induction motors.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.399-403
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• 2005

In this paper, we analyze on the effect of RC filter to mitigate transient overvoltage on the high voltage induction motor fed by H-bridge cascaded 7-level inverter. The switching surge voltage becomes the major cause to occur the insulation failure by serious voltage stress in the stator winding of high voltage induction motor. The effect of switching surge appears more serious in high voltage induction motor than low voltage induction motor. Consequently, we demonstrated that the RC filter connected to the motor terminals greatly reduces the transient voltage stress md ringing. The results of simulation show the suppression of transient overvoltage at the motor end of a long cable. using EMTP