• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.05a
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• pp.41-45
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• 2006

The study on laser-ablation plasmas has been strongly interested in fundamental aspects of laser-solid interaction and consequent plasma generation. In particular, this plasma has been widely used for the deposition of thin solid films and applied to the semiconductors and insulators. In this paper, we developed and discussed the generation of carbon ablation plasmas emitted by laser radiation on a solid target, graphite. The progress of carbon plasmas by laser-ablation was simulated using Monte-Carlo particle model under the pressures of vacuum, 1 Pa, 10 Pa and 66 Pa. At the results, carbon particles with low energy were deposited on the substrate as the pressure becomes higher. However, there was no difference of deposition distributions of carbon particles on the substrate regardless of the pressure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.05a
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• pp.15-19
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• 2006

A pulsed laser ablation deposition (PLAD) technique is an excellent method for the fabrication of amorphous carbon (a-C) films, because it can generate highly energetic carbon clusters on a substrate. This paper was focused on the understanding and analysis of the motion of C particles in laser ablation assisted by Ar plasmas. The simulation has carried out under the pressure P=50 mTorr of Ar plasmas. Two-dimensional hybrid model consisting of fluid and Monte-Carlo models was developed and three kinds of the ablated particles which are carbon atom (C), ion ($C^+$) and electron were considered in the calculation of particle method. The motions of energetic $C^+$ and C deposited upon the substrate were investigated and compared. The interactions between the ablated particles and Ar gas plasmas were discussed.

• Transactions on Electrical and Electronic Materials
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• v.13 no.6
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• pp.301-304
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• 2012

Epoxy/microsilica (65 phr)/nanosilica (0~5 phr) composites (EMNC) were prepared in order to develop a high-voltage insulation material, where phr means parts per hundred relative to the epoxy oligomer. Tensile and flexural tests of the composites were carried out, and the AC electrical breakdown strength was measured, after which all the data were estimated by Weibull statistical analysis. As the nanosilica content increased, the tensile strength increased, and the highest value was 117.7 MPa in the EMNC system with 3 phr nanosilica, which was ca. 10% higher than that of the system without nanosilica. The value then decreased after 3 phr. The flexural strength and AC electrical breakdown strength showed the same tendencies as the tensile strength. The highest value of the flexural strength was 184.6 MPa in the EMNC system with 3 phr of nanosilica, which was ca. 15% higher than that of the system without nanosilica. The strongest value of the AC electrical breakdown strength was 79.0 kV/0.5 mm in the EMNC system with 3 phr of nanosilica, which was ca. 34% higher than that of the system without nanosilica.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.2
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• pp.232-238
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• 2013

In this paper we describe the maximum energy transfer of CSA(Capacitive Switching Antenna). CSA which is radiated antenna system contain energy storage and switch, antenna needs to high voltage source for electrical field radiation experiment. In this experiment we employed Marx generator as a charging source. CSA can radiate electrical field more efficiently by varying antenna capacitance. The electromagnetic generation system which was using CSA has some advantages which are more simple and more effective compared to exist system. We evaluated the performance of electromagnetic wave generating system using CSA. As a result UWB gain of system is 0.47, It is higher level than exist system is 0.3. Radiated electrical field strength at 1m is 70kV/m. It is measured by D-dot sensor and gap distance is 20mm. Center frequency of CSA is approximately 25MHz. When vary the antenna gap distance from 50mm to 20mm, we can find the radiation field strength is decrease and antenna center frequency is increased. We also simulated the energy transfer efficiency to compare with experiment result. Consequentially, CSA needs to appropriate capacitance which is similar value from marx generator for maximum energy transfer, and gap is less than 1mm to increase the CSA capacitance.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2092-2093
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• 2008

Since Jan. 2004, the Ministry of Construction and Transportation has partly introduced estimation system of historical cost data in order to reflect result cost of construction market to cost estimation for public construction. And KEPCO started estimation system of historical cost data in the electrical construction works. Electrical construction cost index a matter of great importance. This paper was conducted to examine estimation methods of the items of the price index estimation system of historical cost data and suggest reasonable applications.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.115-122
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• 2010

The main purpose of centralized monitoring system is to manage factory electrical installation efficiently by on-line data acquisition and supervisory control. The existing centralized system is only able to be managed by operator whenever electrical installation's faults are detected. Therefore, it may be possible for propagating the installation's faults when operator make the unexpected mistakes. To overcome the unexpected mistakes, in this paper, the author presents a centralized monitoring system for factory electrical installation using active database. by using active database production rule, stated system can minimize unexpected mistake and can operate centralized monitoring system efficiently. Test results on the five factory electrical installations show that performance is efficient and robust.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.3
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• pp.45-52
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• 2009

Power line communication or power line carrier (PLC) is a system for carrying data on a conductor and can also used for electric power transmission. Now the powers used in the motor drive system are mostly DC sources. Even AC powers in some systems are generated from DC sources by the inverter. It is can be forecasted that the DC-link PLC technology will be widely used in various industrial fields. In this paper a novel BLDC motor control system using ASK DC-link PLC technology is proposed. The characteristic of this system is that the communication only needs 2 DC lines and there are no additional lines to translate the reference signals. The number of signal cables can be minimized when the DC-link PLC method is applied in the multi motor control system and the slip ring design also can be simplified when this method is applied in rotation machines. The proposed motor control system is clarified by the PSIM and MATLAB simulations and tested through the hardware prototype.

• Journal of Electrical Engineering and Technology
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• v.3 no.4
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• pp.484-490
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• 2008

In this paper, an integrated fault section detection and isolation strategy is proposed based on the application of the Distribution Automation System(DAS) utilizing advanced IT and communication technologies. The Feeder Remote Terminal Unit(FRTU) has been widely used to collect data in the Korean distribution system. The achieved data is adopted in this method for detecting multiple fault types. Especially in the case of single phase-to-ground fault, the fault section is detected by comparison of the zero-sequence current phase angle. The test results have verified the effectiveness of the proposed method in a radial distribution system through extensive simulations in Matlab/Simulink. Furthermore, a communication-based demo system identical to the simulation model has been developed, and it can be applied as an online monitoring and control program for fault section detection and isolation.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.85-86
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• 2015

This paper is to study the inverted pendulum system of cart type by using the method of PID control. This system is that inverted pendulum maintain a constant balance from unstable state by moving a cart. It is controlled via the PID controller. PID controller is proposed to maintain a constant balance for nonlinear system such as the inverted pendulum system so PID control is widely used in the industrial field because of superior control performance, easy implementation and relatively simple structure. To design this system, it consist of Encorder and DC motor. Encorder is used to read the angle of the pendulum and DC motor is used to change the angle. We can verify results of experiment through the Matlab simulator via the inverted pendulum system of cart type.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.4
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• pp.350-357
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• 2005

This paper presents a mechanical sensorless vector-controlled system with parameter identification by the aid of image processor. Based on the flux observer and the model reference adaptive system method, the proposed sensorless system includes rotor speed estimation and stator resistance identification using flux errors. Since the mathematical model of this system is constructed in a synchronously rotating reference frame, a linear model is easily derived for analyzing the system stability, including motor operating state and parameter variations. Because it is difficult to identify rotor resistance simultaneously while estimating rotor speed, a low-accuracy image processor is used to measure the mechanical axis position for calculating the rotor speed at a steady-state operation. The rotor resistance is identified by the error between the estimated speed using the estimated flux and the calculated speed using the image processor. Finally, the validity of this proposed system has been proven through experimentation.