• KIEE International Transactions on Power Engineering
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• v.4A no.2
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• pp.84-90
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• 2004

This paper presents a new method for choosing the best line for transmission system expansion planning considering the highest reliability level of the transmission system. Conventional methodologies for transmission system expansion planning have been mainly focused on economics, which is the minimization of construction costs. However, quantitative evaluation of transmission system reliability is important because successful operation and planning of an electric power system under the deregulated electricity market depends on transmission system reliability management. Therefore, it is expected that the development of methodology for choosing the best lines considering the highest transmission system reliability level while taking into account uncertainties of transmission system equipment is useful for the future. The characteristics and effectiveness of the proposed methodology are illustrated by the case study using a MRBTS.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1102-1103
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• 2015

The researchers worldwide have been trying to apply high temperature superconducting wire for power system devices. High voltage direct current (HVDC) transmission system has been used for bulk and long-distance power transmission. The authors designed a laboratory-scale superconducting DC transmission line to investigate its applicability to an HVDC system. The superconducting DC transmission line was simulated in connection to a laboratory-scale HVDC system using PSCAD/EMTDC. The operating characteristics of the superconducting DC transmission line connected to HVDC system and the effects of the superconducting DC transmission line on HVDC system were analyzed and compared with the results of a conventional DC transmission line. The results of operating characteristics for the superconducting DC transmission line were discussed in detail.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.718-719
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• 2011

Lately, the demand for electrical power has been significantly increased. As a result a power transmission system has been improved. On the other hand fault current increased more than past. Superconducting fault current limiter (SFCL) is one of the solutions to limit fault current. However, SFCL's research has not advanced in a power transmission system fully. Therefore, we studied effect of SFCL in a power transmission system. The power distribution system is open-loop circuit, but a power transmission system is closed-loop system. Consequently, Fault current in a power transmission system is larger than fault current in a power distribution system. we exerimented a simple closed-loop power transmission system circuit.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.1
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• pp.34-43
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• 2009

In this thesis, we explain developing processes of the power transmission system for lift truck. Conventional power transmission system had some problems such as spatial constraints or low speed and high torque problem. Because conventional power transmission system was mainly designed for high speed vehicles. In this paper we developed power shift drive axle specialized for $2.0{\sim}3.5$ ton lift truck. Innovative structure of transmission which is built in inside axle, enables to reduce system weight and size by 40% compared to the conventional power transmission system. Also, it is possible to do additional functions such as auto parking system and anti-roll back system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.1
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• pp.35-45
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• 2013

Owing to the increase in the penetration of distributed generation the DGs connected to the distribution system have an effect on the system conditions of the transmission system and neighboring distribution systems. This makes the separate analysis of the transmission and distribution system no longer valid and requires the consideration of both the system in the analysis process. This paper proposes a transmission/distribution integrated analysis hybrid algorithm that would ensure the accurate analysis of the system by reflecting the results of the transmission and distribution system analysis on each other. Different scenarios are being analysed in order to verify the effectiveness of the hybrid algorithm by observing the effects of the DG connected distribution system on the transmission system and neighboring distribution systems. The algorithm and simulations performed are being conducted by MATLAB and the IEEE 30 bus system and a test distribution system has been utilized for the transmission and distribution systems respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.10
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• pp.829-841
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• 1990

On assuming that the transmission speed of the original information is the fifth-order transmission speed of the Korea digital multiplex hierarchy (564.992Mb/s), this paper proposes a new structure of the transmission line frame at the terminal repeater system, in order to not only maintain and conserve 565Mb/s optical fiber transmission system but also make the B.S.I. of digital communication network for the optical transmission. And the structure uses the mBIZ transmission line code, which is considered the optimal transmission line code of conventional transmission line codes. System hardware of the transmission line frame structure proposed in this paper is consisted by a method of pulse stuffing after converting the speed of the original information signal sequence at the terminal repeater system for 565Mb/s optical transmission. As a result of this, we can prevent the optical transmission system from a domino phenomenon, the phenomenon of the continuous error multiplication of systems by the transmission error, and suppress timing jitter and the identical consecutive digit number. And also we can improve SNR of the optical transmission system about 2dB because of raising total BER at the optical terminal system up to 10.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1841-1848
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• 2010

Electric railway system consist of rolling stock, track, signal and streetcar line system. ATP(Automatic Train Protection) system in railway signaling system is the important one grasping the position and velocity of a train. The wayside transmitter of ATP system is installed between rails. Recently, the research about increasing train speed has been developed in total departments of the railroad systems. The study on the information transmission between on-board transmitter and wayside transmitter is required for increasing the train speed in the ATP system. When the train speed is increased as to same transmissi on distance, the problem on information transmission occurs because the transmission time is decreased. In case that the transmission distance is extended, the transmission time is decreased with respect to the train speed. Therefore, we have to define the standard magnetic intensity as to the train speed in order to transmit correctly telegram. In this paper, the transmission distance for the telegram is suggested on the basis of the train speed. Also, the standard magnetic intensity from the wayside transmitter to on-board transmitter is proposed by using transmission distance regarding the train speed in the ERTMS/ETCS system by using Matlab program.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.397-399
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• 2000

This paper presents a method for assessing reliability indices of transmission system. Because successful operation of electric power under the deregulated electricity market depends on transmission system reliability management, quantity evaluation of transmission system reliability is very important. The key point idea is based on that the reliability level of transmission system is equal to reliability level difference of between composite power system(HLII) and generation system(HLI). It is sure that risk indices of reliability of composite power system are larger than those of generation system. It is the reason that composite power system includes uncertainties and capacity limit of transmission lines. The characteristics and effectiveness of this methodology are illustrated by the case study using MRBTS.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.5
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• pp.445-458
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• 1992

As one of the forced cooling method of the underground power transmission system, external water cooled system with trough in tunnel was investigated. This study is performed on thermal analysis for a standard condition to determine the cable transmission current of the underground power transmission system about the cooling facility. A parametric study was performed for the inlet water temperatures, flow rates, the inlet air velocities, flow rates and the cooling spans. This study shows that the cable transmission current varies within the allowable limitation in compliance with the variation of inlet water temperatures and flow rates. It exhibits little variations for the most intervals in compliance with the variation of inlet air temperatures and flows. But, the cable transmission current fast reduces for a specified interval and consequently affects the underground transmission system. As a result, when the actual forced cooling system is designed, the design conditions of inlet air have to be considered as the most important parameters in determination of the cable transmission current.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.12a
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• pp.271-274
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• 2001

Recently, most vehicles has the Automatic transmission system as their transmission system. The automatic transmission system operates with fixed shift patterns. In the opposite of manual operation, it is easy and convenient for driving. Though these merit, the system can not evaluate the driver's intension because of usage of fixed shift pattern, To consider driver's intension, we must consider both the driving intensity of driver and the status of vehicle. In this paper, we developed flexible automatic transmission system by using the proposed moduled neural networks which can learn the status of the vehicle and driver's intensity As a result, we compare the transmission system using fixed shift pattern and the proposed transmission system and show the good performance in the change of shift position.