• Journal of Electrical Engineering and Technology
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• 제9권3호
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• pp.1002-1008
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• 2014

This paper describes insulation design and its reliability evaluation of ${\pm}80kV$ HVDC XLPE cable. Recently, the construction of HVDC transmission system, which is combined overhead line with underground cable, has been completed. This system is installed with existing 154 kV AC transmission line on the same tower. In this paper, the lightning transient analysis is firstly reviewed for selection of basic impulse insulation level and nominal insulation thickness. Then the electrical performance tests including load cycle test and superimposed impulse test based on CIGRE TB 496 are performed to evaluate the reliability of newly designed HVDC cable. There is no breakdown for ${\pm}80kV$ HVDC XLPE cable during electrical performance test. Finally, this system is installed in Jeju island based on successful electrical performance test (Type test). After installation tests are also successfully completed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.481-482
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• 2008

This investigation presents a method to design an optimal shape of a matching waveguide connecting two waveguides having different impedances. The design objective is to maximize power transmission through the waveguide system. When an incident wave impinges on an elastic waveguide system consisting of waveguides of different impedances, all of the incident wave power may not pass through due to the mechanical impedance. Therefore, the maximization of the transmitted power through a waveguide difficult to achieve without a systematic design method. In this work, the optimal shape design of a matching waveguide connecting two waveguides of different impedances is formulated as a shape optimization problem. If the material of the matching waveguide is given, its shape is the only parameter controlling the transmission power. Relatively simple one dimensional elastic wave transmission problems will be considered in this work, but the underlying methodology and the related physics can be clearly demonstrated. The influences of initial configurations as well as the target frequencies on the optimized shapes will be also investigated.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.249-256
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• 1998

Design target values of transmission loss in a high-speed train wall are suggested by calculating the difference between interior and exterior noise levels of it. Exterior noise level distribution on the boundary of train wall is calculated by Sysnoise, with sound source input prepared by experiments. Two kinds of exterior sound sources are considered, the rolling noise of train wheels on the rail and the aerodynamic noise from the pantograph. Interior noise level is provided by high-speed design target. Transmission loss characteristics according to the frequency band are examined.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.2016-2018
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• 2002

An exact solution of the lossy linear tapered transmission line is derived. As its application, a simple design method of the quasi non-distortion lossy linear tapered transmission line in the time domain is described. A design example is presented to show the validity and usefulness of the method.

• 한국기계가공학회지
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• 제14권2호
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• pp.1-6
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• 2015

Transmission of a tracked vehicle designed for multiple functions such as steering, gear-shifting, and braking is a core component of heavy vehicle to which the power is transferred based on combined technology of various gears, bearing, and fluid machineries. Robustness and durability of transmission, however, have been issued due to a large number of driving units and sub-components inside its body. The bevel gears are major components for the transmission of power in a transmission. Increasing the tooth surface roughness and chamfering of the bevel gears, especially, we aim to improve the quality of transmission. In this study, design structural evaluation is conducted on bevel gears of transmission for tracked vehicle using the ROMAX-DESIGNER program. By doing so, design safety of the bevel gears has been evaluated based on the gear strength theory of ANSI/AGMA 2003 B97 standard.

• 대한전기학회논문지:전력기술부문A
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• 제51권7호
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• pp.317-326
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• 2002

In this paper, a methodology for optimal PI supplementary controller using the modified genetic algorithm has been proposed to the oscillation damping in HDVC transmission system. These study processes are summarized as the formulation for load flow calculation in HVDC transmission system with SVC, the investigations on the basic control in HVDC system, the mathematical modeling for dynamic characteristics analyses, and the optimal design of MGA based PI controller generation the supplementary control signal of SVC. Its properties were verified through a series of computer simulations including dynamic stability. It means that the application of MGA-PI controller in HVDC transmission system can contribute the propriety to the improvement of the stability in HVDC transmission system and the design of MGA-OI controller has been proved indispensible when applied to HVDC transmission system.

• 한국자동차공학회논문집
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• 제4권1호
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• pp.63-74
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• 1996

Automatic transmission for heavy duty vehicles is a part of the power pack which includes steering and braking systems. This transmission in different from the one for passenger car. Therefore, in order to understand the trend of the important design parameters, maneuverability, acceleration performance and maximum speed, we need to analyze the total performance characteristics of the power transmission systems. In this study, modeling of the automatic transmission in heavy duty vehicle is carried out and the performance analysis method is presented. Results can be used for performance estimation data in the analysis for several combination method which determines the optimal parameters on the basis of penalty functions and weightings. And the estimation method of the important performance parameters such as engine inertia or power loss of engine by experiments is presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.719-720
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• 2007

Korea, for the first time in the world, constructed 765 kV double circuits transmission lines, which has 3 phases and 6 bundles with vertical arrangement using steel pipes in 1998. Also in 2002, we developed 765kV outdoor full GIS substation with self-developed technology. KEPCO accumulated a wealth of technologies for 765kV system construction and operation, and are listed 5th in technology field in the world. With this advanced technologies, we are developing oversea business. We started with a projects, 'Development Study on the Power System Network Analysis in Myanmar' in 2001, and continued the project to transmission design, consulting for transmission technology including the education of foreign trainees in south-east and middle east asia. Currently, 12 overseas businesses including 330kV transmission system consulting in Ghana, are in progress. In 2007, beginning with 750 kV transmission consulting in China, we are operating ATT(Advanced Transmission Technology) training program, which educate engineers of government and utilities company from China, Myanmar, Cambodia, Laos and Cambodia. However, for the successful development study on the power system, design of the power system and the training service, it is essential to standardize load design criteria in consideration of temperature, wind speed, air pressure and density, etc. of the other countries. Therefore, in this paper, standardized load design criteria for Cambodia, Laos, Myanmar is explained.

• 화약ㆍ발파
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• 제31권1호
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• pp.55-63
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• 2013

싱가포르 전력구 터널 건설공사는 싱가포르 내의 전력수요 증가에 대응하기 위해 지하에 400kV의 고압 전기 케이블 등 송전설비 설치를 위한 터널을 건설하는 공사이다. 본 전력구는 총연장 35km의 터널로서 18.5km의 North-South Line의 3개 공구 (NS1, NS2, NS3)와 16.5km의 East-West Line의 3개 공구 (EW1, EW2, EW3)로 나누어 건설된다. 총 6개의 공구 중 SK건설은 EW2 공구와 NS2 공구를 수주하여 현재 시공중이다. 본 프로젝트의 과업 중 지상과 고압 송전 케이블 터널을 연결하는 수직구가 공구당 3~4개소가 있으며, 시공 중에는 TBM 발진용으로 활용된다. 지하 전력구는 싱가포르 내 도심 한복판을 가로질러 건설되며, 수직구 또한 대부분 도심지 내에 있어 수직구 굴착 시 발파 효율의 극대화와 동시에 싱가포르 소음 및 진동 기준을 만족하는 최적의 발파 설계가 요구된다. 싱가포르 전력구 터널 EW2 공구의 수직구 발파는 현지 허용 진동속도기준을 준수하고 국내의 우수한 발파 설계기술을 적용하여 설계되었으며 본 설계를 통하여 국내의 우수한 발파 설계 및 시공 기술을 전파할 좋은 기회가 될 것으로 기대된다.

• 산업경영시스템학회지
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• 제34권4호
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• pp.66-71
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• 2011

This article proposes a novel shift automation mechanism for an automated manual transmission (AMT). The development of an automated manual transmission is currently being paid considerable attention by vehicle manufacturers, with the prospects of combining the comfort of an automatic transmission and the high efficiency of a manual transmission. In order to automate the shift mechanism of a manual transmission, the proposed shift automation mechanism consists of two electric motors, cross shaped pinion gears, rack type shift rails, and a ball splined hollow shaft. First we describe the shift mechanism and operating principles of a manual transmission to investigate important design criteria for the shift automation device. And a new shift automation mechanism is described with its structure, elements, and operating principles in detail. Using a conventional manual transmission, we develop a full three-dimensional CAD model of an AMT which includes main components of the manual transmission and the designed shift automation mechanism. Finally we investigate the operating performances and feasibility of the designed AMT by a dynamic analysis.