• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.653-657
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• 2005

The commercial contract was made firstly in the world for one set of high temperature superconducting(HTS) cable system between buyer, Korea Electric Power Research Institute and seller, Sumitomo Electric Industries, Ltd. in August 2004. After fabrication, test and examination, the HTS cable system will be installed at the KEPRI's test field in Gochang, Jeonbuk province from the time of July 2005. KEPRI is preparing measurement and test facilities for field test of the HTS cable system and carrying out researches into the design and construction of superconducting cable test building, evaluation of cooling performance, measurement of AC loss, analysis of the quench phenomena due to excess current and means of linking the HTS cable system to the existing electric power supplying system. The constitution of, the method to install and the plan of test operation of the HTS cable system will be presented in this paper.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 봄 학술발표회 논문집
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• pp.215-222
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• 2000

The reinforced roadbed should have the ability to spread out the load intensity lower than the bearing capacity of the subgrade of track structure as well as to prevent the softening of roadbed by providing appropriate stiffness in the roadbed, thus fully supports the track structures. Full scale reinforced roadbeds with several different types of monotoring sensors was also constructed to evaluate the performance of each reinforced roadbed through the continuous monitoring while the train operation. In this study, Field tests such as PLT, SASW were also carried out at each reinforced roadbed. The results of the field and lab tests, installation and calibration of sensors, as well as construction condition of the reinforced roadbed are presented.

• 복합신소재구조학회 논문집
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• 제1권1호
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• pp.34-45
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• 2010

This paper describes the design, manufacturing process, testing, application, and assessment of capacity-ratings of the first all advanced composites bridge on a public highway system. In order to verify the bridge design prior to the field application, a sub-scale bridge superstructure was built and tested in the laboratory. The field load test results were compared with those of the finite element analysis for the verification of validity. To investigate its in-service performance, field load testing and visual inspections were conducted under an actual service environment. The paper includes the presentation and discussion for advanced composites bridge capacity rating based on the stress modification coefficients obtained from the test results. The test result indicates that the advanced composites bridge has no structural problems and is structurally performing well in-service as expected. Since these composite materials are new to bridge applications, reliable data is not available for their in-service performance. The results may provide a baseline data for future field advanced composites bridge capacity rating assessments and also serve as part of a long-term performance of advanced composites bridge.

• 조명전기설비학회논문지
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• 제24권4호
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• pp.57-65
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• 2010

본 논문에서는 한국 지형에 적합한 지상파 ATSC DTV용 채널 모델을 제시하였다. 이를 위해 지상파 DTV 방송과 관련된 기존 전파 모델을 연구하고, 한국방송공사에서 실시한 지상파 DTV 방송 필드테스트의 실측 데이터를 분석하였다. 실제 측정한 전계강도를 기반으로 제시한 채널 모델은 기존의 전파모델에 비해 더 정확한 값을 가진다. 제시한 채널 모델은 지상파 DTV 시스템 실행시 요구되는 link budget 계산에 유용할 것이다.

• 조명전기설비학회논문지
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• 제28권5호
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• pp.39-51
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• 2014

This paper deals with design of a direct-coupled, small-scaled permanent magnet generator (PMG) for wind power application. First, this paper determines rated power and speed of the PMG from measured characteristics of wind turbines. Second, we derive analytical solutions for the open-circuit field in order to determine optimum magnet thickness and pole pitch/arc ratio. Third, on the basis of open circuit field solutions, stator magnetic circuit including slot opening, teeth width and yoke thickness is designed. And then, a diameter of stator coil which agree with a required current density is calculated, and its turns are determined from the area of slot considering winding packing factor. Finally, finite element (FE) method is employed in analyzing the details of the designed PMG and, test results such as back-emf measurements are given to confirm the design.

• 한국지반공학회논문집
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• 제25권7호
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• pp.55-64
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• 2009

본 연구에서는 실제 현장조건을 고려하여 토목섬유의 화학저항성을 측정하기 위한 개선된 시험방법이 제안되었다. 이를 위하여 시공조건에 가장 근접한 시험법을 규격화하기 위한 인덱스 및 성능시험이 실시되었으며, Arrhenius 식에 의한 가속모델을 적용하여 실험 데이터를 해석하였다. 전반적인 실험 결과를 분석, 비교하여 현장 시공조건에 부합한 개선된 토목섬유의 화학저항성 시험방법을 확립하고 그 가능성을 제시하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 춘계학술대회 논문집
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• pp.502-505
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• 2004

The purpose of this experiment is to modify diagnosis criterion of isothermal relaxation current(IRC) measurement equipment which is using for distribution cable diagnosis. We're using this system for several years in the field instead of DC leakage current measurement and lots of cables were replaced. But we have to investigate on the reliability of this equipment for our cables because we didn't carried out condition assessment of extracted cables after field diagnosis by this equipment. It is important thing for cable maintenance. If the replacement criterion is improper we can not prevent failures or will waste budget on account of replacement of the sound cables. In this papar we selected field installed cables and injected silicone fluid to the cables for insulation rehabilitation. In order to prove reliability of the diagnosis equipment we compared diagnosis results and AC breakdown strength according to operating time after silicone treatment. This is the results of the field test for 1 year.

• 조명전기설비학회논문지
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• 제21권9호
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• pp.64-75
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• 2007

Photovoltaic systems utilize the infinite clean energy of the sun, without creating any air pollution or noise and mechanical vibration. A PV system operates without the need of fuel, rotation surfaces, high temperatures or high pressures. It is therefore to do maintain and simple to install as well as having a long life cycle. The global market for PV systems continues to grow rapidly by 30[%] per year. This paper suggests a new design method for the PV system installation that will allow to the improvement of system efficiency. This method is in accordance with the loss parameter compensation method designed for the PV systems and investigated through simulation and practical experimentation. It was applied to an interconnected 10[kW] grid PV system and was demonstrated in the field. Features such as solar array, PCS, system efficiency, performance and stability were considered. Through the proposed optimal parameter design method, the features of the system were studied, and the 10[kW] PV system was demonstrated and analyzed.

• 한국산학기술학회논문지
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• 제16권8호
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• pp.5513-5521
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• 2015

국내의 저밀도 지선 구간에 적용되고 있는 지상 설비들은 주요 노선과 유사하게 설치되고 운영됨에 따라 운영 효율성 측면에서 적합하지 않은 문제를 가지고 있다. 이에 따라 열차의 안전과 운영 효율성을 도모하기 위해 개발된 차상중심 열차제어시스템은 고가의 지상신호 제어장치 없이 안전한 운행이 가능하도록 한다. 이러한 차상중심 열차제어시스템은 차상제어시스템, 선로변제어시스템, 운행관리시스템으로 구성된다. 본 논문에서는 현장에 차상제어장치와 선로변제어장치를 설치하여 적합성 시험을 비롯하여 통신 및 인터페이스 시험 수행 내용을 기술한다. 설치 검사는 전원, 전압, 케이블 연결, LED 상태 확인 등을 포함한다. 이를 바탕으로 실제와 유사하게 선로전환기, 건널목차단기를 포함한 가상노선에서 다양한 시나리오에 따른 동적 운영 시험을 통해 개발된 시스템의 현장 적용성을 검증한다. 총 7가지 시나리오에 대하여 동적 운영 시험이 수행되었고, 각 시나리오별로 여러 번 시험을 반복하였다. 메인 프로세스 로그를 분석하여 동작별 경과 시간을 계산하였으며, 대부분 수 초 이내에 동작이 이루어짐을 확인하였다. 또한 공인기관 입회하의 현장시험을 통하여 개발된 시스템을 검증하였고 시험성적서를 발급받았다.

• 조명전기설비학회논문지
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• 제29권11호
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• pp.41-46
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• 2015

This study was conducted to discover a substitute of $SF_6$ gas. $SF_6$ gas is widely used across the industries. Thanks to superior electrical properties, in particular, it has been commonly used in electrical industry. However, there have been a lot of studies on its serious effect on global warming. As a substitute of this synthetic gas, a mixture of dry air and $N_2/O_2$ was chosen in this study. In case of $N_2/O_2$, dielectric strength differs depending on the mixing ratio. This study examined dielectric breakdown and flashover after adjusting oxygen percentage in the dry air. This test was conducted in a quasi-uniform electric field depending on pressure, oxygen concentration and gas mixtures. The test results found that dielectric voltage and flashover voltage were the highest at a certain oxygen concentration. It is the results of this photoionization and electron attachment of oxygen.