• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2006년도 추계학술대회 논문집
• /
• pp.1436-1441
• /
• 2006

In this paper, Computer-aided Maintenance Equipments, which are being used in High Speed Line Train Control System, are applied to analyze failures in train control systems, resulting in long time delays of trains. It can be expected to extend and apply CAMS(Computer Aided Maintenance System) in the hereafter efficient operation and maintenance of high speed railway train control systems, by comparison between the analysis result of fundamental causes, from high speed railway train control system failure occurred during the operational process, and predictive result of failure causes, based on the recording data of CAMS when failures were occurred.

• KSBB Journal
• /
• 제4권2호
• /
• pp.118-122
• /
• 1989

Candida utilis를 model균주로 하여 세포증식과 기질소모를 on-line 간접측정하고자 개인용 컴퓨터(IBM PC-AT)와 interface된 quadrupole mass spectrometer로 발효 배기가스를 분석하였다. 5분마다 연속적으로 분석되는 질소, 산소, 이산화 탄소 및 수증기의 mole백분율(%)로부터 산소 소비속도(OUR)와 이산화 탄소 발생속도(CER)를 on-line으로 계산하였다. 미리 실험 결과치로부터 결정한 maintenance와 수율 상수들($k_1k_2 $ 값을 이용하여 세포농도와 기질인 포도당의 농도를 on-line으로 간접추정하였다. 간접추정된 값들은 실험적으로 측정한 세포농도 및 기질농도와 잘 일치함을 알 수 있었다.

• 전기학회논문지
• /
• 제66권4호
• /
• pp.727-732
• /
• 2017

This paper describes the dynamic characteristics depending on installation condition between a pantograph and an OCL (Overhead Contact Line) on a new high speed line in Korea. The current collection performance between the pantograph and the OCL was tested during train operation from Suseo to Jije stations. The current collection performance is evaluated based on the duration of an arc by using an arcing measurement system. The system consists of an optical sensor for measuring the duration of an arc and a camera for monitoring current collection performance. An arcing duration is defined as a percentage of arcing in international standards. This test aims to analyze the locations of repetitive arcing depending on installation conditions of OCLs on a new high speed line in order to use the result as reference data for correct construction and maintenance.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2010년도 하계학술대회 논문집
• /
• pp.109-109
• /
• 2010

On-line partial discharge(PD) diagnostic system is the most prominent systems to diagnose insulation condition for the high voltage rotating machines. Partial discharge measuring system(PDMS) series with ceramic coupler(PD detecting sensor) installed hydro generator and high voltage motor have been measured the PD data for many years. The trend of PD magnitude in the on-line PD system increased for some machines. These machines showed a same result in the conventional off-line PD test and PD magnitude decreased after stator winding insulation cleaning. This case study show that PDMS has been proved to be good results by comparing PD magnitude with on-line and off-line PD test and it is important to plan the maintenance project for the hydro generator stator winding because PD value was decreased after insulation cleaning.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2002년도 춘계학술대회 논문집
• /
• pp.213-218
• /
• 2002

A new German high speed railway slab track was investigated. The construction objective was to provide a durable and maintenance free track system consisting of precast concretepanels of consistently high quality and highest achievable accuracy in track geometry. The System on the basis of precast panels similar to the slab track system constructed on the line Dachau- Karlsfeld in 1997.

• 한국철도학회논문집
• /
• 제11권3호
• /
• pp.334-341
• /
• 2008

자갈궤도는 압축성 재료인 자갈과 흙을 기초로 하여 건설되므로 공용 기간 중 승차감을 확보하고 수명연장을 위해서는 유지보수작업이 필수적이다. 현재 수행되고 있는 자갈궤도에 대한 유지보수 작업은 EM120 검측차를 이용한 궤도틀림 측정 결과로부터 결정된다. 궤도틀림은 궤도에 변형이 발생된 결과를 측정하는 것으로, 궤도틀림을 유발시키는 근본적인 원인을 평가해 볼 필요가 있다. 본 연구에서는 궤도틀림의 원인이 궤도를 지지하는 도상과 노반에 있다고 판단하고, 도상 및 노반의 싱태를 평가할 수 있는 비파괴탐사법 (GPR4과 PFWD)을 개발하고 이를 경부선 500m구간에 적용하였다. 개발 작용된 방법은 층 두께 평가법과 궤도수직강성 평가법 및 도상 노반 시추법이다. 도상 및 노반 상태평가 결과를 기 수행된 궤도틀림 검측결과 및 유지보수작업과 비교함으로서 불필요한 유지보수작업 구간을 평가하였다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 춘계학술대회 논문집
• /
• pp.899-904
• /
• 2007

Improvement projects has been progressed for railway electrification and double track line in the conventional line as well as high speed line for the high speed and large transportation capability of railway. Especially, many variable operation plans are possible such as interaction between high speed line and conventional line and operation of tilting train due to the electrification of the conventional line. Railway electrification is more energy efficient and environmentally-friendly, but it has some problems such as an enormous initial construction and maintenance costs and electrical accidents. Therefore, the more intensive research will be progressed about railway electrification effectiveness for the continuous electrification project. So, we analyzed railway electrification effectiveness about the energy side using annual operation data of electric car and diesel car. The energy side was divided into energy costs and national energy consumption for analyzing electrification effectiveness about entire line and specific line. We verified advantage of energy costs and national energy consumption in this paper and this result will contribute to the progress of the continuous electrification project and the more efficient operation ways in electrification line

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.208-211
• /
• 2003

The western route of KEPCO's 765 kV transmission line has been tentatively operating as 345 kV voltage before commercial operation. KEPCO decided to operate the 765 kV line for commercial operation after completing the test operation of 765 kV substation in 2002. In the process of energizing the line as 765 kV voltage, double circuit transmission line will be operated with two voltage grades of 765 kV and 345 kV. As the earthing switches are installed on both ends of the line, electrostatic induction voltage and electromagnetic induction current were calculated prior to the line energizing in order to confirm the ratings. The induced voltage and current are important for the maintenance of the parallel circuit. This paper presents the simulation results of electrical phenomena such as electrostatic induction voltage and electromagnetic induction current from the parallel line. The transmission line was modeled by EMTP (Electro-Magnetic Transient Program). The simulation results were compared with the measured results at the field.

• 한국구조물진단유지관리공학회 논문집
• /
• 제16권5호
• /
• pp.148-160
• /
• 2012

본 연구에서는 콘크리트 구조물의 합리적인 압축강도 및 탄산화 예측식을 제안하고, 이 제안식의 현장적용을 통한 보다 효율적인 터널 진단 및 유지관리 기법을 개발하였다. 이를 위하여 공용연수가 약 30년 이상 경과하였으며, 약 15년 동안 수회에 걸친 진단 및 점검으로 무수히 많은 현장 내구성 측정 데이터가 축적된 서울메트로를 대상 시설물로 선정하였다. 압축강도 및 탄산화 분석결과 80% 이상의 정확도를 확보하는 각각의 예측식을 도출하였으며, 기존 제안식과의 비교분석을 통하여 본 연구 제안식의 신뢰도를 확인하였다. 또한 제안식의 현장적용 결과 압축강도 및 탄산화 깊이에 대한 예측치의 평균오차율이 약 20%내외로서 80% 이상의 높은 정확도를 확보하는 것으로 분석되어 현장적용의 적합성을 확인하였다. 현장조사 전 내구성 예측 맵(Map)을 활용한 효율적인 유지관리 기법을 개발하였다. 예측 맵(Map) 활용 시 진단기술자 및 시설물 담당자는 설계기준강도에 미달되거나 탄산화로 철근부식 가능성이 높은 취약부위를 한 눈에 파악할 수 있으므로 일일이 조사를 수행하는 과정에서 취약부위를 도출해야 하는 현 조사기법 보다 효과적으로 터널 조사 및 유지관리를 수행할 수 있을 것으로 기대된다.

• 드라이브 ㆍ 컨트롤
• /
• 제9권2호
• /
• pp.28-38
• /
• 2012

Monitoring of system cleanliness levels and counting of particulate contaminant are fundamental to achieving hydraulic system reliability as any departure from the specified cleanliness level is often a precursor to future failures. On-line monitoring of cleanliness levels has the advantage of giving data both very quickly and accurately as environmental influences are eliminated. In this way, corrective actions can be promptly implemented. Most on-line instruments are sensitive to system conditions to a greater or lesser extent, but Automatic Particle Counters (APCs) working on light extinction principles are especially sensitive to the presence of optical interfaces caused by such conditions as fluid mixtures, emulsions, free water and air bubbles. These conditions give erroneous data and can result in drawing incorrect conclusions, wasting maintenance time and ultimately, reduced user confidence in cleanliness monitoring. This paper describes such conditions and shows how the correct selection of the analysis technique can result in reliable cleanliness level data.