• Journal of Mechanical Science and Technology
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• 제20권4호
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• pp.482-493
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• 2006

The carbody structure of a high speed train passing through a tunnel is subjected to pressure fluctuation. Fatigue strength of the carbody structure against the fluctuating pressure loading should be proved in the design stage for safety. In this study, to get the useful information on the pressure fluctuation in the tunnel, measurement has been conducted during test running of KHST on the high speed line for two years. The measured results were analyzed and arranged to be used for carbody design. A prediction method for the magnitude and frequency of pressure change was proposed and the propagating characteristics of pressure wave was investigated. By statistical analysis for the measured results, a pressure loading spectrum for the high speed train was given. The proposed method can also be used to estimate the pressure loading spectrum for new high speed line at design stage combined with the results of train performance simulation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.448-451
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• 2003

For this research, we developed the hardware and software of the measurement system for on-line test and evaluation. The software controls the hardware of the measurement data and acts as interface between users and the system hardware. In this paper, we is studied for temperature measurement of main transformer. In order to this test is developed measurement system. Using this system, we obtained important result for main transformer temperature.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1415-1419
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• 2004

It is essential to evaluate harmonic characteristics of high speed train using power electronics equipment such as converter-driven motor drives, battery chargers and auxiliary power supplies. The purpose of this study is to measure and analyze harmonics characteristics of korea high speed train prototype. This paper presents result of harmonics measurement and analysis of harmonics characteristics in terms of loading, speed and operation mode.

• 한국초전도ㆍ저온공학회논문지
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• 제4권2호
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• pp.11-15
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• 2002

High speed probe for measurement of sin91e flux quantum circuits is comprised of coaxial cables and microstrip lines in order to carry high speed signals without loss. For the impedance matching between coaxial cable and microstrip line, we have determined the dimension of the microstrip line with 50${\Omega}$ impedance by simulation and then have investigated the effect of line width and cross-sectional shape of signal line, dielectric material, thickness of soldering lead at the coaxial-to-microstrip transition Point, and the an91c between dielectric material and end part of the signal line on the characteristics of signal transmission of the microstrip line. From the simulation, we have found that these all parameter's had influenced on the characteristic of signal transmission on the microstrip line and should be reflected in fabricating high speed probe, We have also determined the dimension of coplanar waveguide to fabricate testing sample for performance test of high speed probe.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.1404-1407
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• 2004

An electric railway system is composed of high-tech subsystems, among which main electric equipments such as transformers, converter and traction motors are critical components determining the performance of rolling stock. We developed a measurement system for on-line test and evaluation of performances of Korean High Speed Train. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A new method to measure temperature was applied to the measurement system. By using the system, measurement and evaluation for the performance of electric equipments in Korean High Speed Train was conducted during test running.

• 한국전기전자재료학회논문지
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• 제19권12호
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• pp.1128-1133
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• 2006

The most important thing to secure safety and reliability of railway vehicles is to verify performance characteristics of equipments, and related companies or research institutes had many efforts to verify performances and functions of equipments synthetically and efficiently. KHST(Korean High Speed Train) has been developed by KRRI (Korea Railroad Research Institute). An electric railway system is composed of high-tech subsystems, among which main electric equipment such as transformers and converter are critical components determining the performance of rolling stock. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A new method to measure temperature was applied to the ]measurement system. By using the system, fault diagnosis and performance evaluation of electric equipment in Korean High Speed Train was conducted during test running.

• 한국전기전자재료학회논문지
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• 제18권2호
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• pp.153-158
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• 2005

Recently, as the feasibility study shows that trans-Korea railway and trans-continental railway are advantageous, interest in high-speed railway system is increasing. Because railway vehicle is environment-friendly and safe compared with airplane and ship, its market-sharing increases gradually. KHST(Korean High Speed Train) has been developed by KRRI (Korea Railroad Research Institute) for last 6 years to satisfy the need. An electric railway system is composed of high-tech subsystems, among which main electric equipment such as transformers and converter are critical components determining the performance of rolling stock. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. A now method to measure temperature was applied to the measurement system. By using the system, fault diagnosis and performance evaluation of electric equipment in Korean High Speed Train was conducted during test running.

• 한국유체기계학회 논문집
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• 제16권3호
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• pp.18-25
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• 2013

Recently the requirement of long-term mobile energy source for mobile robot or small-sized unmanned vehicle is highly increased, and the micro turbine generator(MTG) which is known to have high energy and power density is under development. MTG is designed to have air foil bearing and high speed rotor of which operating speed is 400,000rpm. In the development stage of high speed rotor and bearing, stability analysis for the full operational speed range is essential and the dynamic coefficients such as stiffness and damping coefficients of bearing depending on the rotational speed are required for that. Although perturbation method is usually used to identify the dynamic coefficients, it's not easy to give the perturbation to the high speed rotating rotor. In this study, we present the dynamic coefficients measurement system for air foil bearing which consists of electromagnets, gap sensors, high speed motor and controller. This measurement system can exert the sine sweep force to the rotor-bearing, measure the displacement of rotor and get FRF(Frequency response function) of rotor-bearing. The least square estimation method is applied to identify the dynamic coefficients of bearing from the measured frequency response at the different rpm and the identified dynamic coefficients for the wide rotational speed range are presented.

• 한국정보통신학회논문지
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• 제8권1호
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• pp.28-33
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• 2004

풍속 및 바람 방향의 급격한 변화에 의한 기상위험 현상을 탐지하기 위해서는 공간상에서 풍속의 변화정도를 측정하는 것이 매우 중요하다. 이러한 기상현상들에서 전형적으로 내재된 높은 풍속의 측정을 위해서는 높은 PRF를 갖는 레이다를 필요로 한다. 그러나 공간상의 풍속의 변화정도를 예측하는데 있어서 이러한 큰 풍속의 절대적인 측정값이 꼭 필요한 것은 아니다. 따라서 본 논문에서는 실제적인 측면에서 매우 유용한 낮은 PRF를 갖는 레이다를 이용하여 풍속의 공간 변화율을 얻는 방법을 제안하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1374-1378
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• 2005

Appropriate upward force is crucial for the pantograph on high speed train to collect current from the catenery system without separation. However, at high speed, large aerodynamic lifting force is generated by the contact plate and the arms of pantograph, which may cause wear of the contact wire. In this study, to confirm the interface performance of the pantograph on Korea High Speed Train, a method to measure the contact force of the pantograph was proposed and the related measurement system was developed. The forces acting on the pantograph were clarified and a procedure to calculate the aerodynamic lifting force was proposed. A special device was invented and applied to measure the lifting force. Measured contact forces were displayed by the developed system and evaluated according to the criteria. Countermeasures were also taken to reduce the contact force based on the results.