• 한국정밀공학회지
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• 제30권10호
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• pp.1051-1059
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• 2013

In general, lateral ride comfort of railway vehicle is mainly influenced by a secondary suspension placed between the bogie and carbody. Higher operating speeds of train results in increased vibration of carbody, which has a negative impact related to the ride comfort. To solve this problem, researches to replace the conventional passive suspension with (semi)active technology in the secondary suspension of a railway vehicle have been carried out. The semi-active suspension using the magneto-rheological damper is relatively simpler system and has advantage in maintenance compared to the hydraulic type semi-active damper. This study was performed to reduce lateral vibration acceleration of carbody related to ride comfort of railway vehicles with a semi-active suspension system. The numerical analysis was conducted by replacing passive lateral damper with semi-active MR damper, and robust control with the MR damper was applied to the 1/5 scaled railway vehicle model.

• 한국소음진동공학회논문집
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• 제23권9호
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• pp.823-830
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• 2013

The purpose of this study is to develop a noise reduction device installed at the top of noise barrier for further decreasing of noise level of 400 km/h class high-speed railroad. For this, the frequency spectrum of 400 km/h class high-speed railroad was analyzed through the field noise test, and the tuning frequency was determined to design a noise reduction device. The noise reduction device was designed to have noise reduction performance of at least 3 dB(A) using the prediction method(2D BEM) and through the laboratory test with the prototype. Finally, the outdoor test showed that this device could decrease noise level of 400 km/h class high-speed railroad even more than 3 dB(A).

• 전기학회논문지
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• 제64권12호
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• pp.1789-1795
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• 2015

The pulley-type tensioning device subjected to a maximum tension of 34 kN has been developed for 400 km/h high-speed railway. The tensioning device is to maintain the tension variation within 3% of the normal value, irregardless of temperature changes. Field tests shows that the tensioning device had a variation of tension which was as small as 0.6% as temperatures changed from $-5{\sim}7^{\circ}C$. Along with the tensions, we measured its X and Y movements due to the temperature changes. Based on a combination of its X and Y movements, we proposed a new performance index with which we can see if the tensioning device has troubles in operation without tension measurements.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.479-487
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• 2004

The Korean railroad has developed as a foundation of nation's nucleus network. Nowadays Korea has entered into a new era because of the operation of KTX(Korea Train Express). As an introduction of KTX, the Korean railroad system has advanced Korean style high speed rail(HSR-350x), which is based on transfer and own technology. It is expected that the Korean rail road system has the leading design and production ability. Korea is planning to develop its own high speed railroad system until 2007. So the present task is to initiate a strategic export method for the development and value-added of Korean high speed railroad system. Furthermore this study proposes the administrative and technical policy for the basic technical research and creativeness predominance.

• 한국정밀공학회지
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• 제34권3호
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• pp.205-210
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• 2017

Critical speed analysis was conducted for a active steering bogie prototype, developed to improve the curving performance of railway vehicles. The critical speed for the design concept was about 169.2k m/h. To validate the analysis result, we performed a critical speed test for the prototype bogie using a roller-rig tester. The test results showed that the critical speed for the prototype bogie was about 165 km/h. From the analysis and test results, The critical speed for the prototype bogie was determined to be 165 km/h. Considering the maximum operating speed of the test vehicle is 100 km/h, the prototype bogie is considered stable.

• 한국철도학회논문집
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• 제16권1호
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• pp.14-19
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• 2013

고속철도차량의 실내소음은 승객에서 불쾌감, 피로감 및 스트레스를 유발하는 요인으로 이에 대한 지속적인 연구가 필요하다. 특히, 고속철도 차량이 개활지와 터널 등 다양한 주행환경에서 운행되고 있는 우리나라 현실에서는 이러한 환경에서의 실내소음 변화에 대한 구체적인 연구가 필요하다. 따라서, 본 연구에서는 현재 우리나라에 운영되고 있는 고속철도 차량에 대한 실내 소음의 특성을 분석하는 연구를 수행하였다. KTX와 KTX-산천 차량의 실내에 마이크로폰을 설치하여 주행 시 발생하는 실내소음을 분석하였으며, 축상, 대차 및 차체 가속도 센서를 설치하여 구조기인의 원인이 되는 진동을 검토하였다. 본 연구를 통해서 고속철도 차량의 속도에 따른 실내소음의 특성이 도출되었으며, 주행 환경이 실내소음에 미치는 영향을 개활지와 터널주행 시 발생하는 실내소음의 차이를 통해서 검토하였다. 또한, 차체진동과 실내소음에 대한 전달함수분석을 통해서 차체진동이 실내소음에 미치는 영향을 검토하였다.

• 전기학회논문지
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• 제64권8호
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• pp.1256-1261
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• 2015

Along with the increase of railway catenary system operation speed to 400 km/h, there have been growing demands for good quality current collection systems that satisfy quality standards as well as criteria for safe working. Retaining uniform elasticity tension of contact wires is essential in maintaining high quality contact between pantograph and OCL (Overhead Contact Line) of current collection systems in high speed railways. Therefore, the tension of contact wire must be kept within tight tolerance limits in both working conditions and adverse weather conditions of catenary system. In accordance with these conditions, this paper presents a real time monitoring system for the tensioning device of the newly installed catenary system on the special route of Honam high speed line for 400 km/h operation. For the verification of the true value of tension of contact wires, we have developed ring-type tensioning sensors which were installed on supporting points of mast which compose the catenary system. According to the field test performed on the Honam high speed line catenary system, variation of tension was measured accurately in real-time.

• Journal of Electrical Engineering and Technology
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• 제7권2호
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• pp.200-206
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• 2012

In order to develop a deep-underground great train express (GTX) in South Korea, the specifications decision and development of a traction control system (including an inverter and a traction motor), which considers a variety of route conditions, must be advanced. In this study, we examined the running resistance properties of a high-speed traction system based on a variety of tunnel types and vehicle organization methods. Then, we studied the power requirements necessary for the traction motor to maintain balanced speed in the high-speed traction system. From this, we determined the design criteria for the development of a high-speed traction system for use in the deep-underground GTX. Finally, we designed a linear induction motor (LIM) for a propulsion system, and we used the finite element method (FEM) to analyze its performance as it travelled through deep-underground tunnels.

• 한국정밀공학회지
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• 제30권7호
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• pp.667-672
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• 2013

This paper presents the development of a condition monitoring system that monitors the operating conditions of a reduction unit, such as the bearing temperature, gearbox vibration, and gear oil deterioration, and notifies the operator of potential problems or abnormal conditions. A series of field tests on high-speed rail and conventional lines was performed to identify the characteristics of temperature rise and vibration levels on the reduction unit during operation. The monitoring system was designed based on the proper sensor selection, measurement method, and signal analysis to optimize the interface with the operating system of high-speed trains. Application of this monitoring system to high-speed trains will play an important role in their proper maintenance and safe operation.

• 전기학회논문지
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• 제62권9호
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• pp.1343-1347
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• 2013

This paper presents an analysis methods for current collection quality in catenary system by means of video image based monitoring system. Arcing is the sparking at the interface point between pantograph and contact wire when the electric trains have traction current values at speed. Percentage of arcing at maximum line speed is measurable parameters for compliance with the requirements on dynamic behaviour of the interface between pantograph and contact wire in accordance with requirement of IEC and EN standards. The arc detector and video is installed on a train aim at the trailing contact strip according to the travel direction. The arc detector presented and measured verity of value such as the duration and power density of each arc and the video image is measured a image when the arc is occurred in pantograph. In this paper we analysis of video image in accordance with power density of arcing from arc detector and compared with video image and power density of arcing so as to produce quality of arcing from image.