• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.281-285
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• 2002

A new method of dynamic contact force measurement between a pantograph and a contact wire is proposed in this paper The method does not require design modification of an original pantograph in order to install sensors such as load cells. Contact forces can be expressed as the sum of vertical shear forces at the support points and inertial forces. Using specially-designed strain gage rosettes. vertical shear forces at the supported points can be measured without noise mixing and thermal effects. In order to obtain contact forces from shear forces, 3 inertial force compansation methods are proposed and compared in this paper. By validation process, the new proposed measurement method is verified to be applicable to the on-line current collection test.

• Journal of the Korean Society for Railway
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• v.4 no.2
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• pp.62-70
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• 2001

Pure copper, Cu-1.1wt%Cd and ACSR(Aluminum Conductor Steel Reinforced) have been used as catenary materials of the electric railway system. Since these materials may be exposed to the corrosive environments like polluted air, acid rain and sea water, it is important to investigate the corrosion rates in various corrosive environments. The aqueous corrosion characteristics of catenary materials in aerated acid, neutral and alkali solutions were studied by using immersion corrosion tests, electrochemical measurements and analytical techniques. In order to examine corrosion characteristics according to the dissolved oxygen content, pH, chloride ion concentration ion, and the addition of Cd to Cu, a series of tests such as potentiodynamic polarization, a.c impedance spectroscopy and galvanic corrosion tests were carried out with these materials. Results showed that the addition of Cd to Cu and chloride ion in the solution have an adverse effects on the resistance to corrosion. Additionally, Galvanic currents between Al and steel wires of ACSR were confirmed by using ZRA(zero resistance ammeter) method.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.9
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• pp.493-499
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• 2003

This paper presents exact Autotransformers(ATs)-fed AC electric Railroad system modeling using constant current mode for locomotives. An AC electric railroad system is rapidly changing single-phase load, and at a feeding substation, 3-phase electric power is transferred to paired directional single-phase electric power. As the train moves along a section of line between two adjacent ATs. The proposed AC electric railroad system modeling method considers the line self-impedances and mutual-impedances. The constant current mode model objectives are to calculate the catenary and rail voltages with the loop equation. When there are more than one train in the AC electric railroad system, the principle of superposition applies and the only difference between the system analyses for one train. Filially, this paper shows the general equation of an AC electric railroad system, and that equation has no relation with trains number, trains position, and feeding distance.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.223-224
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• 2015

도시철도에서 사용하는 전력공급 장치는 대부분 다이오드를 이용하여 전차선(DC)에 공급하고 있으며, 다이오드 특성상 단방향 전력공급이 가능하기 때문에 전동차의 회생제동으로 발생하는 회생 전력을 재사용 할 수 없는 단점을 가지고 있다. 따라서 본 논문에서는 전동차에서 발생하는 회생전력을 교류 모선으로 환원시켜주기 위하여 사이리스터를 이용한 양방향 더블컨버터를 제안한다. 더블컨버터의 제어 목적은 전차선의 부하에 따라 전압을 일정하게 유지시키면서 부하 조건에 따라 안정적인 모드 전환을 하는 것이다. 이를 위하여 더블컨버터의 병렬로 운전을 통하여 순차적인 모드 전환을 위한 알고리즘을 더블컨버터 시뮬레이션을 적용하여 검증하였다.

• 전기의세계
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• v.23 no.3
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• pp.21-25
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• 1974

본고에서는 다음의 내용을 다루었다. 1. 지하철의 건설목적 2. 구조물의 개요 3. 궤도 4. 송전 및 변압설비개요 5. 전력지령도 6. 전차선로 7. 신호보안설비 8. 통신설비

• Electrical & Electronic Materials
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• v.26 no.7
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• pp.28-34
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• 2013

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.9 no.2
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• pp.79-86
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• 2003

• Journal of the Korean Society for Railway
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• v.17 no.3
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• pp.157-164
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• 2014

The contact force between the pantograph and the catenary is a key factor determining the current collection quality, as they can ensure stable electrical power to the train. In this study, we analyzed the dynamic contact force for HEMU-430X depending on the train speed. It was confirmed through the results that the standard deviation of the contact force increases with an increase in the train speed. It was also verified that the span of the catenary system is a very important factor with regard to the contact force when analyzed with frequency analysis. To secure stable power in speed that exceeds 400km/h, the statistical variation of the contact force should be minimized. To realize this, the catenary tension was increased and the mass of the pan-head was decreased. The ensuing effects were then quantitatively analyzed in terms of the contact force. In addition, the differences in the contact force between a tunnel and an open field were analyzed based on a frequency analysis.

• Journal of the Korean Society for Precision Engineering
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• v.29 no.12
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• pp.1346-1350
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• 2012

Contact wire is one of the most important components supplying electricity to railroad cars. At the beginning of the research on contact wire, wear problem caused by friction between contact wire and pantograph was considered even more important issue for the failure of contact wire. However, since several fatigue fractures were reported from Shinkansen in Japan, fatigue fracture has become another important issue for the failure of contact wire. Despite of its importance, standard of the fatigue test of contact wire has not been established yet. Thus, fatigue characteristics of contact wire is very difficult issue to evaluate quantitatively. Hence, in this study, test method simulating operating conditions of contact wire by Minsung Kang and etc. is used to evaluate the fatigue characteristics of copper alloy contact wire. Also, test results is compared with the result of Minsung Kang's research on pure copper contact wire.

• Journal of the Korean Society for Railway
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• v.18 no.5
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• pp.410-418
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• 2015

A slider of the pantograph undergoes uneven and abnormal wear due to sliding contact with the catenary. In the case of rain, the loss of lubricant increases the frictional resistance for the reciprocating motion between the catenary and the slider, accelerating local wear. The slider in the winter should have good wear resistance, which can be achieved through alloy design. Uneven and abnormal wear were not observed in the results of a driving test using a wear resistant slider. It was found that the increased density of the slider enhanced the corrosive effects of Fe-Ti, preventing the occurrence of abnormal wear by maintaining the wear and arc resistance in the rainy season. Also, mechanical and electrical wear did not affect the composition of the slider, and this improved the wear resistance. Inaddition, the slider was applied to an entire train and was tested during driving; ananalysis of the correlation of the catenary was performed, including during the rainy season and the winter season.