• Proceedings of the KSR Conference
• /
• 2000.11a
• /
• pp.535-542
• /
• 2000

Pure copper, Cu-1.1wt%Cd and ACSR(Aluminum Conductor Steel Reinforced) have been used as Catenary Materials in Electric Railway System. Since these materials may have chance to be exposed to the corrosive environments like polluted air, acid rain and sea water, it is important not only to investigate the corrosion characteristics but also to measure corrosion rates in various corrosive environments. 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 in these materials. Results showed that the addition of Cd to Cu and chloride ion in the solution have an adverse effect on the resistance to corrosion. Additionally, Galvanic currents between Al and steel wires of ACSR were confirmed by using ZRA(zero resistance ammeter) method.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.204-212
• /
• 2010

Currents which are generated at both ends of drive motor by operating brake pedal when subway train is driving, will generate the reviltalization actual effect if they are not used immediately. So there exist rolling stock established Dynamic braking annex for the purpose of stable brake performance in case there are no retrogress train around or no stable wiring voltage.Therefore 55% of entered energy are consumed in subway train. 45% are used in down gradient section or for regeneration energy and among them 25% are used for another train's retrogression through the wiring. So to reduce reviltalization method keeping the existing system, substation's service voltage should be declined about 5%. And then it will ease off excessive wiring voltage rise. And there need energy reduction by flexible service voltage adjustment and study for energy consumption efficiency in the subway.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.16 no.6
• /
• pp.87-94
• /
• 2002

As a section insulator dividing the electric railroad catenaries with different phases, the AC/DC section insulator which divides AC and DC railroad catenary have the complex structure, and suffer irregular abrasion on the surface or insulator rods when it is installed at the underground railroad. This paper intended as an investigation of the irregular abrasion of section insulators, provides the field measurements of abrasion level along insulator length and the abrasion patterns. The height variation of insulator parts and the balding length of insulators against pantograph's contact force are analysed experimentally, and the irregular abrasion mechanism is clarified with the help of theoretical analysis on the interaction between pantographs and section insulators. On the basis of experimental and theoretical analysis, the countermeasures to reduce the irregular abrasion are provided too.

• Journal of Forest and Environmental Science
• /
• v.9 no.1
• /
• pp.57-66
• /
• 1993

The purpose of this study is to offer detailed topographic information for substantially selecting the yarding machine for mechanized yarding operations, classifying the forest site by cluster analysis and principal component analysis, and investigating simultaneously the variables which give much influence on the classification of forest site in forestry build-up region (21, 477ha) of Chunchon Gun, Kwangweon Do. Ten topographic variables were used for the analysis. The results of study were as follows : 1) Gosung region (2, 252ha) was classified into hilly terrain (57%) and steep terrain (43%) and required the tractor prehauling system for the former one and the medium skyline system for latter one, respectively. 2) 65% of Gajung region (2,306ha) and 67% of Kwangpan region (2, 627ha) were classified into steep terrain fitted for the medium skyline system and the portion of both region showed the hilly terrain for the tractor prehauling system. 3) Jiam region (4, 591ha), consisted only of steep terrain, required the medium skyline system. 4) Gunja region (3, 400ha), Sudong region (3, 984ha) and Sinpo region (2, 340ha) were classified into steep terrain, requiring the medium skyline system, with 85%, 75%, and 75%, respectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2012.04a
• /
• pp.711-712
• /
• 2012

• 전기의세계
• /
• v.24 no.5
• /
• pp.441-441
• /
• 1975

Cape Code해협과 New England의 345KV 간선을 Boston 서남쪽으로 약 15 Miles 떨어진 지점에 연결되어 있는 Cannal-Walpole 송전선에는 내층에 A1선을 사용하고 외층에 A1합금선을 입힌 새로운 형태의 ACAR가 채용되었다. 이 전선은 종래의 ACAR연선과는 구성이 다른 것으로서 37개의 경A1선을 내층에 두고 54개의 5005합금선을 외층에 두고 있는 2,335MCM(1,180mm$^{2}$)의 대형 송전선이며 현재 실제가선에 의한 현장시험이 행하여 지고 있다.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.529-533
• /
• 2005

A railway catenary system which supplies a train with electric power is an important system in determining the maximum speed of an electric train. However, a pantograph could be separated from a contact wire because of reciprocal action between a pantograph with constant upward force and a catenary system. The contact loss of a pantograph-catenary system is mainly affected by the dynamic characteristics of damping and wave propagation velocity of contact wire. For increasing speed of an electrical train, it is necessary to establish the techniques to identify the modal parameter of a catenary system through experiment. However, it is difficult to decouple each mode and to extract respect ive damping rat io since a catenary system has an extremely high modal density. For this reason, mode decoupling process to identify modal parameters is a principal technique in analyzing a catenary system. In this paper, the damping extract ion method for a catenary system using the continuous wavelet transform is discussed.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.1
• /
• pp.152-159
• /
• 2005

The dynamic properties between catenary and pantograph of high-speed train are very important factors to affect the stable electric power supply. So as to design the reliable current collection system, a multibody simulation model is needed. In this paper, the dynamic analysis method for a pantograph-catenary cable system of high-speed train is presented. The very deformable motion of a catenary cable is demonstrated using nonlinear continuous beam theory, which is based on an absolute nodal coordinate formulation, and the pantograph is modeled as a rigid multibody. The proposed method might be very efficient, because this method can present the nonlinear properties of a flexible catenary cable and set a various boundary conditions.

• Journal of the Korean Society for Railway
• /
• v.13 no.1
• /
• pp.16-22
• /
• 2010

Various programs for dynamic simulation of the railway vehicle have advantages and disadvantages. These programs have limitation that cannot express a large deformable body for an wire of the railway vehicle. In this study, a program for dynamic simulation of the railway vehicle is developed. And the rigid, flexible and large deformable body can be simulated using this program. Its reliability is verified by comparison with a commercial program. Also, a wire is considered as the large deformable body and a sliding joint which connects the rigid body to the large deformable body is included. Moreover, as the wheel-rail contact module is added, the dynamic simulation of the railway vehicle can be analyzed using the developed program.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.14 no.6
• /
• pp.481-487
• /
• 2009

This paper proposes a regulation method of DC line voltage for urban transit system fluctuated during the acceleration or deceleration by using supercapacitor. Supercapacitor is modelled electrically under the assumption of three different time constants of RC circuits with variable capacitances depending on the voltage. And its parameters are determined by the experimental measurements. The energy storage system using supercapacitors is installed based on this model, and the proposed model is tested through the simulations and experiments, and the controller for charging and discharging is designed. Finally, it is tested at Kyoungsan test site for the urban light rail road system and the energy saving effect is evaluated economically.