• Journal of Energy Engineering
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• v.5 no.2
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• pp.138-145
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• 1996

The particulate collection at high temperature and high pressure (HTHP) is important on the advanced coal power generation system not only to improve the thermal efficiency of the system, but also to prevent the gas turbine from erosion and to meet the emission limits of the effluent gas. The specifications for particulate collection in those systems such as Integrated Coal Gasification Combined Cycle (IGCC) and Pressurized Fluidized Bed Combustion (PFBC) require the absolutely high collection efficiency and reliability. Advanced cyclone, granular bed filter, electrostatic precipitator, and ceramic filter have been developed for particulate collection on the advanced coal power generation system. However, rigid ceramic filters and granular bed filter among them show the best potential. The current technology of these collectors was evaluated in this paper. The experienced problems of these systems on performance, materials, and mechanical design were investigated. Ceramic candle filters has the best potential for IGCC at this moment because it has nearly the highest efficiency comparing with other filtering systems and has accumulated many reliable design data resulted from many field experiences.

• Journal of the Korean Society for Railway
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• v.15 no.5
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• pp.429-435
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• 2012

The HEMU-430X is a world-class railway vehicle which aimed the maximum speed of 430km/h and the operation speed of 370km/h. To maintain high-speed operation condition over 300km/h, various requirements for satisfy exist. However, one of the most important things is a reliable supply of electricity. Especially, the dynamic interaction between the pantograph and overhead contact line at high-speed is a significant matter to pre-evaluate. In this paper, using the dynamic interaction analysis program, current collection performance of the HEMU-430X was investigated. Firstly, based on the international standard, performance of the original specifications was evaluated. In addition, through study on changes in tension and span length, improvement of the performance was considered.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.6
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• pp.855-859
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• 2014

Quality criteria for interaction between a pantograph and overhead contact wire is a most important requirement to assess of the performance for the current collection system. Interaction performance between pantograph and catenary system is subject to approval by the infrastructure manager when a new design and contraction of overhead contact line and pantograph are installed. Among the various performance, percentage of arcing at maximum line speed is a simple test method compared with contact force of pantograph due to direct sensing of pantagraph, calibrations, installations of train, and etc. On the other hand, percentage of arcing is need to reliable arcing detector and general requirements with accordance with EN 50317. In this paper, percentage of arcing are investigated on the function of duration of arc and proposed which is satiable of percentage of arcing. As a results, we proposed which duration of arcs are unsuitable from infrastructures point of view as performance testing for quality of current collection.

• Journal of the Korean Society for information Management
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• v.23 no.4 s.62
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• pp.17-39
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• 2006

Building institutional repositories is known as one of powerful methods for realizing the open access movement. The Korean Education and Research Information Service(KERIS) proposed to organize institutional repositories into a consortium, called 'dCollection (Digital Collection),' composed of 62 universities since 2003. The purpose of this study is to investigate the current state of 40 member universities of dCollection using the evaluation model including 4 categories and 39 indicators , and, based on the survey outcomes, to pinpoint the procedural or performance weak points of the dCollection systems in order to find its customized solutions focusing on the improvement of use and self-archiving rates.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.227-235
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• 2007

The railway catenary is softer in the middle of a span than at the end. This stiffness variation induce the vertical motion of a moving pantograph, which results in the large variation of contact forces. To reduce the vertical motion of a pantograph, we can introduce a pre-sag of the contact wire. The pre-sag changes merely equilibrium position of the contact wire. Because the pantograph must follow the sag added to the motion of the contact wire, the sag gives downward forces to the pantograph. If the pre-sag is proper, the variation of the vertical motion of the pantograph is reduced. However, excessive sag worses the current collection performance because the pantograph receives too large downward forces by the contact wire. The objective of the paper is to establish the theoretical basis to understand how the pre-sag affect the contact force variation and to propose the proper sag for the railway catenary for the train speed up to 200 km/h.

• Journal of the Korean Society for Railway
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• v.8 no.1
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• pp.51-56
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• 2005

A dynamic simulation program of a catenary-pantograph system including tunnel section and transient section is developed in this study. The simulation program can accommodate for the pantograph of two panheads and three d.o.f model. Using the developed program, the dynamic characteristics with a SCHUNK'S WBL 85-PANTOGRAPH are analyzed at the conventional TAEBAEK line and its tunnel section when the catenary system is supported by a tunnel bracket. The simulation results show that the variation of contact force md uplift displacement is allowable in general section and the entrance and exit of a tunnel, but the uplift displacement and the separation ratio within tunnel section is difficult to allow.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.134-139
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• 2001

Pantographes should follow periodical motions with hanger and span passing frequencies during operation in order to have good dynamic follow-up characteristics. According to the dynamic simulations of a pantograph together with catenary systems, the best current collection performance of a pantograph is obtained when receptance peak frequencies are matched with hanger and span passing frequencies. Based on this principle, design variables of G7 pantograph are selected. However, because a high-speed train may run in the wide range of speeds and induce aero-acoustic noises, the design variables are adjusted to escape from these problems with a little sacrifice of current collection performance.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.665-674
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• 2006

This paper presents the optimal design of a high-speed (200[km/h]) Linear Synchronous Motor which will be used as a propulsion system of a dynamic tester for catenary-current collection used in railways. Motor performance, especially detent force minimization on various design schemes has been investigated in detail by using FEM (Finite Element Method). Simulation-based DOE (Design of Experiments) method is also applied in order to reduce the large number of analysis according to each design variable and consider the effect among variables. The optimal design in all aspects is proposed by an optimization algorithm using a regression equation derived from the simulation-based DOE and the performance is verified by FEM.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.201-206
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• 2009

In the testing stage of HEMU-400X(next Korean high speed train) developing project, maximum speed(400km/h) tests will be conducted. On present and near future conditions of the overhead contact lines, 400km/h is over the design speed criteria. The predictions of current collection performance including the percentage loss of contact(arcs level) parameter through dynamic interaction simulation of HEMU-400X maximum speed test run are described in this paper. Various simulations are conducted at the condition of two different contact wire tensions to draw the proper contact wire increasing values in the 400km/h test line under the available contact wire tension supporting condition of that line.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.1
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• pp.43-48
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• 2012

This paper presents the characterization of micro-tubular SOFCs using three different anode current collecting methods of inlet current collection (IC), both current collection (BC) and total current collection (TC). The maximum power densities of SOFCs at $750^{\circ}C$ using IC, BC and TC were 56 mW/$cm^2$ (0.43 V, 0.13 A/$cm^2$), 236 mW/$cm^2$ (0.43 V, 0.55 A/$cm^2$) and 261 mW/$cm^2$ (0.43 V, 0.61 A/$cm^2$) respectively. It was confirmed by impedance spectroscopy that both the polarization resistance and the ohmic resistance were dramatically increased at SOFC with IC.