• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.2
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• pp.117-126
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• 1999

The environmental impact of the KEPCO 765-kV transmission line was studied using a full scale test line in order to develop the design technology. Therefore this paper describes an environmental design summary of the audible noise, hum noise, wind noise, radio interference, TV interference and electric field measurement from the KEPRI 765-kV double circuit transmission test line with a bundle of $6-480mm^2$ conductors per phase. The analysis of the test results shows that 6-Rail and 6-Cardinal conductors bundle satisfy the audible noise criterion & TV interference under the stable rainy weather condition and the radio interference level under the fair weather. And the other items are also agreed with the design level criterion for KEPCO 765-kV transmission line.

• Journal of Mechanical Science and Technology
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• v.14 no.8
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• pp.867-878
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• 2000

In order to study unsteady aerodynamic loads on high speed trains passing by each other 350km/h, three-dimensional flow fields around trains during the crossing event are numerically simulated using three-dimensional Euler equations. Roe's FDS with MUSCL interpolation is employed to simulate wave phenomena. An efficient moving grid system based on domain decomposition techniques is developed to analyze the unsteady flow field induced by the restricted motion of a train on a rail. Numerical simulations of the trains passing by on the double-track are carried out to study the effect of the train nose-shape, length and the existence of a tunnel on the crossing event. Unsteady aerodynamic loads-a side force and a drag force-acting on the train during the crossing are numerically predicted and analyzed. The side force mainly depends on the nose-shape, and the drag force depends on tunnel existence. Also. a push-pull (i.e.impluse force) force successively acts on each car and acts in different directions between the neighborhood cars. The maximum change of the impulsive force reaches about 3 tons. These aerodynamic force data are absolutely necessary to evaluate the stability of high speed multi-car trains. The results also indicate the effectiveness of the present numerical method for simulating the unsteady flow fields induced by bodies in relative motion.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1370-1376
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• 2015

Generally, an autotransformer(AT) feeding system consists of double tracks, up and down, with the trolley wire and feeder wire of the up and down tracks connected in the sectioning post(SP). Consequently, load current or fault current flows on two tracks based on catenary impedance characteristics, making it difficult to estimate catenary impedance accurately. This paper presents a technique for the estimation of catenary impedance using boosting current compensation based on the current division characteristics of an AT feeding system to improve the operation performance of impedance relay. To verify the technique, we model an AT feeding system through a power analysis program (PSCAD/EMTDC) and simulate various operation and fault conditions. Through the simulation, we confirmed that the proposed technique has estimated catenary impedance with a similar degree of accuracy to the actual catenary impedance

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.599-604
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• 2000

In order to study unsteady aerodynamic loads on high speed trains passing by each other at the speed of 350km/h, three-dimensional flow fields around trains during the crossing event are numerically simulated using the three-dimensional Euler equations. The Roe's FDS with MUSCL interpolation is employed to simulate wave phenomena properly. An efficient moving grid system based on domain decomposition techniques is developed to analyze the unsteady flow field induced by the restricted motion of a train on a rail. The numerical simulations of the trains passing by on the double-track are carried out to study the effect of the train nose-shape, the train length and the existence of tunnel when the crossing event occur. Unsteady aerodynamic loads side force and drag force-acting on the train during the crossing are numerically predicted and anlayzed. It is found that the strength of the side force mainly depends on the nose-shape, and that of drag force on tunnel existence. And it is observed that the push-pull like impulsive force successively acts on each car and acts in different directions between the neighborhood cars. The maximum change of the impulsive force reaches about 3 tons. These aerodynamic force data are absolutely necessary for the evaluation of the stability of the high speed multi-car train. The results also indicate the effectiveness of the present numerical method for the simulation of unsteady flow field induced by the bodies in the relative motion.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.54-62
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• 2014

This study deals with the design and characteristics analysis on a linear synchronous motor (LSM) with a long stator and phase concentrated winding (PCW) to apply for a propulsion system such as a roller coaster for leisure facilities. First of all, the required propulsion force of LSM is computed and its design with double sided permanent magnets (PMs) and a phase concentrated winding is processed. The phase concentrated winding is composed of a module with each A, B, and C phase unlike an conventional concentrated winding (CW). It has an advantage of the installation and manufacture, compared to the conventional concentrated winding in the propulsion system for leisure facilities that have a long acceleration area and stator configuration placed on rail continuously. Thus, the design for the propulsion system and characteristics comparison between the phase concentrated winding and concentrated winding are carried out in this paper. Also, the analysis on dynamic characteristics is conducted to confirm the performance at operation.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.2
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• pp.57-63
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• 2003

A new method using a transfer function was proposed in the previous paper for analyzing motion errors of hydrostatic tables. The calculated motion errors by the new method, named as the transfer (unction method (TFM), were compared with the results by the conventional multi pad method, and the validity of the proposed method was theoretically verified. In this paper, the relationship between rail form error and motion errors of a hydrostatic table is examined theoretically in order to comprehand so-called 'the averaging effect of an oil film', and the characteristics of the motion errors in a hydrostatic table is tested. The tested hydrostatic table has three single-side pads in the vertical direction and three pairs of double-sides pads in the horizontal direction. The motion errors are tested for three rails which have different form errors. The experimental results are compared with the theoretical results calculated by the TFM, and both results show good agreement. From the results, it is shown that the TFM is very effective to analyze the motion errors of hydrostatic tables.

• Wind and Structures
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• v.28 no.4
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• pp.203-213
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• 2019

The topography and geomorphology are complex and changeable in western China, so the railway transition section is common. To investigate the aerodynamic effect of the subgrade-tunnel transition section, including a cutting-tunnel transition section, an embankment-tunnel transition section and two typical scenarios for rail infrastructures, is selected as research objects. In this paper, models of standard cutting, embankment and CRH2 high-speed train with the scale of 1:20 were established in wind tunnel tests. The wind speed profiles above the railway and the aerodynamic forces of the vehicles at different positions along the railway were measured by using Cobra probe and dynamometric balance respectively. The test results show: The influence range of cutting-tunnel transition section is larger than that of the embankment-tunnel transition section, and the maximum impact height exceeds 320mm (corresponding to 6.4m in full scale). The wind speed profile at the railway junction is greatly affected by the tunnel. Under the condition of the double track, the side force coefficient on the leeward side is negative. For embankment-tunnel transition section, the lift force coefficient of the vehicle is positive which is unsafe for operation when the vehicle is at the railway line junction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1279-1287
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• 2014

The Korean government establishes a strategy to develop the Busan New Port as a world ranking two transit-oriented port. This paper aims at presenting an efficient inter-terminal transport (ITT) system in the Busan New Port as a method of achieving the government strategy. First, it presents results of long term forecast for the inter-terminal transportation volume in the port. Second, it proposes two systems to treat ITT in the port; Double stack Multiple Trailer System (DMTS) and Rail-based transportation system. The implementation methods in the port are introduced in detail for the both systems, and the required number of the systems and costs are calculated for implementation of both the systems. B/C for DMTS is analyzed to 3.7, moreover unit-fare per [$ton{\cdot}km$] can is lowered to 67% against current fare. DMTS is shown to highly potential for efficient ITT in the port.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1517-1519
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• 1994

This paper describes electrical environmental study of a 765kV double circuit test line. Corona performance on several candidate conductor bundles has been investigated in the corona cage (single phase simulation facility) since 1984. We have known that six RAIL conductor bundle is the most suitable for the 765kV transmission Line, [3] To investigate electrical environmental impact of the future commerciale line, we build a full sacle 765kV test line in 1993. The test results of Audible Noise, Radio Interference, TV Interference from August, 1993 to Jan. 1994 were measured as $48.7[dBA](L_{50})$. $57.4[dB{\mu}V/m]$(Fair weather, $L_{50})$. $14.5[dB${\mu}$V/m]$(Fair weather, $L_{50}$). We have found that the Audible Noise data were very close to the predicted(48.5 [dBA]) by BPA Corona and Field Effects Computer program, however, the RI and TVI data were much higher than predicted(42 [dBmV/m], $7.9[dB{\mu}V/m)$ by the BPA program. We have investigating the reason of the difference. In the constructing of full scale test line, we developed the tubular tower, 765kV test transformer and hardwares of 765kV transmission line insulator strings. Also we will investigate the effects of plants under the 765kV test Line.

• Korean Business Review
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• v.21 no.2
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• pp.137-170
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• 2008

This study is presenting the logistics strategy in the international logistics markets which makes competition and corporation among north-east Asian countries to establishing the multi-pass Eurasian railroads. The countries located in north-east area of Eurasia like China, Japan, Russia and Korea are paying higher costs and disutility to the transportations and communications due to repeated conflicts and confrontations causes from the politic problems. They are being used surface transportation for most of all logistics between Europe and Asia except special merchandises because of characteristic of cargo to be air, the Silk Road remains vestige only which was main logistic passage to this area since BC. So far the Trans-Siberian Railway is being used by Russia mostly as north of Eurasian transport because of difficulties of service. The Trans-China Railway built in 1992 is not accomplishing as a international logistic passages. It is expected to take a long lead time because of characteristic of resource development and poor logistic infrastructure to the countries like Uzbekistan, double landlocked country, Mongolia and Azerbaijan, the countries do not be adjacent to the sea, even they have great economic jump-up plans through the development of their own resources. The Shanghai Cooperation Organization(SCO) start to sail officially in 2001 is constructed with China, Russia, Tadzhikistan, Kyrgyzstan, Kazakhstan and Uzbekistan as regular members of 6 countries and Mongolia, India, Pakistan, Afghanistan and Iran as observers 5 countries. It is started as a military alliance to protect terror, but now, it is expended to cooperate with the traffic, transportation, trade and share of energies. The Russia is doing their best to activate TSR as a government target to developnorth area equivalently, and economic develop of far-east Siberia. And also it is agreed provisionally to improve and repair of rail road between Nahjin and Hassan to connect TSR and TKR( Trans-Korea Railroad) by Russia, North Korea and South Korea with Russian's aggressive efforts. The development plan of this area is over lapped with GTI(Greater Tumen Initiative) promoted by UNDP, and is a cooperated project by 5 countries of South Korea, Mongolia, China, Russia and North Korea, subject to review the appropriation of energy, tour, environment, rail road connection between Mongolia and China and establishing a ferry route to north-east Asia. It is Japanese situation to pay attention to Russia and China even they have been supplying large-scope of infrastructure in Mongol area without any charges, target to get East Asia Main Rail Road to connect Mongolia and Zalubino of Russia. In case of the program for the Denuclearization of North Korea is not creeping, it will be accelerated to connect the TKR and TSR, TKR and TCR by somehow attending United States, including developing program promoted by UN ESCAP. As the result, Korean peninsular will continue the central role of competition and cooperation as in the past, now and future of north-east Asia, as of geographical-economics and geographical-politics whether it is requested or not wanted by neighbor countries.