• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.192-192
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• 2010

DAPAS (Development of Advanced Power system by Applied Superconductivity technologies) program that the, superconductivity national program has been started one of the 21C frontier programs from 2001 in Korea. The 3rd phase of DAPAS program was started at April 2007, and the ultimate goal of HTS cable project is to develop 154kV, 1GVA class HTS cable. The structure of 154kV, 1GVA HTS cable is single core with cold dielectric insulation. The cable core consists of the former, conduction layer, electrical insulation layer, shielding layer. The cable cryostat consists of two corrugated seamless aluminum tubes as its high sealing reliability, the tubes separated through a spacer arrangement. Outdoor termination was developed by LS cable and cryogenic system by CVE for 154kV, 1GVA class HTS cable. The 154kV, 1GVA HTS cable will be installed and be tested in KEPCO Gochang Testing Center from June 2010.

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.21-27
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• 2015

The goal of this study is the size and distribution of the electromagnetic force generated by the current flowing through the second underground line of 154kV power transmission cables by using electromagnetic finite element analysis. So we interpret how mutually electromagnetic force has an effect on the comparable judgement of Trefoil, Duct and Flat, which shows in a numerical arrangement. 154kV OF 1200SQ Cable 1.281km not only is applicable to modeling for underground transmission cable but also examine the effect of line to line, phase to phase and size and direction of the electromagnetic force preparing for the occurrence of normal state and single-phase earth fault, which are arranged in trefoil, duct and flat formation between sections. As showing how the trajectory, and size distribution of the electromagnetic force translate as the arrangement of the cables when a steady-state current and a fault current flows on the underground cables, I hope that when Underground transmission is designed, this data will be useful information.

• Wind and Structures
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• v.30 no.6
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• pp.617-631
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• 2020

Wake-induced aerodynamics of yawed circular cylinders with smooth and grooved surfaces in a tandem arrangement was studied. This pair of cylinders represent sections of stay-cables with smooth surfaces and high-voltage power conductors with grooved surfaces that are vulnerable to flow-induced structural failure. The study provides some insight for a better understanding of wake-induced loads and galloping problem of bundled cables. All experiments in this study were conducted using a pair of stationary section models of circular cylinders in a wind tunnel subjected to uniform and smooth flow. The aerodynamic force coefficients and vortex-shedding frequency of the downstream model were extracted from the surface pressure distribution. For measurement, polished aluminum tubes were used as smooth cables; and hollow tubes with a helically grooved surface were used as power conductors. The aerodynamic properties of the downstream model were captured at wind speeds of about 6-23 m/s (Reynolds number of 5×10⁴ to 2.67×10⁵ for smooth cable and 2×10⁴ to 1.01×10⁵ for grooved cable) and yaw angles ranging from 0° to 45° while the upstream model was fixed at the various spacing between the two model cylinders. The results showed that the Strouhal number of yawed cable is less than the non-yawed case at a given Reynolds number, and its value is smaller than the Strouhal number of a single cable. Additionally, compared to the single smooth cable, it was observed that there was a reduction of drag coefficient of the downstream model, but no change in a drag coefficient of the downstream grooved case in the range of Reynolds number in this study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.210-218
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• 2019

Recently, cable-stayed bridges have been attempting to apply bold and experimental shapes for aesthetic and originality. In the case of bridges that have no similar cases, deep understanding and verification of analytical modeling is needed. S-shaped curved pedestrian cable-stayed bridge is always twisted because the cable is arranged on one side of the inverted triangular truss girder. In order to suppress the torsion, the Link-shoes are arranged at the left and right top members with reference to the Bearing placed at the mid-bottom member. The first research is related to the modeling method of Link-Shoe and Diaphram. In order to accurately reflect the transverse structural system and the torsional stiffness, it was necessary to model the Link-Shoe and the Diaphram directly rather than indirectly using the stiffness of the Bearing. The second study is related to the lateral arrangement of Bearing and Link-Shoes. Method 1 is to place in order of Link-shoe, Bearing, and Link-shoe from outside the curve radius. Method 2 is place to in order of Bearing, Bearing, and Link-shoe. In method 2, compared to method 1, the stress in the outer top member was larger and the stress in the inner one was decreased. It is analyzed that the stress adjustment is possible according to the lateral arrangement of Bearing and Link-Shoe.

• Journal of Korean Association for Spatial Structures
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• v.17 no.1
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• pp.31-40
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• 2017

The objective of this study is to analysis the mechanical characteristics and nonlinear behaviors on the geometric nonlinear behavior of a cable spoke wheel roof system for long span lightweight roof structures. The weight of a cable spoke wheel roof dramatically can reduce and the cable roof system can easily make the required rigidity and shape by the sag ratio and pretension forces. Determining the pretension and initial sag of cable roof system is essential in a design process and the shape of roof is changed by pretension. The nonlinear behavior of flexible cable system has greatly an affect on the sag and pretension. This paper will be carried out analyzing and comparing the tensile forces and deflection of a cable spoke wheel system for the large span retractable roof, and analyzed to deflections and tensile forces by the post height of center hub. The double arrangement of a spoke wheel system with reverse curvature works more effectively as a load bearing system, the pretension can easily increase the structural stiffness. The cable truss system can carry vertical load in up and downward direction, and act effectively as load bearing elements.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.2
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• pp.113-120
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• 2008

This study presents the ULMM(unstrained-length-modification method) to determine the cable tension consistent with target tension after arrangement of cable-members by controlling the unstrained length of cables. This method used to be shown to determine the exact unstrained length for cable-supported bridge with elastic catenary cable. The some verification examples show to determine the unstrained length that satisfies the target tension and to obtain the satisfactory result for cable-supported bridge. Accordingly this modification method of the unstrained length in this study is used to introduce the satisfactory target tension.

• Journal of international Conference on Electrical Machines and Systems
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• v.2 no.4
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• pp.413-420
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• 2013

This paper includes the results of the electromagnetic finite element analysis with regard to overheating problem of the power cable tray due to asymmetric magnetic flux density. This phenomenon was experienced in the utility power plant, Korea. The influences of the power cable arrangements and material of the tray were analyzed to find the best solutions using the eddy current-thermal coupled analysis.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.565-580
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• 2006

Set in constant increase and period current of lively technical development of railroad use and construction of cable stayed bridge railway bridge, one of bridge form of most suitable that think side police officer and the material enemy of bridge that use long rail, is increasing laying stress on the foreign countries. Main tower fixing department of this cable stayed bridge is consisted of main tower flange that support bearing plate, bay ring plate bearing plate, support end rib and diaphragm etc, as stress transmission mechanic that tensility of cable socket into normal force of main tower, and is used this time. These structural elements is very complex the structure and direction of load delivered from socket specially calbe particularly be different, and need FEM analysis that use Thick Shell element for suitable arrangement of mutual stress flowing grasping and absence that follow hereupon because all of the each support plate angle that suport this differ.

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.13-13
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• 2017

• Journal of Korean Association for Spatial Structures
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• v.17 no.2
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• pp.21-32
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• 2017

The objective of this study is to analysis the mechanical characteristics on the geometric nonlinear behavior of radial cable roof systems for long span retractable cable roof structures. The retractable roof is designed as a full control system to overcome extreme outdoor environments such as extreme hot or cold weather, strong wind or sunlight, and the cable roof greatly can reduce roof weight compared to other rigid structural system. A retractable cable roof system is a type of structures in which the part of entire roof can be opened and closed. The radial cable roof is an effective structural system for large span retractable roofs, the outer perimeter of the roof is a fixed membrane roof and the middle part is a roof that can be opened and closed. The double arrangement cables of a radial cable truss roof system with reverse curvature works more effectively as a load bearing cables, the cable system can carry vertical load in up and downward direction. In this paper, to analyze the mechanical characteristics of a radial cable roof system with central posts, the authors will investigate the tensile forces of bearing cables, stabilized cables, ring cables, and the deflection of roof according to the height of the post or hub that affects the sag ratio of cable truss. The tensile forces of the cables and the deflection of the roof are compared for the cases when the retractable roof is closed and opened.