• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.131-133
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• 2000

Single phase simulations were carried out in order to determine a solutive conductor to the aeolian noise which will be locally applied to 765 kV transmission lines Basic solutive conductors have already been proposed including conductors equipped with spiral rod. low noise conductor of a special shape and others. A low aeolian noise conductor, however, should have excellent corona characteristics in addition to aeolian noise reduction function. In this paper, we compared the performances of the audible noises and radio interferences of 6 candidate conductor bundles by using corona cage. We also developed two programs to need for evaluating environmental effects of each conductor bundle. Those are a program to calculate the conductor surface gradient of various special bundles and a conversion program of single phase data to the model of transmission line. The future determination on the final low aeolian noise conductor will be made through a long-term test to verify environmental impacts at the full-scale Kochang 765 kV test line.

• Proceedings of the KIEE Conference
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• 2001.05a
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• pp.254-258
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• 2001

In this paper, 3-dimensional charge simulation method was developed to analyze electric field distributions of special conductor bundles equipped with spiral rods for reducing aeolian noise. When we applied this method to 765 kV double circuit transmission line, we found calculation error of this method was within a reasonable boundary of 1%.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.359-361
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• 2001

In this paper, 3-dimensional charge simulation method was applied to analyze electric field distributions of special conductor bundles equipped with spiral rods for reducing aeolian noise in a corona cage. We found calculation error of this method was w a reasonable boundary of 0.5%.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.45 no.4
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• pp.612-615
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• 1996

Audible noise from corona discharge had been identified as one of the most important factors in the design of conductor configurations for high-voltage transmission lines. 500kV and above. Therefore this paper describes audible noise characteristics of 6 X 480mm conductor bundle in KEPRI 765kV Test Line and Corona Cage. Prediction formula for audible(corona) noise on a 765kV transmission Line was developed using this results.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.128-133
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• 2003

In this paper, we have proposed a method by using virtual simulation to calculate the behaviors of spacers to avoid conductor galloping with the hanging composite polymer spacer between conductors on different phases. We have considered with three types of modeling considerations for the analysis of galloping in power transmission lines, such as iced-single conductors without spacer, iced-single conductors with spacers, and iced-two bundle conductors with spacers. In simulation, the finite element method is used to calculate the structural response with geometric nonlinear behavior. The iced conductor is modeled by two beam-element faces with which it is connected. The ANSYS program is applied too. First, the calculation results show that the two beam-element model is very suitable to make a virtual simulation. Second, the amplitude of conductor galloping is reduced after hanged spacers. Third, when number of spacer is increased, the maximum magnitude of natural frequency of iced conductor will reduce. Final, the behaviors of spacers are verified in viewpoint of standard cases.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.197-200
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• 1989

The corona interference of extra high voltage (EHV) transmission lines has to be considered as an important design factor for establishing an electrical environmental countermeasure at a basic line design stage. This paper describes the conductor selection procedure through both corona performance test result in corona cage and its evaluation by the design criterion. It is known that three conductor configurations including $6{\times}810mm^2$ (spacing: 40 cm) are the suitable conductor bundle for the environmental preservation around both 2-circuits and 1-circuit T/L.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.3
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• pp.110-118
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• 2003

Spacer dampers maintain the constant gaps between each conductor in a bundle conductor-transmission line, and are installed at proper intervals to keep a line from all sorts of damages derived from the vibration energy caused by mechanical or electrical external factors. It is most important to embody a technology which considers difficulties of maintenance and repair, and has optimum elements in order to prevent accidents such as destruction by fire or the snapping of a wire by the effect of vibration phenomenon coming from transmission lint In the resent thesis, therefore, the analysis of vibratory characteristics of spacer damper is set up by analytical methods such as the analysis of conductor motion's governing equation, the equation of spacer damper's motion, spacer damper-fastened wire's motion in a span and the numerical analysis of finite difference method. Furthermore, the installation distance between spacer dampers was scrutinized by simulations of various vibration phenomena which change at any time as actual conditions do, and hereafter difference method. Furthermore, the installation distance between spacer dampers was scrutinized by simulations of various vibration phenomena which change at any time as actual conditions do, and hereafter we will be able to analyze all kinds of vibration phenomena coming from a boltless spacer damper with 6 bundle conductor for 765kV transmission line based on new analytical methods.

• Progress in Superconductivity and Cryogenics
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• v.14 no.1
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• pp.4-7
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• 2012

Coated conductors have been developed to increase piece length and critical current for electric power applications. Otherwise, Many efforts were carried out to reduce AC loss of coated conductor for AC applications. Twisting and cabling processes are effective to reduce AC loss but, these processes can not be applied for tape shaped coated conductor. It is inevitable to have thin rectangular shape because coated conductor is fabricated by thin film deposition process on metal substrate. In this study, round shape superconducting wire was first fabricated using coated conductors. First of all, Ag coated conductor was used. coated conductor was slitted to several wires with narrow width below 1mm. 12ea slitted wires were parallel stacked on top of another until making up the square cross-section. The bundle of coated conductors was heat treated to stick on each other by diffusion bonding and then copper plated to make round shape wire. Critical current of round wire was measured 185A at 77K, self field.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2003.06a
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• pp.262-267
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• 2003

At process of production according to development of accumulation degree of semi-conductor element, because functional mistake examination time required increases, is becoming big obstacle factor in cost-cutting. Studied pattern generator that generate pattern and address that is bundle enemy to process these controversial point effectively.

• Nuclear Engineering and Technology
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• v.55 no.12
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• pp.4597-4606
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• 2023

Thermal analysis of the CANDU spent fuel dry storage canister is very important to ensure the integrity of the spent fuel. The analyses have been conducted using a conservative approach, with a particular focus on the peak cladding temperature (PCT) of the fuel rods in the canister. In this study, we have performed a realistic thermal analysis using a computational fluid dynamics (CFD) code. The canister contains 9 fuel bundle baskets. A detailed analysis of even a single basket requires significant computational resources. To overcome this challenge, we replaced each basket with an equivalent heat conductor (EHC), of which effective thermal conductivity (ETC) is developed from the results of detailed CFD calculations of a fuel bundle basket. Then, we investigated the effects of some conservative models, ultimately aiming at a realistic analysis. The results revealed: (i) The influence of convective heat transfer in the basket cannot be ignored, but it's less significant than expected. (ii) Modeling of the lifting rod is crucial, as it plays a decisive role in axial heat transfer at the center of the canister and significantly reduces the PCT. (iii) Convection within the canister is very important, as it not only reduces the PCT but also shifts its location upwards.