• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.5
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• pp.480-485
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• 2006

A research was undertaken on the thermal properties and behavior of the conductors in a controlled chamber, which was designed to implement the outdoor air temperature, heat and wind conditions With ACSR $410mm^2$ overhead conductors, we measured the maximum temperature of the conductors and the temperature gradient from the core to the surface regions as a function of current, tension, wind velocity and outdoor air temperature. This test also provided a comparative analysis between the measured temperature values of conductors in the controlled chamber and the theoretical calculations of ANSI/IEEE at normal condition. There was not much influence of tension on the conductor temperature. However, the compactness of conductor wires increased with an increase in tension, which eventually increased the coefficient of effective thermal conductivity and, accordingly the conductor temperature was reduced more or less.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.523-524
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• 2007

Forest fire can give a serious damage to overhead conductors. Therefore, the definite understanding about aging behavior of burned conductor is very important in maintaining the transmission line safely. It is sure that the temperature of conductor itself will be affected by the distance apart from flame. From this point of a view, we monitored the conductor's temperature with distance from flame. As a result, the conductor's temperature decreased as the flame goes away from the conductor gradually. The temperature of conductor was reached up to 55~65% level of its atmospheric temperature. The detailed results will be presented in the text.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.3
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• pp.280-286
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• 2006

As a way to expand electric capacity in conductor with electric power demand, STACIR/AW (Super Thermal-resistant Aluminum-alloy Conductors Aluminum-clad Invar-Reinforced) conductor which has high electric current and heat resistance characteristics have been developed. STACIR/AW power line is mechanical composite wire composed of steel cores for dip control and aluminum conductors for sending electric current. Recently, to ensure stable operation and prediction of wire life span of STACIR/AW conductor, a heat property of STACIR/AW conductor have been investigated. In the present work, a change of essential property with long term-heat exposure of STACIR/AW conductor and its structure material, INVAR wire and Al conductor, have been investigated. INVAR/AW is approximately $3.2\;{\mu}m/m^{\circ}C$. thermal expansion coefficient of INVAR/AW wire increases with time of heat exposure. the thermal expansion coefficient of INVAR/AW is markedly influenced by heat and mechanical treatment. creep rate(0.242) of STACIR/AW $410\;mm^2$ conductor at room temperature is much higher than that(0.022) at $210\;^{\circ}C$ STACIR/AW $410\;mm^2$ conductor has minimum creep rate at operating temperature. To lower creep rate with increase temperature is more unique characteristics in STACIR/AW. It is expected that STACIR/AW turned its tension to INVAR/AW at the transition temperature. at room temperature, the tension apportionment of INVAR/AW in STACIR/AW is about $50\;\%$. but whole tension of STACIR/AW is placed on the INVAR/AW alone of core metal above transition temperature.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.3
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• pp.119-126
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• 2003

The size of low voltage level conductor cables can be installed with a long length just like a aviation field, shall be determined for considering the ampacity of cable and the drop of voltage for the power system. Therefore, The size of the conductor cables may be larger one for considering the tolerable voltage drop comparatively, although the allowable ampacity of the conductor cables may have a margin in comparison with the rated full load current In this case, the conductor cables' allowable ampacity will be very larger than the rated full load current and the generated heat of the conductor will be relatively downed. The conductor cables' alternating current resistance corrected with the maximum allowable temperature of the conductors, has been applied on the general formula for the calculating the voltage drop in determinating the size of low voltage level conductor cables, and the resistance is larger than the resistance corrected with the actual temperature of the conductor cables. This paper was studied for the purpose of the conductor resistance corrected with the actual temperature rise of the conductor and address the economic design formula so that this studies shall minimize the errors which can be occurred in comparison with the general formula and which can be applied in design work for determining the size of low voltage level conductor cables.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.5
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• pp.486-491
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• 2006

A research was undertaken on the thermal properties and behavior of the conductors in a controlled chamber, which was designed to implement the outdoor air temperature, heat and wind conditions. With ACSR $410mm^2$ overhead conductors, we measured the maximum temperature of the conductors and the temperature gradient from the core to the surface regions as a function of current, tension, wind velocity and outdoor air temperature. This test also provided a comparative analysis between the measured temperature values of conductors in the controlled chamber and the theoretical calculations of ANSI/IEEE at normal condition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.4
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• pp.366-371
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• 2009

The authors have published several technical reports on the deterioration of conductor due to forest fire in series so far. This is because even we have been experiencing hundreds of forest fires every year, no systematic research on conductor which is very vulnerable to fire have been fulfilled. This paper describes the sag-tension behavior of conductor under loading current normally when only partial area of a long conductor is exposed to fire. Temperatures of Overhead Conductor were different with measurement position. When the partial area of conductor was heated up to $500^{\circ}C$, 20 % of permanent tension loss was observed. This results in the increase of sag of 1.5 m when span is 300 m. The other results will be presented in the text.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.3
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• pp.352-357
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• 2018

In this paper, the improvement of the conductor temperature calculation algorithm is studied. The allowable current of the underground transmission line is determined by the conductor temperature limit. Usually to calculate the allowable current limit, the conductor temperature is assumed in the most worst environment condition. It is possible to increase the transmission capacity if the actual burial environment is considered. Therefore, in this paper an algorithm is proposed to calculate the conductor temperature by distinguishing two area of a underground transmission line condition - the manhole where the temperature sensor can be installed and the underground transmission line in which the temperature sensor can not be installed easily. When calculating the conductor temperature by the underground line in the pipeline, the existing standard describes each environment as a single soil heat resistance and one ambient temperature. In order to compensate this situation, thermal resistance model that can take into consideration the ground surface temperature and under ground temperature is proposed. It is shown that the accuracy of the proposed model is increased compared with the existing standard calculation result.

• Progress in Superconductivity
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• v.10 no.2
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• pp.108-115
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• 2009

As a participant taking part in the ITER TF conductor R&D program, we developed two toroidal field conductors with variations of conduit thickness resulting in the different void fraction of the conductors. The estimated void fractions of the conductors are 31% and 33%. In this paper we present the details of the TF conductor development and performance test results of them carried out by the measurement of current sharing temperature under cyclic loading. Regarding the conductor development, the internal-Sn-processed $Nb_3Sn$ strand characteristics, strand cabling, twist pitch and characteristics of the conduit materials are presented. For the understanding of the conductor design and performance, the conductor test results are presented and the effect of the conductor design parameters such as void fraction and twist pitch is discussed based on the results.

• International Journal of Precision Engineering and Manufacturing
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• v.6 no.4
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• pp.73-77
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• 2005

Linear motor has been considered to be the most suitable electric machine for linear control with high speed and high precision. Thrust of linear motor is one of the important factors to specify motor performance. Maximum thrust can be obtained by increasing the magnitude of current in conductor and is relative to the sizes of conductor and magnet. However, the magnitude of current and the size of conductor have an effect on temperature of linear motor. Therefore, it is practically important to find optimum design that can effectively maximize thrust of linear motor within limited range of temperature. Finite element analysis was applied to calculate thrust and numerical solutions were compared with experiments. The temperature of the conductor was calculated from the experimentally determined thermal resistance. The ADPL of ANSYS was used for the optimum design process, which is commercial finite element analysis software. Design variables and constraints were chosen based on manufacturing feasibility and existing products. As a result, it is shown that temperature of linear motor plays an important role in determining optimum design.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.1922-1928
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• 2008

The thermal rating of a conductor are maximum continuous current capacity and short time emergency current capacity. The overload operation for a faults have an effect on a conductor lifetime. Its time duration and overload level are limited to facility conditions of transmission lines. The short time emergency current capacity in KOREA observe the KEPCO's DESIGN RULE 1210, but its rules are not included to concept of an allowable short time duration. This papers are described to the calculation concept of short time emergency current capacity considering a time duration and an overload level. And we suggested a operation grouping and its maximum conductor temperature considering facility conditions - conductor lifetime, stability of connection points, conductor height above ground and clearance, in the operating and new T/L.