• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.12
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• pp.1152-1158
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• 2005

New conductor is developed by using high strength nonmagnetic steel(NM) wire as the core of overhead conductor. This conductor is called ACNR overhead conductor(Aluminum Conductor Nonmagnetic Steel Reinforced). Formed by the combination of aluminum alloy wire and high strength nonmagnetic steel wire, it has about the same weight and diameter as conventional ACSR overhead conductor. To enhance properties beneficial in an electrical and mechanical conductor during the process of high strength nonmagnetic steel wire, we made a large number of improvements and modifications in the working process, aluminum cladded method, and other process. ACNR overhead conductor, we successfully developed, has mechanical and electrical properties as good as or even better than conventional galvanized wire. Microstructure of raw material M wire was austenite and then deformed martensite after drawing process. Strength at room temperature is about $180kgf/mm^2\~200kgf/mm^2$. NM wire developed as core of overhead conductor shows heat resistant characteristics higher than that of HC wire used as core of commercial ACSR overhead conductor, Strength loss was not occur at heat resistant test below $600^{\circ}C$. Fatigue strength of vibration fatigue is about $32kgf/mm^2\~35kgf/mm^2$ and that of tension-tension fatigue is $90kgf/mm^2\~120kgf/mm^2$ which is $50\~65\%$ of tensile strength.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1035-1038
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• 2007

We designed and manufactured a 1.8T high temperature superconducting(HTS) insert coil for a NMR magnet operated at 4.2 K. Suitable HTS superconductor and HTS coil were carefully designed and developed. We have selected multi-filamentary Bi2223 conductor fabricated by American Superconductor Corporation(AMSC). The selected conductor consists of Bi2223 filaments of 55, silver stabilizer and stainless steel reinforcement tapes. Therefore, it shows good hoop strength as well as compression tolerance. The conductor has a tape cross-section of 0.31mm x 4.8mm. the Bi2223 conductor shows large anisotropy of critical current. The critical current of conductor in magnetic field parallel to the flat surface are much higher than that in magnetic field perpendicular. The HTS coil has an inner diameter of 78 mm, an outer diameter of 127 mm and a coil length of 600 mm. In this paper, the detailed design, fabrication and test results on the HTS insert coil are presented.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.12
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• pp.1159-1165
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• 2005

New conductor is developed by using high strength nonmagnetic steel(NM) wire as the core of overhead conductor This conductor is called ACNR overhead conductor(Aluminum Conductor Nonmagnetic Steel Reinforced). Formed by the combination of aluminum alloy wire and high strength nonmagnetic steel wire, it has about the same weight and diameter as conventional ACSR overhead conductor. To enhance properties beneficial in an electrical and mechanical conductor during the Process of high strength nonmagnetic steel wire, we made a large number of improvements and modifications in the working process, aluminum cladded method, and other process. ACNR overhead conductor, we successfully developed, has mechanical and electrical properties as good as or even better than conventional galvanized wire. Microstructure of raw material NM wire was austenite and then deformed martensite after drawing process. Strength at room temperature is about $180kgf/mm^2\~200kgf/mm^2$. The conductivity at 0.78 mm thickness of Aluminum cladded M wire is about $7\%$ IACS higher than $20\%$IACS of HC wire used as core of commercial ACSR overhead conductor. The corrosion resistance is about 3 times higher than that of HC wire.

• Journal of the Korean Society of Safety
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• v.28 no.4
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• pp.38-42
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• 2013

This study performed the quantitative distribution analysis of created voids to an insulator when applying general flame and DC short-circuit current to 2.5 $mm^2$ HIV (600 V Grade Heat-Resistant Polyvinyl Chloride Insulated Wires). The diameter of cross-section of HIV normal product and the radius of conductor were measured to be 3.3 mm and 1.8 mm. The exterior of HIV exposed to general flame showed severe carbonization and its interior exhibited voids created by dechlorination reaction. This study observed the characteristics that, when the shortcircuit current applied for 2 seconds from a DC 12 V lead battery, the conductor and neighboring insulator were melted, causing the insulator adhering to the conductor. On average, 87 voids were created on 10 mm of the HIV. The average diameter of voids was 0.25 mm. In addition, it was found that, when the short-circuit current applied for 4 seconds, the interior of insulator in contact with conductor severely carbonized and showed exfoliation phenomenon. On average, 47 voids were created, with more voids at the bottom. The average diameter of voids was 0.20 mm. When the short-circuit current for 6 seconds, most parts of upper part of conductor was carbonized, 20 voids were created. The average diameter of voids was measured to be 0.24 mm. It could be seen that the created voids received little influence by the type of energy source and the number of created voids was reduced as the energy supply time increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05a
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• pp.35-39
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• 2002

A defect detection test was performed for a conductor using a amorphous wire sensor head. A uniform magnetic field was applied in the space between the most inner conductors of a spiral-typed coil. The conductor with a defect was placed on the space between the most inner conductors of spiral-typed coil. The defect can be detected from the differences of induced voltage measured in the vicinity of gap of the conductor. The induced voltage difference of 2.5mV was measured in the gap vicinity of the 1mm thick conductor having 0.5mm gap in the frequency region of 100kHz~600kHz.

• Journal of Mechanical Science and Technology
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• v.16 no.2
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• pp.227-234
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• 2002

Large superconducting magnets such as ITER (International Thermonuclear Experimental Research) or KSTAR (Korean Superconducting Tokamak Advanced Research) magnet system adopted a cable-in-conduit conductor (CICC) using a forced-flow cooling system. Main optimization criteria for the conductor design of superconducting magnet system are stability margin and CICC cooling requirements. A zero-dimensional method is applied for the calculation of stability and the conductor optimization. In order to increase conductor performance, three different strands, ITER HP-I and HP-II, and KSTAR HP-Ⅲ, are tested. The strand characteristics of KSTAR HP-Ⅲ are measured in the Samsung's PPMS and Jc measurement system, and applied for this study. Also, the strand diameters, 0.81 mm and 0.78 mm are considered for this study, due to design change. Based on this result, the proposed configuration of CICC has been fabricated.

• Progress in Superconductivity and Cryogenics
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• v.12 no.2
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• pp.21-24
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• 2010

This paper deals with numerical analysis on a high-$T_c$ superconducting (HTS) electrodynamic suspension (EDS) simulator according to the variation of the ground conductor conditions. Because the levitation force of EDS system is formed by the magnetic reaction between moving magnets and fixed ground conductors, the distribution of the magnetic flux on a ground conductor plays an important role in the determining of the levitation force level. The possible way to analyze HTS EDS system was implemented with 3D finite element method (FEM) tool. A plate type ground conductor generated stronger levitation force than ring type ground conductor. Although the outer diameter of Ring3 (335 mm) was larger than that of Ring2 (235 mm), the levitation force by Ring2 was stronger than that by Ring3. Considering the results of this paper, it is recommended that the magnetic flux distribution according to the levitation height and magnet current should be taken into account in the design of the ground conductors.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.61-62
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• 2015

In this paper, a design method for a dual-band compact slot antenna using SRR(split-ring resonator) conductor is studied. The SRR conductor is loaded inside of a rectangular slot of the proposed antenna for dual-band operation. Final design parameters are obtained by analyzing the effects of the gap between the SRR conductor and slot, and the width of the SRR conductor on the input reflection coefficient and gain characteristics. A prototype of the proposed dual-band slot antenna operating at 2.45 GHz WLAN band and 3.40-5.35 GHz band is designed on an FR4 substrate with a dimension of 30 mm by 30 mm.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1159_1160
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• 2009

This paper presents the numerical simulation results on the supercodnucting electrodynamic suspension (EDS) simulator according to the variation of the ground conductor. The levitation force of the EDS system is formed by the reaction between the moving magnet and the fixed ground conductor. The possible way to simulate the EDS system were simulated in this paper by using finite element method (FEM). The static type simulator which consists of the fixed magnet, the fixed ground conductor and the ac current supply system. To verify the characteristics of high speed EDS system with the moving type simulator heavy, large and fast moving ground conductor is needed. The static type simulator can get the characteristics of the high speed EDS system by applying equivalent ac current to velocity, therefore it does not need large moving part. The static type EDS simulator, which can consist of an HTS magnet, the fixed ground conductor(s), an AC power supply and the measuring devices, also test the effect of the shape of the ground conductor easily. The plate type ground conductor made stronger levitation force than ring type ground conductor. Although the outer diameter 335 mm ring type ground conductor (Ring3) was larger than the outer diameter 235 mm ground conductor (Ring2), the levitation force by Ring2 was stronger than that by Ring3. From the calculation results on this paper, the consideration of the magnetic flux distribution according to the levitation height should be included in the process of the ground conductor design.

• Journal of KSNVE
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• v.6 no.1
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• pp.89-95
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• 1996

If the transmission line voltage is greater than 500kV, audible noise (AN) and hum noise (HN) due to corona discharges on the conductor would be an important design factor for the conductor selection of transmission line. Also there is an aeolian noise: wind noise(WN) from the tower and the conductor due to wind. This paper presents the results of a statistical analysis of audible noise, hum noise, aeolian noise of 6-480mm$^{2}$ conductor bundle in KEPRI 765kV Test Transmission Line which was constructed to develop 765kV double circuit AC transmission line for the first time in the world. The result of the analysis shows that 6-480mm$^{2}$ conductor bundle and tower satisfy configuration the audible noise design criterion of 50dB(A).