• 한국초전도ㆍ저온공학회논문지
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• 제6권2호
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• pp.20-24
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• 2004

Bi-2223 wire, the first-generation high temperature superconducting (HTS) wire, was successfully commercialized and various electrical machinery and equipment are actively being developed in many countries. Because its critical current is too small to realize the lossless conducting part of electric power system with a HTS wire, multi-HTS paths are used to enlarge the critical current of HTS system. Though the resistance generated in HTS wire by transport current is very small, the difference of it in multi-path is the additional reason which causes the non-uniform current sharing in multi-HTS path except the well known reason, the difference of inductance between each path. In this paper, experimental research on current sharing of multi-strand and multi-stacked HTS wire was implemented. The whole critical current of multi-HTS paths is not equal to sum of critical current of each path because of non-uniform current sharing occurred in this paths. It was verified experimentally that Bi-2223 wires have different resistance generated by same transport current even if they was manufactured in same progress of work. Current sharing phenomenon was affected by difference of resistance and self and mutual inductance.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.245-249
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• 2009

According to the increase of intelligent vehicles many automotive electric components are installed. The wire harness which connects those also increases. The crimping process for compressing the copper wire bundle into the terminal is a key process to assure the good quality of wire harness. For the case of inadequate forming condition many shape failures such as less-filling, over-filling are happen in the crimping process. Even though the quality of crimping shape is satisfactory the quality check for electrical resistance of wire harness is sometime not satisfied the qualification due to large variation of electrical resistance of wire harness under climate test. This large variation is thought to be related with the malfunction automotive electric system and caused by the internal stress of wire, which occurred during the crimping process. In this paper we develop the 3D-FEM simulation scheme and design methodology of optimum terminal shape. Also the effect of terminal shape on the residual stress is discussed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.108-110
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• 2000

The aim of this paper is to investigate the effect of Al and Ti on microstructure of Fe-Cr-Al alloy systems for applying electrical resistance wires of electrical furnace. From the preliminary study, the amount of recovered addition elements increased in the case of both vacuum and Ar-atmosphere melting than that in the case of air-atmosphere melting. Also, optimum Cr content for good performance at high temperature was approximately 24wt% from the observation of microstucture. The precipitates of Fe-Cr, Al-Cr and Al phases were observed, adding Al and Ti. Especially, Sharp rectangular shapes of precipitates were observed with increasing amount of Ti.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.151-151
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• 2009

A enameled wire may have better corona-resistance when its coating material contains nano-sized inorganic particles. However, industrial applications are still limited because an aggregation between nanofillers may happen during coating processes. In this study we use a novel scheme of surface modification with silane on silica nanoparticles using sonochemical reaction where composition and surface density of silanes can be controlled in order to reduce particle-particle attractive interaction. Functionalized nanoparticles are evenly dispersed in the matrix confirmed by SEM and energy dispersive x-ray analysis. Dielectric strength and thermal resistance of the nanocomposite wires are improved while flexibility of the wire maintains.

• 전기학회논문지P
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• 제56권2호
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• pp.109-114
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• 2007

This paper summarize about the auxiliary electrode measured a ground resistance. The method to measure a ground resistance is the fall-of-potential method to using an auxiliary electrode. And an auxiliary electrode must be set up on the ground. Today it is so difficult to set up the auxiliary electrode on the ground because of many concrete building and many paved roads. So this paper is regarding a trust analysis of the ground resistance measurement by the substitute auxiliary electrode. It substituted a iron structure around the building, a neutral line multiplex ground to earth, a wire net for auxiliary electrode. This information is confirmed bv compared with the measurement value.

• 한국전기전자재료학회논문지
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• 제18권12호
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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.

• 한국전기전자재료학회논문지
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• 제35권2호
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• pp.172-177
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• 2022

The quench voltage of the second-generation superconducting wire is affected by the resistivity characteristics of the stabilization layer. The specific resistance of the stabilization layer can be changed by the deposition process using RF magnetron sputtering. In this paper, a thin film made of a homogeneous material (Ag) and a dissimilar material (Cu) was deposited on the stabilization layer of the second-generation superconducting wire through RF magnetron sputtering. We found that the specific resistance was reduced by increasing the thickness of the stabilization layer. The reduction in the resistivity of the stabilization layer led to a decrease in the quench voltage of the second-generation superconducting wire. We suggest that various characteristic changes of the second-generation superconducting wire can be expected through the successful change in the resistivity of the stabilization layer of the proposed deposition process.

• 전기학회논문지
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• 제57권4호
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• pp.653-659
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• 2008

This paper describes the design of high power transistor packages using high power chip transistor dies, chip capacitors and a new wire bonding technique. Input impedance variation and output power performances according to wire inductance and resistance for internal matching are also discussed. A multi crossing type(MCT) wire bonding technique is proposed to replace the conventional stepping stone type(SST) wire bonding technique, and eventually to improve the output power performances of high power transistor packages. Using the proposed MCT wire bonding technique, it is possible to design high power transistor packages with highly improved output power compared to SST even the package size is kept to be the same.

• 전기학회논문지P
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• 제59권2호
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• pp.191-196
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• 2010

The electricity distribution system in Korea is adopting a multi-grounding system. Protection of this distribution system against lightning is performed by installing overhead ground wires over the high voltage wires, and connecting the overhead ground wires to the ground every 200 m. The ground resistance in this system is limited not to exceed $50\Omega$ and overhead ground wire and neutral wire are multiple parallel lines. Although overhead ground wire and neutral wire are installed in different locations on the same pole, this circuit configuration has duplicated functions of providing a return path for unbalanced currents and protecting the distribution system against induced lightning. Therefore, the purpose of this study is to analyze the induced lightning shielding effect according to the neutral wire installation structure of a 22.9kV distribution line in order to present a new 22.9kV distribution line structure model and characteristics. This study calculated induced lightning voltage by performing numerical analysis when an overhead ground wire is present in the multi-grounding type 22.9kV distribution line structure, and calculated the induced lightning shielding effect based on this calculated induced lightning voltage. In addition, this study proposed and analyzed an improved distribution line model allowing the use of both overhead wire and neutral wire to be installed in the current distribution lines. The result of MATLAB simulation using the conditions applied by Yokoyama showed almost no difference between the induced lightning voltage developed in the current line and that developed in the proposed line. This signifies that shielding the induced lightning voltage through overhead wire makes no difference between current and proposed distribution line structures. That is, this study found that the ground resistance of the overhead wire had an effect on the induced lightning voltage, and that the induced lightning shielding effect of overhead wire is small.

• 한국전기전자재료학회논문지
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• 제28권10호
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• pp.625-629
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• 2015

The second-generation HTS wire its YBCO coated conductor is widely used in the superconducting power apparatus. The YBCO coated conductor uses the normal-superconducting junction to increase the transport capacity of superconducting power apparatus when it is applied. The normal-superconducting junction can be a cause of reducing the stability of the superconducting power apparatus when a fault current is applied. Thus, in this study we have conducted the effect analysing normal-superconducting junction for the fault current using transport current and quench resistance. From the experimental results when a fault current is applied, the effect on the normal-superconducting junction is reduced the larger the amplitude of the fault current and is helpful to maintain the thermal stability of the HTS wire.