• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
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• pp.101-102
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• 2006

We investigated the characteristics of flux-lock type superconducting fault current limiter (SFCL) by the fault cycles. Since the recovery characteristics of a superconducting element in the flux-lock type SFCL were dependent on the winding' direction between two coils, the analysis for the recovery characteristics of this type SFCL together with the current limiting characteristic is necessary to apply it to power system. As the fault cycles was increased from 1 cycle to 5 cycles, the initial limiting current ($I_{ini}$) and quench characteristic were mostly same. As the fault period increases, the recovery time of the superconducting element increases. The consumed energy and recovery characteristics in a superconducting element show the same tendency.

• 전기학회논문지
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• 제63권11호
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• pp.1602-1607
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• 2014

This paper deals with the design and property analysis of 7kW-class small-scaled superconducting Linear Synchronous Motor (LSM) and testing equipment for a number of performance pre-tests prior to the development of coreless-type superconducting LSM suitable for 600km/h very high speed train. First, the basic design and property analysis are conducted before developing a small-scaled superconducting LSM model with 2-pole superconducting electromagnets, and additionally the cost-down design of the superconducting electromagnets is conducted to use less high-Tc superconducting wire. Finally, the superconducting magnet coil span is selected at 120mm, and input ground armature current of 670Aturns is required to produce 44.7N of thrust based on research findings.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2005년도 High Temperature Superconductivity Vol.XV
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• pp.73-73
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• 2005

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.344-345
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• 2009

The flux-coupling type superconducting fault current limiter(SFCL) is composed of a series transformer and superconducting unit of the YBCO coated conductor. The primary and secondary coils in the transformer were wound in series each other through an iron core and the YBCO coated conductor was connected with secondary coil in parallel. In a normal condition, the flux generated from a primary coil is cancelled out by its structure and the zero resistance of the YBCO thin films. When a fault occurs, the resistance of the YBCO coated conductor was generated and the fault current was limited by the SFCL. In this paper, we investigated the fault current limiting characteristics according to turn ratio in the flux-coupling type SFCL. The experiment results that the fault current limiting characteristics was improved according to turn ratio.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.393-395
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• 2006

We investigated the operational characteristics of the hybrid-type superconducting fault current limiter (SFCL) according to the serial and parallel connections of secondary circuits. The hybrid-type SFCL consists of a transformer, which has a primary winding and several secondary windings with $YBa_2Cu_3O_7$ films connected in series and parallel. In order to increase the capacity of the SFCL, the serial connection between each current limiting unit is necessary. The hybrid-type SFCL with the serial connection in secondary circuits could show superior characteristics than those of the parallel connections in the current limiting and quench time. The resistances generated in the superconducting units were also lowered at the parallel connections. We confirmed that the parallel connection reduced the power burden of each superconducting unit under the same conditions because of the simultaneous quenching between superconducting units.

• 전기학회논문지P
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• 제58권1호
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• pp.85-89
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• 2009

We investigated the quench characteristics in accordance with increase of turns number of trigger coil and shunt resistance of matrix-type superconducting fault current limiter (SFCL) with $2{\times}3$ array. The matrix-type SFCL consists of the trigger part to apply magnetic field and the current-limiting part to limit fault current. The fault current limiting characteristics according to the increase of magnetic field and applied voltage were nearly same. This is because the application of magnetic field hasn't an affect on total impedance of the SFCL. When turns number of a reactor increased, the voltage difference between two superconducting units in the current-limiting part according was decreased. The resistance difference generated in two superconducting units was also decreased. Therefore, we confirmed that the differences of the critical behaviors between superconducting units were reduced by application of magnetic field. By this results, we could decide the optimum turns number of reactor to apply magnetic field.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 1999년도 High Temperature Superconductivity Vol.IX
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• pp.112-114
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• 1999

Superconducting multiplexer consisting of hairpin type filters has been designed for the reduction of the physical size of the device. Pulsed laser deposition with a Nd:YAG laser has been used to grow high quality YBCO superconducting films on MgO substrates. Multiplexer has been designed to have the center frequencies at 13.6 CHz and 13.9 GHz on MgO substrate with the size of 20 ${\times}$ 20 ${\times}$ 0.5mm$^3$. It is possible to implement superconducting multiplexer having two passbands on the limited 20 ${\times}$ 20 ${\times}$ 0.5mm$^3$ MgO substrate by adopting hairpin type filters. This type of superconducting device will be useful for the integration of microwave subsystem.

• 전기학회논문지P
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• 제57권3호
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• pp.343-348
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• 2008

We investigated the quench characteristics accordance with increase of turns and applied voltage of matrix-type superconducting fault current limiter (SFCL) with $1{\times}3$ matrixes. The matrix-type SFCL consists of the trigger part to apply magnetic field and the current-limiting part to limit fault current. The fault current limiting characteristics according to the increase of magnetic field and applied voltage were nearly same. This is because the application of magnetic field has not an affect on total impedance of SFCL. When number of turns of reactor increased, the voltage difference between two superconducting units in the current-limiting part according was decreased. The resistance difference generated in two superconducting units also was decreased. Therefore, we confirmed that the differences of critical behaviors between superconducting units by application of magnetic field were decreased. By this results, we could be decided the optimum number of turns of reactor to apply magnetic field.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.288-288
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• 2008

The flux-coupling type superconducting fault current limiter(SFCL) is composed of a series transformer and superconducting unit of the YBCO thin films. The primary and secondary coils in the transformer were wound in series each other through an iron core and the YBCO thin film was connected with secondary coil in parallel. In a normal condition, the flux generated from a primary coil is cancelled out by its structure and the zero resistance of the YBCO thin films. When a fault occurs, the resistance of the YBCO thin films was generated and the fault current was limited by the SFCL. In this paper, we investigated the fault current limiting characteristics according to fault current level in the flux-coupling type SFCL. The experiment results that the fault current limiting characteristics was improved according to increase of the fault current level.

• 전기학회논문지
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• 제59권7호
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• pp.1320-1326
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• 2010

In this paper, we develop a design methodology of granular-based neurocomputing networks realized with the aid of the clustering techniques. The objective of this paper is modeling and evaluation of approximation and generalization capability of the Linear-Type Superconducting Power Supply (LTSPS). In contrast with the plethora of existing approaches, here we promote a development strategy in which a topology of the network is predominantly based upon a collection of information granules formed on a basis of available experimental data. The underlying design tool guiding the development of the granular-based neurocomputing networks revolves around the Fuzzy C-Means (FCM) clustering method and the Radial Basis Function (RBF) neural network. In contrast to "standard" Radial Basis Function neural networks, the output neuron of the network exhibits a certain functional nature as its connections are realized as local linear whose location is determined by the membership values of the input space with the aid of FCM clustering. To modeling and evaluation of performance of the linear-type superconducting power supply using the proposed network, we describe a detailed characteristic of the proposed model using a well-known NASA software project data.