• 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.

• Progress in Superconductivity and Cryogenics
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• v.3 no.2
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• pp.39-43
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• 2001

For several decades researches and development on superconducting magnetic energy storage(SMES) system have been done for efficient electric power management. Korea Electrotechnology Research Institute (KERI) have developed of a 1MJ , 300kVA SMES System for improving power quality in sensitive electric loads. It consists of an IGBT (Insulated Gate Bipolar Transistor) based power conversion module. NbTi mixed matrix conductor superconducting magnet and a cryostat with HTS current leads. We developed the code fro design of a SMES magnet. Which could find the parameters of the SMES magnet having minimum amount of superconductors for the same store denerby. and designed the 1 MJ SMES magnet by using it . And we have design and fabricated cryostat with kA class HTS current leads for a 1 MJ SMES System. This paper describes the design fabrication and test results for a 1MJ SMES System.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.43-43
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• 2010

HTS(High Temperature Superconductor) cable has a high possibility of practical use due to the possibility of low voltage and high capacity transmission caused by its lower power loss than copper cable. On the other hand, when fault current occurred, resistance increase caused by superconductivity loss, the amount of power supplies has diminished, furthermore, it's necessary to take the possible danger of damage to HITS cable into account. Therefore, an effective plan for dealing with the above problem is to link HITS cable to SFCL. In this study, we researched the possibilities of normal transport current as well as the safety of HITS cable by analyzing the properties of transport current in HITS cable connected with SFCL.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.315-318
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• 2002

The use of high-temperature superconducting materials for transmission cable application is being realized in prototype situation. HTS cable systems have been installed in laboratories and tested successfully around the world. In korea. the first step in development of superconducting cables is distribution system. In this paper. it is proposed the HTS distribution system modeling using ATPDraw and EMTDC programs. In the multilayer conductor, the inner layers have higher impedance than the outer layers. As a result, the current concentrate$ in the outer layers. This paper presents the result of the current distribution in EMTDC.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.817-818
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• 2006

A 2.0T class HTS conduction cooled magnet was designed. Designing of magnet shape was performed through two steps. First step is to find a basic cross section for minimize the amount of conductor used and second step to optimize the coil shape to satisfy the magnetic field homogeneity. The magnetic fields was analyzed with FEM and the critical current value of magnet was also expected with the result of field analysis and the Ic to B curve of Bi-2223 HTS tape.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.6
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• pp.678-682
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• 2004

Generally Bi-2223/Ag tapes have a broad S/N transition region and their sheath is a good electric conductor. In this study, the current distribution between superconductor and metal sheath in HTS tapes were investigated. AC with its peak value above 10 times $I_{c}$ was applied to HTS tapes for around 6 cycles and V-I characteristics were measured. Using the resistance of the sheath and V-I curves, the current distribution between superconductor and metal sheath was calculated. When 150 $A_{p}$ was applied, more than 2/3 of the current flows through superconductor. However, in the case of 304 $A_{p}$, most of the applied current came to flow through the metal sheath at the 6th cycle.e.e.e.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.24-26
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• 2001

The high temperature super-conductor transformer gains interests from the industries. This paper described construction and test results of a 10kVA HTS transformer. Three phase transformer with double pancake windings were constructed. BSCCO-2223 wire, silicon sheet steel core and FRP cryostats were used in that transformer After the test of basic properties of the 3 phase HTS transformer using no load test, short ciucuit test and full load test, continuous operation of 100 hours with pure resistive load has been carried out. Test proved over-load capability and reliability of the HTS transformer.

• 한국초전도학회:학술대회논문집
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• 2009.07a
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• pp.87-87
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• 2009

• Progress in Superconductivity and Cryogenics
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• v.7 no.1
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• pp.47-50
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• 2005

The AC loss is an important issue in the design of the high temperature superconductor (HTS) power cables, which consist of a number of lli 2223 tapes wound on a former. In the cables, the tapes have different critical currents intrinsically. And they are electrically connected to each other and current leads. These make loss measurements considerably complex, especially for short samples of laboratory size. In this work we have prepared a multi-tape conductor composed of Bi-2223 tapes. The at losses of the conductor have experimentally investigated. The loss tests indicate that the effect of tapes critical currents on AC loss measurement in the multi tape conductor is negligible only if currents in the tapes flow uniformly Moreover, the measured tosses of the conductor are in good agreement with the sum of the transport losses in the tapes. However, in the case of non-uniform current distributions, the measured AC losses considerably depend on the current distribution parameter of the positioning of a voltage lead. Thus special cautions should be needed for the measurement of the true AC losses in the short power cable samples.

• Progress in Superconductivity and Cryogenics
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• v.17 no.1
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• pp.17-20
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• 2015

Coated conductor is an important candidate for power cable applications due to its high current density. Even for DC power cable transmission, we must study the transport properties of HTS tapes after slow and fast discharge. In order to evaluate relation of the magnetic field with applied current we developed a scanning magnetic field measurements system by employing a Hall probe. This work presents the measurements of the magnetic fields above a coated conductor by varying applied current pattern. In the work, a transport current of 100 A, less than the critical current, is applied to YBCO coated conductor. We measured the residual magnetic field distributions after cut off the transport current with slow and fast operations. The results show differences of the magnetic field profiles and the corresponding current profiles by an inverse solution from the magnetic field measurement between these two operations because of the hysteresis of coated conductor excited by the transport current.