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Your search keyword '"Wooho Chung"' showing total 8 results
Start Over Author "Wooho Chung" Journal ieee transactions on applied superconductivity
8 results on '"Wooho Chung"'

1. Development of CICC for KSTAR Superconducting Magnet System

Author

Keeman Kim, M.S. Ko, Yong Chu, D.K. Lee, J.Y. Choi, C.S. Kim, Kyungryun Kim, S.J. An, B.S. Lim, I.S. Woo, W.W. Park, G.S. Lee, Y.J. Song, Wooho Chung, Soonil Lee, J.S. Bak, J.J. Joo, N.H. Song, H.K. Park, K. Pak, and D.J. Kim

Subjects
Fabrication, Tokamak, Materials science, Nuclear engineering, Superconducting magnet, Welding, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, law.invention, Conductor, law, KSTAR, Electrical and Electronic Engineering, Electrical conductor, Incoloy
Abstract

The KSTAR (Korea Superconducting Tokamak Advanced Research) superconducting magnet system adopts a superconducting CICC(Cable-In-Conduit Conductor) type conductor. It consists of 16 TF (Toroidal Field) coils and 14 PF (Poroidal Field) coils and it also uses two different types of CICCs-Nb3Sn cable with Incoloy 908 conduit and NbTi cable with 316LN stainless-steel conduit. A special CICC jacketing system is developed for the KSTAR CICC fabrication: the tube-mill process, which consists of forming, welding, sizing and squaring procedure. The cabling process for TF and PF superconducting cable and the fabrication process of each CICCs (TF CICC and PF CICC) is described. The welding of conduit materials are also discussed. The fabrication results such as the geometrical specification, micro structure and the void fraction will be discussed

Published
2006
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2. The magnetic properties of the ferromagnetic materials used for HTS transformers at 77 K

Author

Sungkeun Baang, Keeman Kim, Min Chen, Liye Xiao, Yunjia Yu, Qiuliang Wang, and Wooho Chung

Subjects
Materials science, Amorphous metal, Silicon, Physics::Instrumentation and Detectors, chemistry.chemical_element, engineering.material, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, law.invention, Amorphous solid, Condensed Matter::Materials Science, Nuclear magnetic resonance, Magnetic core, chemistry, law, Magnet, engineering, Amorphous metal transformer, Electrical and Electronic Engineering, Composite material, Transformer, Electrical steel
Abstract

The properties of the magnetic materials, such as the amorphous alloys and the grain-oriented silicon steels, are essential to the design of high-temperature superconducting transformers. In this paper the magnetic properties and the loss characteristics of different ferromagnetic materials are measured at liquid nitrogen temperature. It is shown from experimental results that at 77 K the saturation flux density of the amorphous metal is about 0.3 T lower than that of the silicon steel, and the loss of amorphous metal is 4 times less than that of the silicon steel. Since the losses of materials at 77 K are higher than those of at room temperature, it is not economical to immerse the transformer core in liquid nitrogen.

Published
2003
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3. Magnetic field analysis of HTS transformer windings with high currents

Author

Min Chen, Liye Xiao, Sungkeun Baang, Yunjia Yu, Keeman Kim, Qiuliang Wang, and Wooho Chung

Subjects
Materials science, High-temperature superconductivity, Condensed matter physics, Numerical analysis, Demagnetizing field, Mechanical engineering, Condensed Matter Physics, Finite element method, Electronic, Optical and Magnetic Materials, law.invention, Magnetic field, Transformer windings, law, Electrical and Electronic Engineering, Anisotropy, Transformer
Abstract

The leakage magnetic field in HTS transformer windings fabricated by Bi-2223 tapes decreases the critical current and increases the ac losses in the tapes. Because of the anisotropy of the HTS tape, the numerical analysis of the radial component of the leakage field is especially important. In this paper the influence of the core structure and the winding configuration on the stray field is studied by finite element method, and some suggestions for improving the leakage field distribution are presented to make HTS transformers more efficient.

Published
2003
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4. Thermo-Hydraulic Analysis of the KSTAR Central Solenoid Model Coil.

Author

Wooho Chung, Soohwan Park, Qiuliang Wang, Sangkwon Jeong, Cheon Seog Yoon, Yeong-Kook Oh, Keeman Kim, Joo Shik Bak, and Lee, G. S.

Subjects
*SOLENOIDS, *HYDRAULICS, *MAGNETS, *HELIUM, *SUPERCONDUCTORS, *SUPERCONDUCTING magnets
Abstract

The Korea Superconducting Tokamak Advanced Research (KSTAR) Central Solenoid Model Coil (CSMC) has been developed to validate the design of KSATR CS coil. The thermo-hydraulic characteristics were analyzed for the KSTAR CSMC. The major thermo-hydraulic parameters of the coil are AC losses, strand temperature, coolant temperature, pressure drop and temperature margin. A numerical code has been developed for the thermo-hydaulic analysis of the KSTAR CSMC according to the operating conditions. In this paper, the description of the thermo-hydraulic analysis models and analysis results of CSMC are presented. The total energy deposition due to AC losses in CSMC winding will induce a flow reversal of supercritical helium. The minimum temperature margin is estimated approximately 0.5 K. The maximum temperature in CSMC winding is about 7.6 K. [ABSTRACT FROM AUTHOR]

Published
2005
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5. Operating Characteristics of the KSTAR Superconducting TF Coil.

Author

Wooho Chung, Qiuliang Wang, Sangkwon Jeong, Cheon Seog Yoon, Hyunki Park, and Kim, Keeman

Subjects
*SUPERCONDUCTORS, *SOLID state electronics, *CRYOELECTRONICS, *VACUUM, *ELECTRIC discharges, *LOW temperature engineering
Abstract

The Korea superconducting Tokamak Advanced Research (KSTAR) device, a steady-state-capable advanced Tokamak, is to be built in Korea. The KSTAR device is made up of 16 toroidal field (TF) and 14 poloidal field (PF) superconducting coils. A simulation code for the transient operation of the KS TAR TF and PF coils is developed. For stable Tokamak operation, the operating characteristics of the KSTAR superconducting magnet system are studied for operation scenario. We calculated the temperature margin of superconducting cables, cryogenic flow parameters and the heat deposition in TF and PF coils. The effect of the three-dimensional heat conduction and the eddy current loss in the supporting structure and vacuum chamber of KSTAR is also included. [ABSTRACT FROM AUTHOR]

Published
2004
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7. Influence of Inlet Pressure and Mass Flow Rate on the Temperature Rise of Superconducting Strands in SSTF Under the Normal Operating Conditions.

Author

Cheon Seog Yoon, Qiuliang Wang, Yeong Sung Suh, Sun Woong Choi, Wooho Chung, Hyunki Park, and Keeman Kim

Subjects
SUPERCONDUCTING magnets, LOW temperature engineering
Abstract

Examines the influence of cryogenic parameters on the temperature margin of superconducting magnets. Reduction of mass flow rate; Peak temperature rise; Cooling condition of the superconducting strands.

Published
2002
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