- Superconducting Materials and Applications
- Physics of Superconductivity and Magnetism
- Electric Motor Design and Analysis
- HVDC Systems and Fault Protection
- Frequency Control in Power Systems
- Magnetic Bearings and Levitation Dynamics
- Particle accelerators and beam dynamics
- High-Voltage Power Transmission Systems
- Magnetic Properties and Applications
- Energy Harvesting in Wireless Networks
- Superconductivity in MgB2 and Alloys
- NMR spectroscopy and applications
- Magnetic properties of thin films
- Advanced NMR Techniques and Applications
- Engineering Applied Research
- Advanced MRI Techniques and Applications
- Building Energy and Comfort Optimization
- Wireless Power Transfer Systems
- Atomic and Subatomic Physics Research
- Aerogels and thermal insulation
- Thermal Analysis in Power Transmission
- Advanced Sensor and Energy Harvesting Materials
- Spacecraft and Cryogenic Technologies
- Fiber-reinforced polymer composites
- Heat Transfer and Optimization
Korea Maritime and Ocean University
2021-2025
Illinois Institute of Technology
2024
State Street (United States)
2024
Rensselaer Polytechnic Institute
2020-2022
Korea Basic Science Institute
2015-2020
Pusan National University
2005-2019
Korea Testing Laboratory
2014-2015
Yonsei University
2010-2014
Korea Evaluation Institute of Industrial Technology
2014
Gyeongsang National University
2003
This paper reports a study on BSCCO and ReBCO HTS (high temperature superconducting) test coils, layer-wound double-pancake, with without turn-to-turn insulation. Over current tests were performed in bath of liquid nitrogen to compare stabilities the coils at 77 K. Saturation magnetic fields from NI (no insulation) both ReBCO, was observed owing bypassing through contacts local quenches operating currents higher than their critical currents. In global occurred coil quench recoveries during...
Recently, studies of partially insulated, high-temperature superconducting (HTS) coils have shown application in the design and construction compact, stable self-protecting HTS coils. This article presents electrical characteristics based on turn-to-turn inserted materials conditions. Three co-wound pancake were fabricated tested. Each coil was with Kapton, stainless steel copper tape at every fourth turn winding. Tested tape, without insulation control group. Charge–discharge,...
A flux pump is a kind of power source that energizes superconducting magnets usually embedded in the cryogenic system. Therefore, heat loss through current leads eliminated, allowing for more efficient cooling design. winding technique, so-called "wind-and-flip," had been proposed by authors to realize jointless HTS coil perfect resistanceless closed loop, which may enable induce persistent an wound with second-generation tape. In this paper, we investigated charging/discharging...
A conduction-cooled 3 T 100 mm winding bore multi-width and no-insulation (NI) all-REBCO magnet was designed, constructed tested at 13 K. The consists of a stack double pancake (DP) coils wound with, for the first time, REBCO tapes having 1 μm thick layer stainless steel, named 'metallic cladding', that surrounds in hermetic way to substantially reduce NI charging delay. After construction, cooled down target operating temperature K using two-stage pulse-tube cryo-cooler. During...
This paper presents a design of 35 T 40 mm winding diameter no-insulation standalone magnet that consists stack 52 double pancake (DP) coils wound with multi-width REBCO tapes. The inner and outer diameters height the are mm, 221.6 628 respectively. It is designed to generate at an operating current (I op) 179.8 A in bath liquid helium 4.2 K. All DP will be 'dry' without epoxy, making turns within essentially 'self-supporting,' which effective reduce magnetic stress. To charging time...
A single pancake no-insulation (NI) coil was wound in a hermetic way with REBCO tape having thin (1–2 μm) cladding layer of stainless steel. With an electric heater embedded at the innermost turn coil, heater-induced quench tests were performed under background field 15 T bath liquid helium 4.2 K. Despite large average contact surface resistance 1.63 cm2 times larger than those pure NI coils, 'thermal recovery' observed current density (Je) below 700 mm−2 mainly due to local sharing. The...
This paper reports the feasibility of impregnation no-insulation (NI) high-temperature superconducting (HTS) coils using an electrically conductive epoxy resin. Recently, several studies HTS without turn-to-turn insulation have been reported for field used in rotating machines such as motors and generators. The NI winding technique enhances thermal stability coil requiring complicated protection techniques because quench current is automatically bypassed through contacts within coil....
Electric vehicle (EVs), which use an electric motor, are expected to replace internal combustion engine vehicles. However, date EVs not highly attractive consumers due their unsatisfactory battery charging characteristics and high cost. In particular, the existing conductive method makes it more difficult spread inconvenience of risk shock. The wireless power transfer (WPT) system can eliminate all troubles EVs. WPT systems in have large air gaps between transmitter coil receiver coil,...
This paper deals with design and operating tests of prototype hybrid superconducting fault current limiter (SFCL) which is series connected non-inductive solenoid resistive coil asymmetric non-inductively wound coils. The role SFCL for reducing the in first swing. Moreover, can reduce a load dielectric strength SFCL. Two kinds high temperature superconductor (HTS) wires were used to fabricate HTS coil. These had different quench characteristics such as critical n-value. Unbalanced...
Abstract In this study, we investigated the effects of solution characteristics on electrospinning behavior and nanoweb structure. We prepared a polyvinylidene fluoride (PVDF) by varying ratios N,N -dimethylformamide (DMF) acetone in solvent fabricated nanowebs electrospinning. determined PVDF with respect to ratio solvent. The were confirmed using high-speed camera. found significant differences behavior. Thus, effect difference morphology structural properties nanoweb.
Contactless power transfer (CPT) technology is an available option to realize the possibility of delivery and storage with connector-free devices across air gap. The CPT system based on a strong resonance coupling, which consists four separate coils same frequency, can possibly exchange energy within 2 m. We propose combination HTS receiver coils, call it superconducting contactless (SUCPT) system. SUCPT technique expected be noble for transferring electric from room temperature very low...
A 3-T 100-mm winding bore conduction-cooled REBCO magnet has been designed, constructed, and tested. It consists of a stack double pancake coils wound with metallic cladding (MC) tapes, for which 1-2 μm stainless steel was clad in hermetic way around the tapes. This approach, first proposed by SuNAM Company Ltd. 2015, is expected to substantially reduce charging time delay no-insulation magnet, turn will be effective manipulation screening currents such as improve field homogeneity magnets,...
We present a recently developed shimming method that uses system of room-temperature (RT) orthogonal coils to improve the spatial field homogeneity high-resolution nuclear magnetic resonance (NMR) and imaging (MRI) superconducting magnets. Conventional RT methods require recursive routines mapping shim coil current adjustments, which lead less effective time-consuming process. In this paper, we introduce new utilizes process gradual automatic search find an optimal operating point with...
This paper examines the effects of alternating fields on high-temperature superconducting (HTS) coils according to winding insulation condition. Alternating can occur in synchronous machines (armature reaction, faults) and other devices. In machines, affect operational characteristics machine field coil. Therefore, a method reducing is necessary design. this study, HTS coil condition were experimentally evaluated. The experimental results show that made using no-insulation technique be...
This paper reports calculation and measurement of magnetic fields from a 3 T 66-mm room-temperature bore no-insulation high-temperature superconductor nuclear resonance (NMR) magnet with screening current manufacturing uncertainty considered. The reached its full field, under conduction-cooling environment at 17 K. measured along the axis showed substantial discrepancy to originally designed ones. In simulation, dimensions 66 total single pancake coils were used in consideration errors each...
The prototype high-T <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> superconducting electromagnet (HTS-EM) for high-speed EMS Maglev was successfully demonstrated in system up to the vehicle running speed of 500 km/h. EM designed interface with existing propulsion used German Maglev. rating levitation force correspond weight at a 20 mm gap. Electromagnetic forces were simulated and compared test results order verify design feasibility...
In this paper, the overhang effect of a homopolar synchronous generator with high-temperature superconducting (HTS) field winding is analyzed. Homopolar topology can be used to implement stationary winding, which advantageous for electrical rotating machine applications that rotate at relatively high speed. The has an axial-winding radial-flux structure, unlike general heteropolar machines have radial-winding structure. Therefore, in order analyze characteristics more accurately, use 3D...
This paper presents a dynamic characteristic analysis of an electrical rotating machine that applies no-insulation (NI) high-temperature superconductor (HTS) field coils. The HTS applying coils has high power density compared to conventional machines utilize normal conductor coils, meaning it great potential for next-generation mobility applications such as electric ships and aircraft. Recently, several studies have reported the possibility solving quench protection problem coil, which is...