Partial insulation of GdBCO single pancake coils for protection-free HTS power applications

Choi, Yoon Hyuck; Hahn, Seungyong; Song, Jung-Bin; Yang, Dong; Lee, H G

doi:10.1088/0953-2048/24/12/125013

Cited by 99 publications

(45 citation statements)

References 11 publications

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“…No and partial insulation (NI/PI) winding techniques can be considered as a way of HTS field coil windings. These winding techniques are developed by MIT's francis bitter magnet laboratory and introduced and studied in [32][33][34][35][36][37][38]. The key benefits of NI/PI technique detail as follows: a) thermal stability enhancement, b) self-protecting, c) compactness (enhanced overall current density), and d) mechanical robustness compared with insulated counterpart.…”

Section: Stability Of Hts Magnets For Field Coilmentioning

confidence: 99%

Status of the technology development of large scale HTS generators for wind turbine

Le¹,

Kim²,

Kim³

et al. 2015

Progress in Superconductivity and Cryogenics

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Large wind turbine generators with high temperature superconductors (HTS) are in incessant development because of their advantages such as weight and volume reduction and the increased efficiency compared with conventional technologies. In addition, nowadays the wind turbine market is growing in a function of time, increasing the capacity and energy production of the wind farms installed and increasing the electrical power for the electrical generators installed. As a consequence, it is raising the wind power energy contribution for the global electricity demand. In this study, a forecast of wind energy development will be firstly emphasized, then it continue presenting a recent status of the technology development of large scale HTSG for wind power followed by an explanation of HTS wire trend, cryogenics cooling systems concept, HTS magnets field coil stability and other technological parts for optimization of HTS generator design -operating temperature, design topology, field coil shape and level cost of energy, as well. Finally, the most relevant projects and designs of HTS generators specifically for offshore wind power systems are also mentioned in this study.

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Section: Stability Of Hts Magnets For Field Coilmentioning

confidence: 99%

Status of the technology development of large scale HTS generators for wind turbine

Le¹,

Kim²,

Kim³

et al. 2015

Progress in Superconductivity and Cryogenics

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“…First, all the NI GdBCO test magnets to date have proven self-protecting [11][12][13][14][15][16][17][18] at 4.2 K and 77 K; the largest has a center field of 4 T with a 140-mm winding diameter. 11 Nevertheless, the self-protecting feature of a "large" NI magnet, such as our 100 T, needs further verification.…”

Section: The 100 T Is Wound With Gdbco Tape Manufactured Bymentioning

confidence: 99%

“…[9][10][11][12][13] (2) NI DP coils have proven self-protecting. [9][10][11][12][13] Currently, more NI coils are being tested to further assess their self-protecting feature. (3) For this 100 T, the GdBCO tape is assumed to remain superconducting and capable of carrying an operating current of 600 A at 4.2 K, which must be verified.…”

Section: -mentioning

confidence: 99%

First-cut design of an all-superconducting 100-T direct current magnet

Iwasa

Hahn

2013

Applied Physics Letters

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A 100-T magnetic field has heretofore been available only in pulse mode. This first-cut design demonstrates that a 100-T DC magnet (100 T) is possible. We base our design on: Gadoliniumbased coated superconductor; a nested-coil formation, each a stack of double-pancake coils with the no-insulation technique; a band of high-strength steel over each coil; and a 12-T radial-field limit. The 100 T, a 20 mm cold bore, 6-m diameter, 17-m height, with a total of 12 500-km long superconductor, stores an energy of 122 GJ at its 4.2-K operating current of 2400 A. It requires a 4.2-K cooling power of 300 W. A 100-T DC field, one million times the earth field, is more than double 45 T, 1 the highest DC field created to date. Upon completion, a 32-T magnet at the National High Magnetic Field Laboratory (NHMFL) will achieve the highest DC field by an all-superconducting magnet.2,3 Fields greater than 45 T have been beyond DC magnet technology. Simply stated, this is because no electrical conductor meets two requirements for generation of a >45-T continuous field: high mechanical strength and good electrical conductivity. Copper is unable to withstand the high magnetic stresses. Steel can cope with the large stresses, as has been demonstrated by pulse magnets, 4,5 but its large electrical resistivity leads to huge Joule heating that rapidly overheats the steel, reducing its strength and thereby forcing >45-T steel magnets to operate only in pulse mode. 6,7 Although the range of experiments that can be done with pulsed fields continues to expand, 7 the words of Francis Bitter remain valid, "there are many experiments that are extremely difficult or impossible to perform in a hundredth of a second" 8 as a reason to drive the maximum DC field limit much higher. Our 100-T DC magnet (100 T) uses a superconductor of sufficient strength, with the winding reinforced by overbands of high-strength stainless steel. With electrical resistivity anchored to zero, one inherent weakness of the pulse magnet is eliminated.The two crucial design issues in high-field superconducting magnets are: (1) mechanical integrity; and (2) protection. In this first-cut design, based on the no-insulation (NI) technique, 9-18 we assumed 100 T self-protecting; thus, we focused chiefly on mechanical stress. Our key design approach is fourfold. The 100 T is wound with GdBCO tape manufactured bySuperPower, specifically 12-mm wide and 95-lm thick, comprising 50-l thick Hastelloy substrate (room-temperature yield stress and strain, respectively, of 970 MPa and 0.95% 19 ), two 20-lm thick electroplated copper layers, and 5-lm thick remainder (1-lm thick GdBCO layer and other materials). 2. The 100 T consists of 39 nested coils, each a stack of double-pancake coils (DPs) wound with the NI technique.3. To keep the peak tensile stress on GdBCO tape to 700 MPa at 4.2 K, each DP is reinforced over its outer diameter with a high-strength stainless steel band (overband) of 300-K ultimate strength of 1400 MPa and Young's modulus of 200 GPa. 4. To limit the maximum radial fi...

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“…However, the chargeedischarge rate of coils without turn-to-turn insulation is considerably slower than that of completely insulated coils due to the absence of insulationconferred resistance [11e17]. Therefore, implementation of a partial insulation (PI) winding technique is a potential solution for the problem of the slow chargeedischarge rate experienced by NI coils [18]. Recently, we reported improvement of the chargeedischarge delay of NI coils through inclusion of a number of insulation layers in between selected turns of an NI coil [18,19].…”

Section: Introductionmentioning

confidence: 99%

Effect of partial insulation winding scheme on discharge characteristics of GdBCO coils

Yang

Choi

Kang

et al. 2015

Current Applied Physics

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Partial insulation of GdBCO single pancake coils for protection-free HTS power applications

Cited by 99 publications

References 11 publications

Status of the technology development of large scale HTS generators for wind turbine

Status of the technology development of large scale HTS generators for wind turbine

First-cut design of an all-superconducting 100-T direct current magnet

Effect of partial insulation winding scheme on discharge characteristics of GdBCO coils

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