DC characterization and 3D modelling of a triangular, epoxy-impregnated high temperature superconducting coil

Di, Honggui; Ainslie, Mark; Rush, J. P.; Durrell, John; Zeng, Jin; Raine, MJ; Hampshire, D.P.

doi:10.1088/0953-2048/28/6/065011

Cited by 32 publications

(43 citation statements)

References 62 publications

(185 reference statements)

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“…2. This method of data input is simple and direct, and can significantly improve the computational speed of the model [38,39]. The 2D axisymmetric model assumes a homogeneous J c distribution around the abplane, neglecting any effects from any inhomogeneity of J c , e.g., [29,[41][42][43].…”

Section: Numerical Modelling 21 Modelling Frameworkmentioning

confidence: 99%

Flux jump-assisted pulsed field magnetisation of high-J_cbulk high-temperature superconductors

Ainslie

Zhou

Fujishiro

et al. 2016

Supercond. Sci. Technol.

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Investigating, predicting and optimising practical magnetization techniques for charging bulk superconductors is a crucial prerequisite to their use as high performance 'psuedo' permanent magnets. The leading technique for such magnetization is the pulsed field magnetization (PFM) technique, in which a large magnetic field is applied via an external magnetic field pulse of duration of the order of milliseconds. Recently "giant flux leaps" have been observed during charging by PFM: this effect greatly aids magnetization as flux jumps occur in the superconductor leading to magnetic flux suddenly intruding into the centre of the superconductor. This results in a large increase in the measured trapped field at the centre of the top surface of the bulk sample and full magnetization. Due to the complex nature of the magnetic flux dynamics during the PFM process simple analytical methods, such as those based on the Bean critical state model (CSM), are not applicable. Consequently, in order to successfully model this process, a multi-physical numerical model is required, including both electromagnetic and thermal considerations over short time scales. In this paper, we show that a standard numerical modelling technique, based on a 2D axisymmetric finiteelement model implementing the H-formulation, can model this behaviour. In order to reproduce the observed behaviour in our model all that is required is the insertion of a bulk sample of high critical current density, J c. We further explore the consequences of this observation by examining the applicability of the model to a range of previously reported experimental results. Our key conclusion is that the "giant flux leaps" reported by Weinstein et al. and others need no new physical explanation in terms of the behaviour of bulk superconductors: it is clear the "giant flux leap" or flux jump-assisted magnetisation of bulk superconductors will be a key enabling technology for practical applications.

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Section: Numerical Modelling 21 Modelling Frameworkmentioning

confidence: 99%

Flux jump-assisted pulsed field magnetisation of high-J_cbulk high-temperature superconductors

Ainslie

Zhou

Fujishiro

et al. 2016

Supercond. Sci. Technol.

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“…c norm IB  ), the critical current density is derived based on Equation (  into the simulation model, a two-variable interpolation method is used [35]. In this Since 2D cross section model of superconductor is used, where the end effect is neglected, current flows in the direction perpendicular to the cross section only.…”

Section: Experiments Setupmentioning

confidence: 99%

Vortex shaking study of REBCO tape with consideration of anisotropic characteristics

Liang

Zhang

et al. 2017

Supercond. Sci. Technol.

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The second generation high temperature superconductor, specifically REBCO, has become a new research focus in the development of high-field (>25T) magnets. Previous research shows that applying an AC field in plane with the circulating current will lead to demagnetization due to vortex shaking. To unveil the vortex shaking mechanism of REBCO stacks， this paper provides an in-depth study, both experimentally and numerically,. A new experiment was carried out to measure the demagnetization rate of REBCO stacks exposed to an in-plane AC magnetic field. Meanwhile, 2D finite element models, based on the E-J power law, are developed to simulate the vortex shaking effects. Qualitative agreement was obtained between the experiment results and the simulation results. Our results show that the in-plane magnetic field leads to a sudden decay of the trapped magnetic field in the first half shaking cycle, due to magnetic field dependence of the circulating current. Furthermore, the decline rate of demagnetization with the increase of tape number is due to the increase of trapped magnetic field in the stack. Further study concerning the frequency of the applied AC magnetic field shows that it has little impact on the demagnetization process. Our modeling tool and findings will provide useful guidance in the development of future shaking devices for REBCO magnets.

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“…Epoxy resins like Stycast are known to be used in cryogenic applications [19], for instance, as an encapsulating material for HTS coils to prevent movement of CC tapes and to ensure even distribution of loads [20][21][22][23]. Generally speaking, coefficient of thermal expansion (CTE) of epoxy resins is much larger than CTE of Hastelloy C276 ® , usually used as a substrate of CC tapes, and their thermal conductivity is very low.…”

Section: Introductionmentioning

confidence: 99%

Composite Heat Sink Material for Superconducting Tape in Fault Current Limiter Applications

et al. 2020

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We enhanced the performance of superconducting tapes during quenching by coating the tapes with various composites, with regards to the application of such coated systems in superconducting fault current limiters. In composition of the coating, we varied the type of epoxy matrix, the content of ceramic filler particles and the use of reinforcement in order to optimize the thermal and the mechanical stability of the coated tapes. By this way modified superconducting tapes were able to reduce the maximum temperature 170 °C of not modified superconducting tape to 55 °C during the quench with electric field up to 130 V m−1.

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DC characterization and 3D modelling of a triangular, epoxy-impregnated high temperature superconducting coil

Cited by 32 publications

References 62 publications

Flux jump-assisted pulsed field magnetisation of high-J_cbulk high-temperature superconductors

Flux jump-assisted pulsed field magnetisation of high-J_cbulk high-temperature superconductors

Vortex shaking study of REBCO tape with consideration of anisotropic characteristics

Composite Heat Sink Material for Superconducting Tape in Fault Current Limiter Applications

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DC characterization and 3D modelling of a triangular, epoxy-impregnated high temperature superconducting coil

Cited by 32 publications

References 62 publications

Flux jump-assisted pulsed field magnetisation of high-Jcbulk high-temperature superconductors

Flux jump-assisted pulsed field magnetisation of high-Jcbulk high-temperature superconductors

Vortex shaking study of REBCO tape with consideration of anisotropic characteristics

Composite Heat Sink Material for Superconducting Tape in Fault Current Limiter Applications

Contact Info

Product

Resources

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Flux jump-assisted pulsed field magnetisation of high-J_cbulk high-temperature superconductors

Flux jump-assisted pulsed field magnetisation of high-J_cbulk high-temperature superconductors