Scaling law for voltage–current curve of a superconductor tape with a power-law dependence of electric field on a magnetic-field-dependent sheet current density

Li, Shuo; Chen, Du-Xing

doi:10.1016/j.physc.2017.05.004

Cited by 11 publications

(2 citation statements)

References 23 publications

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“…Actually, n value, as a good indicator of the E-I resistive t r a n s i t i o n , s h o w s t h a t a l a r g e r . Magnetization loss of superconductor when exposed to external magnetic field at By = 20 mT, THD5 = 10%, and varying n values n value indicates the improvement of Ic of the superconductor, which leads to slightly lower AC losses [32].…”

Section: Effect Of N-value and B-dependency Of Critical Current Dementioning

confidence: 99%

Magnetization Loss in HTS Coated Conductor Exposed to Harmonic External Magnetic Fields for Superconducting Rotating Machine Applications

et al. 2021

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Previous studies on magnetization AC loss of high temperature superconducting (HTS) coated conductors (CCs) taken into account the ideally sinusoidal external magnetic field, or non-sinusoidal by considering only the harmonics in phase with the fundamental component. However, realistically magnetic field often contains harmonics with different phase angles and amplitudes. In this work, magnetization AC loss in HTS CC was studied, considering the phase angle φ of each harmonic; assuming superconductor is subjected to external magnetic field which is distorted by the 3 rd and the 5 th harmonics. Phase angle of each harmonic was considered in the range of 0 to 2π and amplitude of fundamental magnetic field, was assumed as 10, 20, 50, and 100 mT. Different distortion level of magnetic field was considered too. It is concluded that phase angle of field harmonic has a significant effect on magnetization loss of HTS CCs. INDEX TERMS External magnetic field, Harmonic phase angle, HTS coated conductor, Magnetization AC loss. Date of publication xxxx 00, 0000, date of current version xxxx 00, 0000.

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Section: Effect Of N-value and B-dependency Of Critical Current Dementioning

confidence: 99%

Magnetization Loss in HTS Coated Conductor Exposed to Harmonic External Magnetic Fields for Superconducting Rotating Machine Applications

et al. 2021

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“…It has been previously reported that the measured I-V characteristics of HTS tapes are sensitive to the rate at which current is injected into the material [112][113][114][115] in both thin film and cylindrical wire geometries. In that work an analytic model has been presented in which the electric field in the edge regions can be several orders of magnitude larger than at the tape centre.…”

Section: Fe Modelling Of I Cs At Different Ramp Ratesmentioning

confidence: 99%

Modelling of Saturation Currents and Dynamic Resistance in High-Temperature-Superconductors

Brooks¹

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High temperature coated conductors are useful for their large Tc, Jc and Bc2values. They are manufactured in long lengths and are available from numerouscommercial distributors around the world. As a result, they have found use inmany applications that can utilise the large magnetic fields that these materialscan produce. In any complex circuit that incorporates superconducting components, it can bedesirable to include superconducting analogues of semiconducting power electronics,such as switches, and transistors. The ideal switch in a superconducting circuit haszero resistance when the switch is closed and infinite resistance when open. Onlysuperconductors can provide the zero resistance closed state. Thus it is the onset ofresistive phenomenon, the conditions under which a non zero resistance is inducedin a superconducting tape, stack, or loop, that are the subject of this thesis. The two phenomena that are examined are: geometric current saturation, and dynamicresistance. Both are investigated using existing finite element models employing the H-formulation and a power-law resistivity in the software COMSOL, accompaniedby experimental verification. Flux flow resistance arises when the transport current in a high temperature superconductor is larger than the critical current I c. This current produces asufficiently large Lorentz force such that there is continuous vortex motion through the superconductor. This results in an effective DC resistance. Today, the criticalcurrent is universally identified using an arbitrary voltage measurement criterion. In this thesis, it is demonstrated that current filling and eventual saturation acrossthe width of a HTS tape can be observed using magnetic field imaging near to the tape surface and correlated with changes in the measured I-V characteristics. Asimple model is presented to explain this behaviour which requires only that the material have a non-linear resistivity. The current filling behaviour is modelledusing numerical methods and validated against experimental data obtained from commercial wires. Finally, it is shown that the saturation determined using eithermagnetic field imaging or voltage measurements is sensitive to the rate of change of current. Dynamic resistance is a resistive phenomenon that occurs when an AC magnetic field interacts with a high temperature superconductor that is simultaneously carrying aDC transport current lower than the critical current. Dynamic resistance occurs when the AC field amplitude is larger than some sample dependent threshold. Comparison between numerical models and measured data demonstrate that field dependent Jc values are required to reproduce the experimentally observed transientvoltage waveforms. The finite element models were then used to analyse the transient current distributions inside of vertical stacks of parallel connected tapesand predict values for the threshold magnetic field. The threshold fields exhibit a transition from ’tape-like’ to ’slab-like’ behaviour as the stack aspect ratio varies. Finally, the effective resistance of a current carrying hollow superconducting strip exposed to an alternating perpendicular magnetic field is presented and analysedvia finite element modelling.

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Analyzing dynamic resistance in high-temperature superconducting tapes by combining finite element method with machine learning

Xiao,

Zeng,

Zhou

et al. 2024

J. Cent. South Univ.

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Scaling law for voltage–current curve of a superconductor tape with a power-law dependence of electric field on a magnetic-field-dependent sheet current density

Cited by 11 publications

References 23 publications

Magnetization Loss in HTS Coated Conductor Exposed to Harmonic External Magnetic Fields for Superconducting Rotating Machine Applications

Magnetization Loss in HTS Coated Conductor Exposed to Harmonic External Magnetic Fields for Superconducting Rotating Machine Applications

Modelling of Saturation Currents and Dynamic Resistance in High-Temperature-Superconductors

Analyzing dynamic resistance in high-temperature superconducting tapes by combining finite element method with machine learning

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