Influence of AC external magnetic field perturbation on the guidance force of HTS bulk over a NdFeB guideway

Zhang, Longcai; Wang, Jiasu; Wang, Suyu; He, Qinglie

doi:10.1016/j.physc.2007.04.222

Cited by 16 publications

(9 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Generally, high-temperature superconductor (HTS) based magnetic Levitation (maglev) vehicle systems consist of HTS on a permanent magnet (PM) guideway [23][24][25]. In general, uniform magnetic field is considered for PM guideways but practically this is not the case; there are situations of magnetic field variations (e.g., cracks, magnetic contacts, and structural and magnetic defects) resulting in a variable magnetic field.…”

Section: Introductionmentioning

confidence: 99%

Effect of Background Magnetic Field on Type-II Superconductor under Oscillating Magnetic Field Simulated Using Ginzburg-Landau Model

Jafri

Zhao

Huang

et al. 2018

Advances in Condensed Matter Physics

View full text Add to dashboard Cite

Cubic superconducting sample was simulated using time-dependent Ginzburg-Landau model under oscillating magnetic field with and without additional background static magnetic field. Vortex dynamics including entrance and exit from the sample was simulated. Magnetization and carrier concentration densities of the sample were studied as a function of external magnetic field variations. Anomalies in carrier concentration density were observed at certain values of the magnetic field which were correlated with the entrance and exit processes of vortices. Area swept by superconductor magnetization with magnetic field was observed to have a hysteresis-like behavior where area representing energy dissipated per cycle. This energy accumulation was suggested to cause instability in superconductor over the number of cycles and may result in thermal quenching. Temporal distribution of energy components showed consistency with the pattern observed for carrier concentration and magnetization under oscillating magnetic field. Rapid phase changes with magnetic oscillations resulted in oscillations in energy components, and irregular peaks and ripples in superconducting energy represent the situation of exit and entry of vortices. While the rise in interaction energy with cycles is referred to vortex relaxation time in a cycle, this energy is expected to accumulate and take other forms (e.g., heat) and is predicted to cause thermal quenching. In the presence of background static magnetic field, this energy dissipation was calculated to increase significantly while superconductor is subjected to oscillating magnetic field.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of Background Magnetic Field on Type-II Superconductor under Oscillating Magnetic Field Simulated Using Ginzburg-Landau Model

Jafri

Zhao

Huang

et al. 2018

Advances in Condensed Matter Physics

View full text Add to dashboard Cite

show abstract

“…An onboard high-temperature superconductor (HTS) on a permanent magnetic (PM) guideway is the basic assembly of most HTS maglev vehicle systems [12][13][14]. It is assumed that the magnetic field under HTS is uniform longitudinally, but there are situations where magnetic field variation occurs, like between two adjacent PMs, PM cracks, etc; as a result, HTS experiences a variation in the magnetic field while moving on the PM guideway.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of vortex dynamics in type-II superconductors in oscillating magnetic field using time-dependent Ginzburg–Landau equations

Jafri

Zhao

et al. 2017

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Time-dependent Ginzburg-Landau equations were solved by the finite difference scheme for a superconducting sample in steady and oscillating magnetic fields for 3D geometry. The dynamic behaviour of penetrating and leaving magnetic vortices in superconductor with the oscillating magnetic field was simulated. Carrier concentration density and the average magnetization of the sample were studied as a function of the external oscillating magnetic field. Anomalies in carrier concentrations at certain magnetic field values were observed and discussed. It was also observed that the area swept by magnetization versus external magnetic field is magnetic oscillation frequency dependent, which increases with increasing frequencies. It was suggested that this effect may cause instability in the superconducting characteristics of the sample over a number of cycles. Calculated energy patterns showed consistency with vortex patterns in the steady magnetic field. Magnetic oscillations initiated oscillations in energy components, ripples in superconducting energy are subjected to the entrance and leaving of vortices, while instability observed in interaction energy is referred to vortex relaxation time.

show abstract

“…Prior studies on the levitation behavior via AC field perturbations [1], [2] cannot fully imitate the spatial varying applied field under vehicle running performance because it only produced the perturbation along one directional axis. However, with the developed HTS Maglev dynamic measurement system (SCML-03) [4] at the Applied Superconductivity Laboratory (ASCLab) of Southwest Jiaotong University, P. R. China, with a circular permanent magnet guideway (PMG) of 1.5 m in diameter, the vehicle's translational motion above a PMG can be effectively simulated with the circular PMG allowed to rotate freely underneath [5].…”

Section: Introductionmentioning

confidence: 99%

Levitation Force Transition of High-Tc Superconducting Bulks above a Spinning Permanent Magnetic Guideway

Liu¹,

Li²

2016

Proceedings of the 2016 Joint International Information Technology, Mechanical and Electronic Engineering

View full text Add to dashboard Cite

Abstract. In practical application of a High-Tc Superconducting (HTS) maglev vehicle, the onboard HTS bulks are inevitably exposed to a varying inhomogeneous field due to present processing and assembling technology of the permanent magnetic guideway (PMG). To explore the influence on the levitation forces of YBa 2 Cu 3 O 7-x bulk samples in such changing external magnetic field due to different traveling speeds, we experimentally investigated the general transition of said levitation force under such varying external field simulated by a spinning circular PMG. The force waves general attenuated caused by AC loss brought by magnetic field fluctuating. For further information on that levitation dynamic equilibrium, we study experimentally the wave detail and general transition of the dynamic levitation force under different steady velocities between 0 and 120 km/h. Ultimately the results indicated that the attenuation saturated rapidly in higher speed that would be of benefit to the HTS-PMG system in long-term operating.

show abstract

Influence of AC external magnetic field perturbation on the guidance force of HTS bulk over a NdFeB guideway

Cited by 16 publications

References 5 publications

Effect of Background Magnetic Field on Type-II Superconductor under Oscillating Magnetic Field Simulated Using Ginzburg-Landau Model

Effect of Background Magnetic Field on Type-II Superconductor under Oscillating Magnetic Field Simulated Using Ginzburg-Landau Model

Numerical simulation of vortex dynamics in type-II superconductors in oscillating magnetic field using time-dependent Ginzburg–Landau equations

Levitation Force Transition of High-Tc Superconducting Bulks above a Spinning Permanent Magnetic Guideway

Contact Info

Product

Resources

About