Strong Magnetic Field Dependence of Micro-YBCO Superconductor Levitated Above Halbach Guideway

Liu, Xiaoning; Ke, Zhihao; Cheng, Yanxing; Liu, Yanzhi; Deng, Zigang

doi:10.1109/tim.2022.3216076

Cited by 10 publications

(9 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…mode B and C) and reflects at lower (mode B) or side surface (mode C). With reference to the experimental findings presented in [20], under comparable testing conditions, an induced current mainly flowing within the a-b planes of a 2 mm high and 2 mm wide bulk generates a levitation force that exceeds that generated by the current along the c-axis by 100%, whereas this discrepancy increases up to 30 times if the bulk is replaced with a stack. The observed phenomena of trapped field and levitation force are mutually indicative of the stack's behavior akin to an equivalent bulk with higher J c anisotropy property as illustrated in figure 6.…”

Section: Equivalent Anisotropy Of Stackmentioning

confidence: 66%

Levitation force approximation of YBCO hybrid superconductors using critical-state theory and partitioning method

Liu

Zheng

et al. 2023

Supercond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Introducing the second-generation coated conductor tapes (2G tapes) can enhance the performance of YBCO bulk superconductors (SCs) in terms of force, damping, and shape diversity. In this study, we investigate a hybrid SC that utilizes 2G tapes wrapped around the pivotal bulk component to achieve performance improvements. We also present a straightforward method, based on critical-state theory, to approximate the levitation force of this hybrid SC. This method characterizes the stack of tapes as an equivalent bulk with higher anisotropy and applies a fitting Kim model as an integrated expression of Jc(H) and Jc anisotropy. The partitioning method divides the SC into several isolated elements where the external field is approximately uniform within each sub-volume. Comparisons of calculated results with experiments indicate that this method can predict levitation properties with reasonable accuracy in just a few seconds. Furthermore, we propose two geometries of hybrid SC, namely, width-hybrid, and height-hybrid SC, for practical applications. Among them, the width-hybrid form exhibits higher eﬀiciency in levitation. Our findings highlight the importance of applying the coated conductor stack when the magnetic field orientation is perpendicular to the a-b planes.

show abstract

Section: Equivalent Anisotropy Of Stackmentioning

confidence: 66%

Levitation force approximation of YBCO hybrid superconductors using critical-state theory and partitioning method

Liu

Zheng

et al. 2023

Supercond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…This model takes the anisotropic influence of the field orientation into account. More details about this simulation could be seen in [13] J…”

Section: Effect Of Wavelength At Near Zero Heightmentioning

confidence: 99%

“…This approximation utilized a partitioning method that divided the SC into several isolated elements where the external field was approximately uniform within each subvolume (more detailed descriptions can be seen in [26,27]). Within each subvolume, the induced current was calculated based on the critical-state theory and the assumption of a uniform magnetic field [13]. Furthermore, during the downward movement of the SC in a zero-field cooling process, its magnetization, denoted as M, can be expressed as equations ( 7)- (9).…”

Section: Effect Of Wavelength At Near Zero Heightmentioning

confidence: 99%

“…Researchers have also carefully optimized the thickness and width of SCs and PMGs [8,9]. In addition, several measures such as lowering temperature [10], increasing field-cooling height [11], aligning the seeded surface of YBCO with the PMG [12], and arranging the c-axis of SCs parallel to external field [13] can all enhance levitation force. These efforts have led to impressive results, boosting the levitation performance of SC-PMG levitation systems by several tens of times, currently achieving over 1 ton per meter [14].…”

Section: Introductionmentioning

confidence: 99%

“…The γ affects the field intensity and gradient on the PMG surface. Both the magnetic field intensity and gradient determine the levitation performance [13,22].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Enhancing levitation force of superconductors through wavelength optimization in Halbach permanent magnet arrays

Liu,

Si,

et al. 2024

Supercond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Optimizing the wavelength ($\gamma$) of the Halbach array permanent magnet guideway (PMG) in superconducting maglev systems can improve levitation performance without consuming additional materials. The value of $\gamma$ impacts the external field intensity $\boldsymbol{H}_{\mathrm{e}}$ and gradient $\nabla \boldsymbol{H}_{\mathrm{e}}$ generated by the PMG. The total amount of magnetic field energy is fixed, and the $\gamma$ essentially regulates the distribution of this energy. Reducing $\gamma$ concentrates more magnetic field on the PMG surface, resulting in larger force and stiffness when the levitation height approaches zero. To validate this conclusion, experiments, approximate calculations and numerical simulations have been in all employed. However, excessive reducing $\gamma$ at higher heights is not ideal as it tends to distribute most of the field energy below the desired height. The approximate method in this paper indicates that the levitation force is positively correlated with $(\frac{\boldsymbol{H}_{\mathrm{e}}^{2}}{2H_{\mathrm{p}}}-\boldsymbol{H}_{\mathrm{e}})\nabla \boldsymbol{H}_{\mathrm{e}}$. Therefore, the objective is to determine the optimal $\gamma$ that maximizes this index. Optimal values for $\gamma$ at different heights have been identified, offering guidance for PMG design. Additionally, applying these findings to two existing PMGs results in 18\% and 8.6\% augmentation in levitation force respectively. Furthermore, a fully optimized PMG design has the potential to achieve a levitation force of nearly 10 kN/m, while keeping the cross-sectional areas of the PMG and SC restricted to 4450 mm$^2$ and 2500 mm$^2$, respectively.

show abstract

Simultaneous vibration suppression and energy harvesting system design via electromagnetic shunt damper for high temperature superconducting pinning maglev

Ke,

Deng,

Ren

et al. 2024

Mechanical Systems and Signal Processing

View full text Add to dashboard Cite

Strong Magnetic Field Dependence of Micro-YBCO Superconductor Levitated Above Halbach Guideway

Cited by 10 publications

References 38 publications

Levitation force approximation of YBCO hybrid superconductors using critical-state theory and partitioning method

Levitation force approximation of YBCO hybrid superconductors using critical-state theory and partitioning method

Enhancing levitation force of superconductors through wavelength optimization in Halbach permanent magnet arrays

Simultaneous vibration suppression and energy harvesting system design via electromagnetic shunt damper for high temperature superconducting pinning maglev

Contact Info

Product

Resources

About