Thermal and Electromagnetic Performance Evaluation of REBCO Magnet With Solid Nitrogen Thermal Battery for Maglev Train

Mun, Jeongmin; Lee, Changyoung; Lee, Changhyung; Eom, Beomyong; Sim, Kideok; Kim, Seokho

doi:10.1109/tasc.2021.3060692

Cited by 20 publications

(8 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The significance of this applied field is as follows. In recent years, rotating and linear synchronous machines employing NI PCM coils have attracted increasing attention [4,14,33,[85][86][87][88]. In these applications, although the HTS rotor magnets are normally synchronous with the stator field and resemble a static field, they occasionally operate in dynamic conditions and encounter considerable non-synchronous time-varying fields, such as during the acceleration/deceleration and starting/breaking processes (which are frequent for wind turbines), electrical and mechanical vibrations, primary-coil-currentcontrol and out-of-step faults, and active short-circuits of the machine [89][90][91].…”

Section: Current Distribution Overviewsmentioning

confidence: 99%

“…The PCM operation provides the HTS magnet with advantages of: (a) less refrigerant consumption and higher thermal stability due to elimination of the heat leakage through current leads [1][2][3][4]; (b) robustness against unexpected power-off conditions [2,4]; (c) higher flexibility due to elimination of the cumbersome power source while running [4,5]; (d) possibility to generate a more stable DC magnetic field than the driven mode [2,6]. Therefore, PCM coils are desired in some energy storage systems [7,8], a few NMR/MRI projects [2,6,9,10] and most practically, the on-board magnets of maglev train systems [4,[11][12][13][14][15], which require high flexibility, safe off-power operation and efficient refrigeration. One of the major challenges concerning the PCM is that the persistent DC current circulating in the HTS coil would decay when exposed to AC fields due to the DC resistance generated in the superconductor, as illustrated by figure 1.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, our group adopted NI PCM REBCO coils to develop the first HTS electrodynamic suspension train system in China [14,40,41]. The Korea Railroad Research Institute is trying metalinsulation (MI) PCM REBCO coils as the on-board magnets for a vacuum tube maglev train project [3,4]. Under these conditions, the non-negligible AC fields from the stator windings demagnetize the PCM coils [42][43][44][45].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Study of the demagnetization behavior of no-insulation persistent-current mode HTS coils under external AC fields by 3D FEM simulation

Zhong,

Wu,

et al. 2024

Supercond. Sci. Technol.

View full text Add to dashboard Cite

The no-insulation (NI) winding technique is promising to be applied in the persistent-current mode (PCM) operation of high-temperature superconducting (HTS) coils to provide those advantages. To apply the NI PCM coil, its demagnetization behaviour (i.e., decay of persistent DC current) by external AC field, which occurs in maglev trains, electric machines, and other dynamic magnet systems, is essential to be understood. For this purpose, a 3D FEM model, capturing the full electromagnetic properties of NI HTS coils, is established. This work has studied three kinds of AC fields, observing the impact of turn-to-turn contact resistivity on demagnetization rates, which is attributed to current distribution modulations. Under transverse AC field, the lower contact resistivity attracts more transport current to flow in the radial pathway to bypass the ‘dynamic resistance’ generated in the superconductor, leading to slower demagnetization. Under axial AC field, the demagnetization rate exhibits a non-monotonic relation with the contact resistivity: (1) the initial decrease of contact resistivity leads to concentration of induced AC current on the outer turns, which accelerates the demagnetization; (2) the further decrease of contact resistivity makes the current smartly redistribute to avoid to flow through the loss-concentrated outer turns, thus slowing down the demagnetization. Under the rotating DC field, a hybrid of the transverse and axial fields, the impact of contact resistivity on the demagnetization rate exhibits combined characteristics of the transverse and axial components. Besides, quantitative prediction on the demagnetization rate of NI PCM coil under external AC field is instructive for practical designs and operations, which is tried by this 3D FEM model, and a comparison with experimental result is conducted.

show abstract

Section: Current Distribution Overviewsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Study of the demagnetization behavior of no-insulation persistent-current mode HTS coils under external AC fields by 3D FEM simulation

Zhong,

Wu,

et al. 2024

Supercond. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Each magnetic levitation method has its own advantages and disadvantages. Hyperloop, which shares superconducting electromagnets (SCMs) in the vehicle by EDS levitation and linear synchronous motor (LSM) propulsion, has the following advantages 17 – 20 . The strong magnetic field generated by SCMs generates a strong propulsion force to reach subsonic speeds, enables stable levitation at high-speed driving without control, and increases the levitation air gap, which can lower the infrastructure construction costs.…”

Section: Introductionmentioning

confidence: 99%

Equivalent inductance model for the design analysis of electrodynamic suspension coils for hyperloop

Lim

Lee

et al. 2021

Sci Rep

View full text Add to dashboard Cite

Hyperloop is a new concept of ground transportation. In Hyperloop, travelling occurs in near-vacuum tubes under 0.001 atm at a subsonic speed of up to 1200 km/h. During acceleration to and driving at a subsonic speed, magnetic levitation is employed. Thus far, various levitation technologies in existing high-speed maglev trains have been considered. Among those technologies, superconducting (SC) electrodynamic suspension (EDS) is a highly effective levitation system for Hyperloop owing to its advantages of a large levitation gap, levitation stability, and control being unnecessary. However, analyzing an EDS system requires the electromagnetic transient analysis of complex three-dimensional (3D) features, and its computational load generally limits the use of numerical methods, such as the 3D finite element method (FEM) or dynamic circuit theory. In this study, a novel model that can rapidly and accurately calculate the frequency-dependent equivalent inductance was developed. The developed model was then applied to design an EDS system using the decoupled resistance-inductance equations of levitation coils. Next, levitation coils of SC-EDS were designed and analyzed for use in Hyperloop. The obtained results were compared with the FEM results to validate the developed model. In addition, the model was experimentally validated by measuring currents induced by moving pods.

show abstract

“…Each magnetic levitation method has advantages and disadvantages. However, there are several advantages for Hyperloop that shares superconducting electromagnets (SCMs) in the vehicle by EDS levitation and linear synchronous motor (LSM) propulsion [17][18][19][20]. The strong magnetic field generated by SCMs generates a strong propulsion force to reach subsonic speeds, enables stable levitation in high-speed driving without control, and increases the levitation air gap, which can lower the cost of infrastructure construction.…”

Section: Introductionmentioning

confidence: 99%

Equivalent Inductance Model for the Design Analysis of Electrodynamic Suspension Coils for the Hyperloop

Lim

Lee

et al. 2021

Preprint

View full text Add to dashboard Cite

Hyperloop allows for improved transportation efficiency at higher speeds and a lower power consumption. Various magnetic levitation technologies in existing high-speed maglev trains are being considered to overcome speed limitations for the development of Hyperloop, which are driven inside vacuum tubes at 1,200 km/h; and superconducting (SC) electrodynamic suspension (EDS) can provide numerous advantages to Hyperloop. such as enabling stable levitation in high-speed driving without control, and increasing the levitation air gap. However, the analysis of the EDS system requires the electromagnetic transient analysis of complex three-dimensional (3D) features, and its computational load generally limits the use of numerical methods, such as the 3D finite element method (FEM) or dynamic circuit theory; This paper presents a novel model that can rapidly and accurately calculate the frequency-dependent equivalent inductance; and it can model the EDS system with the decoupled resistance-inductance (RL) equations of levitation coils. As a design example, the levitation coils of the SC-EDS were designed and analyzed for the Hyperloop, and the results were compared with those of the FEM results to validate the model. In addition, the model was experimentally validated by measuring currents induced by moving pods.

show abstract

Thermal and Electromagnetic Performance Evaluation of REBCO Magnet With Solid Nitrogen Thermal Battery for Maglev Train

Cited by 20 publications

References 30 publications

Study of the demagnetization behavior of no-insulation persistent-current mode HTS coils under external AC fields by 3D FEM simulation

Study of the demagnetization behavior of no-insulation persistent-current mode HTS coils under external AC fields by 3D FEM simulation

Equivalent inductance model for the design analysis of electrodynamic suspension coils for hyperloop

Equivalent Inductance Model for the Design Analysis of Electrodynamic Suspension Coils for the Hyperloop

Contact Info

Product

Resources

About