Role of asymmetric critical current on magnetization loss characteristics of (RE)Ba2Cu3O7−<i>d</i> coated conductors at various temperatures

Sun, Yu; Fang, Jin; Pantoja, A. E.; Badcock, Rodney A.; Long, N.J.; Jiang, Zhenan

doi:10.1063/5.0061937

Cited by 10 publications

(5 citation statements)

References 38 publications

(70 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is because the applied magnetic field is less than the effective penetration field (B e,p ) of the DPC. As discussed in the previous figure 8(b), B e,p of the DPC is around 125 mT at 77 K, which should be much greater at other low temperatures because B e,p is proportional to the critical current of the coil [25,35]. In addition, the Γ values decrease with decreasing temperature, which is attributed to the temperature-dependent critical current characteristics.…”

Section: Magnetization Loss In the Dpc At Various Temperaturesmentioning

confidence: 59%

Dynamic resistance and total loss in small REBCO pancake and racetrack coils carrying DC currents under an AC magnetic field

Sun

You²,

Badcock³

et al. 2023

Supercond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

In many high-temperature superconducting (HTS) applications, REBCO coils carry DC currents under AC magnetic fields,such as the field winding of rotating machines, linear synchronous motors and the electro-dynamic suspension system of maglev. In such operating conditions, REBCO coils generate AC loss—total loss which includes the magnetization loss due to the shielding currents, and the dynamic loss arising from dynamic resistance caused by the interaction of DC currents and AC magnetic fields. In this work, dynamic resistance and total loss in a small double pancake coil (DPC) and a small double racetrack coil (DRC) are investigated via experiments in the temperature range between 77 K and 65 K. The DC currents are varied from zero to 70% of the self-field critical currents of the REBCO coils, with AC magnetic fields up to 100 mT. The experimental results in the DPC are well supported by the finite element simulation results using 3D T-A formulation . Our results show the critical current of the DRC is approximately 2% − 5% higher than that of the DPC in the temperature range. For given experimental conditions, the magnetization loss in both coils is much greater than the dynamic loss. The dynamic loss and magnetization loss in the DRC are greater than those in the DPC, which we attribute to the large perpendicular magnetic field component in the straight sections of the DRC.

show abstract

Section: Magnetization Loss In the Dpc At Various Temperaturesmentioning

confidence: 59%

Dynamic resistance and total loss in small REBCO pancake and racetrack coils carrying DC currents under an AC magnetic field

Sun

You²,

Badcock³

et al. 2023

Supercond. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…This observation can be explained using the BI equation [26]. According to the equation, the magnetization loss is proportional to Bm 4 when Bm is much smaller than the effective magnetic field (Bp), and proportional to Bm when Bm is much greater than Bp [31]. In current work, Bp for the 40 mm conductor is 37.5 mT as marked in Fig.…”

Section: A Magnetization Lossmentioning

confidence: 85%

Numerical Simulations on AC Loss of the REBCO Tape Under Rotating Magnetic Field

Wang,

Fang,

Sogabe

et al. 2023

IEEE Access

Self Cite

View full text Add to dashboard Cite

REBCO coated conductors are exposed to rotating magnetic fields in various high-temperature superconducting (HTS) applications, such as HTS rotating machines and flux pumps. AC loss will be generated in the conductors when they carry AC current under rotating magnetic fields. We define AC loss in the coated conductors with and without current as total AC loss and magnetization loss, respectively. In this work, total AC loss and magnetization loss, in a REBCO tape under rotating magnetic fields and a perpendicular AC standing wave magnetic field are numerically investigated. We employ a 2D finite element method (FEM) based on the T-A formulation, where T and A, are the current and magnetic vector potentials, respectively. In the simulations, the external magnetic field amplitude (Bm) is up to 500 mT and the reduced AC current (i = It / Ic0) varies from 0.1 to 0.9, where the It and Ic0 are the amplitude of the transport current and self-field critical current of the conductor, respectively. Two different types of rotating fields are considered: one is a uniform field with equal amplitudes and phases at each position, and the other being a non-uniform field created by a rotating Halbach array. Different tape widths ranging from 4 mm to 40 mm are considered. Interestingly, the simulation results show substantially higher magnetization loss in the perpendicular standing wave compared to the rotating magnetic fields when Bm is over 100 mT. We attribute the result to the fact that the magnetization loss is propotional to Jc of the conductor at magnetic field amplitudes much greater than the effective penetration magnetic field. Evidently, the instantaneous loss curves of the SW model and RMF-Uniform model at 200 mT exhibited close similarity with evolving Jc values of the two models. Furthermore, when Bm is lower than the effective penetrated field, we observe a pronounced disparity in magnetization loss of the wider tape between uniform and non-uniform rotating fields. This highlights the importance of considering the effects of non-uniform field distribution, particularly at lower magnetic field. We further show that total AC loss under the perpendicular standing wave magnetic field remains greater than that under rotating magnetic fields when Bm > 100 mT and i < 0.5.INDEX TERMS REBCO coated conductors, rotating magnetic field, magnetization loss, total AC loss, finite element method (FEM).

show abstract

“…11 shows the distribution of the normalized current density J/Jc in C1 without/with pole shoes at 20 K. Similar to the results at 65 K, the areas of full magnetic penetration or |J/Jc| > 1 regions are reduced in the motor design with pole shoes. Furthermore, the magnitude of the AC loss at 20 K is much lower than that at 65 K. This can be explained by the increase of the effective penetration field in the HTS windings due to the increase of Ic at 20 K [11], [28], [29] However, it should be noted that cooling penalty becomes greater at lower operating temperatures. At 20 K, the cooling penalty increases to approximately 147 [30].…”

Section: 𝑱 = ∇ × 𝑻mentioning

confidence: 99%

Numerical Simulation of AC Loss in the Armature Windings of Two 50 Kw-Class All-HTS Motors With Different Pole Shapes

You

Kalsi

Ainslie

et al. 2022

IEEE Trans. Appl. Supercond.

Self Cite

View full text Add to dashboard Cite

Achieving low AC-loss armature windings is a key challenge to enable all-HTS motors. Large AC-loss is induced in the HTS armature windings through interaction with the rotating magnetic field generated by the rotor. To reduce the AC loss in the armature windings, it is important to minimize the impact of the rotating magnetic field, especially the component perpendicular to the broad face of REBCO conductors. This work presents two different 1500 rpm, 50 kW all-HTS motor designs with different iron pole shapes: one with pole shoes on the iron core for diverting the magnetic flux around the coil windings, and one without pole shoes. REBCO coated conductors are considered for both the armature and field windings and 2D finite-element models of both designs are built using the T-A formulation and moving meshes. System-wise analysis of the motor in terms of weight and efficiency is discussed based on the simulated AC loss results. The simulation results show that, at 65 K, flux diverting pole shoes provide a 51% AC loss reduction in the HTS armature windings, without weight penalty or motor power rating reduction. Furthermore, simulation results at 20 K show that the AC loss decreases with decreasing operating temperature due to a decrease in the penetrated field in the HTS windings, which reduces the magnetization loss component.

show abstract

Role of asymmetric critical current on magnetization loss characteristics of (RE)Ba2Cu3O7−d coated conductors at various temperatures

Abstract: Modeling current-voltage characteristics of DC reactive magnetron discharges and its application to superconducting NbTiN film deposition

Cited by 10 publications

References 38 publications

Dynamic resistance and total loss in small REBCO pancake and racetrack coils carrying DC currents under an AC magnetic field

Dynamic resistance and total loss in small REBCO pancake and racetrack coils carrying DC currents under an AC magnetic field

Numerical Simulations on AC Loss of the REBCO Tape Under Rotating Magnetic Field

Numerical Simulation of AC Loss in the Armature Windings of Two 50 Kw-Class All-HTS Motors With Different Pole Shapes

Contact Info

Product

Resources

About