Numerical calculations of the total ac loss of Cu-stabilized YBa2Cu3O7−δ coated conductor with a ferromagnetic substrate

We present the results of finite-element modeling of a YBCO thin-film superconductor deposited on a nonmagnetic substrate and on a weakly ferromagnetic substrate. The model was implemented using commercial software to calculate the ac loss in the presence of a sinusoidal external magnetic field applied perpendicular to the surface of the superconducting tape. A strategy is demonstrated to overcome the difficulties in the finite-element method due to the high aspect ratio of the YBCO film by using the computed values of ac loss for thicker samples to extrapolate the results to the actual physical thickness of the superconductor (∼1 μm). The effect of the width of the weekly ferromagnetic substrate upon the ac loss of the superconductor film has also been studied.

Section: Weakly Ferromagnetic Substratesupporting

confidence: 54%

Numerical Computation of AC Losses and Flux Profiles in High-Aspect-Ratio Superconducting Strips in Perpendicular AC Magnetic Field

Thakur

Staines

Lakshmi

et al. 2009

“…Similar to the measurements conducted by Duckworth et al [14], [15], the results also show that the contribution of ferromagnetic loss is significant for peak current ratio below 0.4. The detailed studies on temperature and frequency dependence of ac transport losses in YBCO tape and a comparison with the loss behavior of BSCCO tape were published previously [16], [17].…”

Section: Resultsmentioning

confidence: 99%

Quench Behavior of YBa$_{2}$Cu$_{3}$O$_{7}$ Coated Conductor With AC Transport Current

Zhang

Knoll

Nguyen

et al. 2007

Self Cite

Alternating current (ac) loss and quench behavior measurements were performed on a YBa 2 Cu 3 O x coated conductor at 45 K. The minimum quench energies (MQEs) and the quench propagation velocities were measured as a function of transport current and frequency. AC losses were measured at the corresponding temperature and frequencies to quantify the internal thermal load during ac quench measurements. It was found that the direct current (dc) and ac quench behavior are similar, but that the MQE for dc experiments is higher than the corresponding ac cases. This difference is not seen in the normal zone propagation velocity data, indicating that the difference in MQE is minimal if the ac losses are included in the energy calculation. The ac experiments show that the MQE and propagation velocity varies weakly with frequency.Index Terms-Alternating current (ac) quench, AC losses, minimum quench energy (MQE), normal zone propagation velocity, YBa 2 Cu 3 O 7 tape.

“…Thus, the eddy current loss at low temperatures is considerably smaller. Mathematically, both analytical [25] and numerical [26] models have shown that eddy current loss in metal layers (e.g., stabilizers) assembled in a thin strip superconductor strongly depends on the normalized field , where is a characteristic field determined from and the width, 2 , of the thin strip tape, . At low temperature, high causes high or small .…”

Section: Magnetization Ac Loss At Variable Temperaturesmentioning

confidence: 99%

“…In the simulation, the sample superconducting properties are assumed to follow the power-law characteristics determined by fitting the experimental current-voltage ( -) curve. The detailed mathematical formulation and calculation procedure of the numerical model were reported explicitly in [26]. As seen in Figs.…”

Section: Total Ac Loss At Variable Temperaturementioning

confidence: 99%

Temperature Dependence of Total AC Loss in High-Temperature Superconducting Tapes

Nguyen

Sastry

Knoll

et al. 2009

Self Cite

A versatile experimental facility was designed and set up to measure transport ac losses, magnetization ac losses, and total ac losses in high-temperature superconductors at variable temperatures. Several sets of measurements were carried out in the temperature range of 35 K to 100 K. Sample temperature during the measurements could be controlled within 0.5 K of set temperature. Temperature dependence of transport losses reflects variation of critical current density of the tapes with temperature. Temperature dependence of magnetization losses exhibits an interesting behavior with a peak, whose position shifts to lower temperatures as the magnetic field is increased. Experimental data of ac losses at various temperatures are compared with those calculated using numerical methods. Generally, the simulated results reproduce well the experimental data.