FEM Calculation of Magnetization Process in a Multi-Filamentary Superconductor

Wake, M.; Yamada, R.

doi:10.1109/tasc.2007.899363

Cited by 3 publications

(3 citation statements)

References 10 publications

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“…8. Even though the copper model is based on a circle-shape, a square simulation model of the copper coil is selected for fast adaptive mesh refinement of the FEM simulation analysis [34]. Note that if the copper area is the same for the real and simulation models, then the copper loss is also the same for both cases, as described in Fig.…”

Section: /Jωmentioning

confidence: 99%

Optimal Number of Turns Design of the IPT Coils for Laptop Wireless Charging

et al. 2021

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The coil design of the inductive power transfer (IPT) for a transmitter (Tx) and receiver (Rx) is crucial to determine the performance of the IPT. Considering core loss and copper loss of the Tx and Rx coils, which are major loss terms of the whole IPT system, determination of the winding turns for the Tx and Rx coils becomes a key factor for maximum power transfer design of the IPT coils. In this paper, an optimal turns design of IPT coils for laptop wireless charging applications with a maximum power transfer efficiency is proposed. Under a specific design requirement of IPT, optimal turns of the Tx and Rx coils N1,op and N2,op can be determined by the proposed IPT coil design procedure with a finite-element-method (FEM) based simulation analysis. From the results of the coil design by the proposed IPT coil design methodology, N1,op and N2,op for maximum power efficiency, and input DC voltage Vdc for the target load power can be found by the proposed coil design procedure. The 40W prototypes of the two symmetry and asymmetry IPT coils for laptop wireless charging were fabricated, and verified by simulation and experiments. To separately verify the core and copper loss of the IPT coils, a resistance model and Steinmetz equation-based methods were comparatively evaluated, and it was found that they matched well at a core temperature condition of below 40 o C. The results showed that the total weight and the thickness of the Tx and Rx coils as well as the maximum power efficiencies of 95.1% and 96.8% for the symmetry and asymmetry cases were obtained by the proposed IPT coil design procedure, which becomes a practical solution for the laptop wireless charging coil design. INDEX TERMS Wireless power transfer (WPT), inductive power transfer (IPT), coil design, optimal turns design, laptop wireless charging, maximum power transfer efficiency.

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Section: /Jωmentioning

confidence: 99%

Optimal Number of Turns Design of the IPT Coils for Laptop Wireless Charging

et al. 2021

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“…We have been successful in making a computer simulation on magnetization curves using ANSYS [8], [9].…”

Section: Computer Simulation Of Magnetizationmentioning

confidence: 99%

“…We have demonstrated the feasibility of this mechanism using a 2D ANSYS model [9]. However, the combined behavior of the shielding current of Nb 3 Al filaments and the magnetization of the whole strand needs to be modeled by a 3-D finite element program with total multi-physics features, including the thermal effect.…”

Section: B Consideration For Simulation Of Anomalymentioning

confidence: 99%

Magnetization, Low Field Instability and Quench of RHQT ${\rm Nb}_{3}{\rm Al}$ Strands

Yamada

Wake

Kikuchi

et al. 2009

IEEE Trans. Appl. Supercond.

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Abstract-Since 2005, we made and tested three RHQT Nb 3 Al strands, one with Nb matrix and two with Ta matrix, which are fully stabilized with Cu electroplating. We observed anomalously large magnetization curves extending beyond 1 to 1.5 Tesla with the F1 Nb matrix strand at 4.2 K, when we measured its magnetization with a balanced coil magnetometer. This problem was eliminated with the Ta matrix strands operating at 4.2 K. But with these strands a similar but smaller anomalous magnetization was observed at 1.9 K. We studied these phenomena with FEM. With the F1 Nb matrix strand, it is explained that at low external field, inter-filamentary coupling currents in the outer layers of sub-elements create a shielding effect. It reduces the inside field, keeps the inside Nb matrix superconductive, and stands against a higher outside field beyond the Hc of Nb. At an even higher external field, the superconductivity of the whole Nb matrix collapses and releases a large amount of energy, which may cause a big quench. Depending on the size of the energy in the strand or the cable, a magnet could quench, causing the low field instability. Some attempt to analyze the anomaly with FEM is presented.

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