Simulation of Dynamic Resistance and Total Loss of HTS CORC Cables

Different electromagnetic formulations were proposed and implemented in finite element (FE) software to model high-temperature superconductors-coated conductors (HTS-CCs) and HTS tape topologies. However, their modelling can be notably demanding in computational resources, particularly computation time. Mixed formulations such as H − ϕ , T − A, and T − ϕ were proposed and used, proving to be considerably faster than conventional ones, although these formulations present different performances and characteristics depending on the modelled conditions and geometry. This paper reviews the electromagnetic formulations proposed in the literature for FE simulation of HTS-coated conductors and HTS tape topologies. Implementation aspects, which are lacking in the literature, are presented, especially for T − A and T − ϕ formulations developed for most relevant tape topologies, for example, HTS CC stacked (CCS) tape and HTS twisted tapes. Simulation results are analysed, alongside the consequent conclusions regarding the accuracy, as well as advantages and limitations of each formulation, all made taking into account each tape geometry and its operating conditions. Their implementation review will be straightforward in the case of H − formulation and A − formulation. In advance, the T − A formulation is shown to be the most efficient FE formulation for HTS-CC topologies, being, among the studied, the most efficient computational resource. Moreover, its inherent approximation of the HTS tape as a thin sheet has delivered accurate results, specifically regarding current density distributions in the HTS layer and AC losses when compared with the H − formulation. Correspondingly, FE multiphysics simulations are shown for three HTS-CC topologies: a single HTS tape, an HTS CCS tape, and an HTS twisted-stacked tape cable.

Section: Mixed Current Vector Potential-magnetic Vector Potential (T ...mentioning

confidence: 99%

Finite-element recipes for HTS-coated conductors and HTS tape topologies

Carvalho,

Ferreira da Silva,

Fernandes

et al. 2023

“…Terzioglu et al [31] respectively analyzed the AC loss characteristics of a single-layer CORC cable and a two-layer CORC cable and found that the transport AC loss of a single-layer CORC cable mainly comes from the eddy current loss generated by the axial magnetic field. Qiao et al [32] studied the dynamic resistance of single-layer and two-layer CORC cables. Wang et al [33] studied the magnetization loss of single-layer, two-layer and three-layer CORC cables, and concluded that the tape striation can significantly reduce the magnetization loss of CORC cables.…”

Section: Introductionmentioning

confidence: 99%

Numerical study on the electromagnetic characteristics of multi-layer CORC cables

Li,

Yang,

et al. 2024

Due to the high isotropy and low AC losses, the multi-layer conductor on Round Core (CORC) cable is a good candidate for high field magnets, such as central solenoid magnets in fusion. Considering the difficulty in experimental measurement, numerical model is an effective way to illustrate the electromagnetic characteristics of the multi-layer CORC cable and provide further insights into its working performance. In this work, A 3D finite element model based on H formulation is proposed to simulate a CORC cable with as many as 18 layers considering electromagnetic coupling. The validity of the model has been verified by experimental results. Based on the proposed model, the DC transport current distribution characteristics and charge-discharge loss characteristics of multi-layer CORC cables wound in the same and opposite winding directions are investigated respectively. This work can provide an important reference for the design of multi-layer CORC cables for high-current or high-field application.

“…There are extensive reports on the dynamic resistance and voltage response when REBCO CCs carry DC currents under AC magnetic fields, regarding the dependence on the amplitude and frequency of AC magnetic fields [25][26][27][28][29][30][31][32][33][34][35][36], operating temperatures [27,30,35,37], DC currents [25-30, 35, 38, 39] and waveforms of AC magnetic fields [39]. Several reports also present research on the influence of DC magnetic fields on the dynamic resistance and voltage of the CCs [22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Dynamic resistance and voltage response of a REBCO bifilar stack under perpendicular DC-biased AC magnetic fields

Sun

Geng

Badcock

et al. 2023

Self Cite

Dynamic resistance of REBCO coated conductors (CCs) is a key parameter in many high-temperature superconductor applications where CCs carry DC currents exposed to AC and DC magnetic fields, such as field-triggered persistent current switches, flux pumps, and fault current limiters. In this work, dynamic resistance and dynamic voltage has been studied via experiments and FEM simulations in a REBCO bifilar stack at 77 K under combined AC and DC magnetic fields with different magnitudes, frequencies, and waveforms. Our results show some distinct features of dynamic resistance and voltage from those under pure AC magnetic fields. With increasing DC magnetic fields, dynamic resistance exhibits an obvious linearity with applied AC magnetic fields, and becomes less dependent on the AC field frequency. The fundamental frequency of the dynamic voltage under DC magnetic fields becomes the same with that of the applied AC fields, which completely differs from the pure AC field case where the fundamental frequency doubles. For the first time, instantaneous threshold field (Bth) values are obtained from the dynamic voltage, which are substantically different in the field-increasing and field-decreasing process. These key differences are attributed to the dominant role of DC magnetic fields in determining the critical current of the superconductor, which significantly dwarfs the influence of AC fields. These new discoveries may help researchers better understand the electromagnetism of the superconductor and be useful for relevant applications.