### Abstract

Superconductors have been being applied to a variety of large-scale power applications, including magnets, electric machines, and fault current limiters, because they can enable a compact, lightweight and high efficiency design. In applications such as those mentioned above, superconducting coils are always a key component. For example, in a superconducting electric machine, the superconducting coils are used to generate the main flux density in the air gap, which is significantly important for the energy conversion. It is the performance of the superconducting coils that plays an essential role in determining the performance of the device. However, the performance of a superconducting coil is limited by its critical current, which is determined by temperature and the magnitude and orientation of the magnetic field inside the superconductors. Hence, in-depth investigations to estimate the critical current of the superconducting coils are necessary before manufacturing. Available transient simulation models to estimate the critical current are through the H- and T-A formulations of Maxwell's equations. Both methods consider the same current ramp-up process occurring in experiments. Besides these transient models, static simulations can also be used: a modified load-line method and the so-called P-model, which is based on the asymptotic limit of Faraday's equation when time approaches infinity. To find the best way to calculate the critical current, the four methods are used to estimate the critical current of a double pancake superconducting coils and results are compared with experiments. As a conclusion, T-A formulation, P-model, and the modified load-line methods are recommended for estimating the critical current of the superconducting coils.

Original language | English |
---|---|

Article number | 014001 |

Number of pages | 12 |

Journal | Superconductor Science and Technology |

Volume | 32 |

Issue number | 1 |

Early online date | 28 Nov 2018 |

DOIs | |

Publication status | Published - 1 Jan 2019 |

### Fingerprint

### Keywords

- 2D numerical model
- critical current
- N-value
- superconducting coil
- tape anisotropy

### Cite this

*Superconductor Science and Technology*,

*32*(1), [014001]. https://doi.org/10.1088/1361-6668/aae960

}

*Superconductor Science and Technology*, vol. 32, no. 1, 014001. https://doi.org/10.1088/1361-6668/aae960

**Comparison of 2D simulation models to estimate the critical current of a coated superconducting coil.** / Liu, Yingzhen; Ou, Jing; Grilli, Francesco; Schreiner, Fabian; Zermeno, Victor Manuel Rodriguez; Zhang, Min; Noe, Mathias.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Comparison of 2D simulation models to estimate the critical current of a coated superconducting coil

AU - Liu, Yingzhen

AU - Ou, Jing

AU - Grilli, Francesco

AU - Schreiner, Fabian

AU - Zermeno, Victor Manuel Rodriguez

AU - Zhang, Min

AU - Noe, Mathias

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Superconductors have been being applied to a variety of large-scale power applications, including magnets, electric machines, and fault current limiters, because they can enable a compact, lightweight and high efficiency design. In applications such as those mentioned above, superconducting coils are always a key component. For example, in a superconducting electric machine, the superconducting coils are used to generate the main flux density in the air gap, which is significantly important for the energy conversion. It is the performance of the superconducting coils that plays an essential role in determining the performance of the device. However, the performance of a superconducting coil is limited by its critical current, which is determined by temperature and the magnitude and orientation of the magnetic field inside the superconductors. Hence, in-depth investigations to estimate the critical current of the superconducting coils are necessary before manufacturing. Available transient simulation models to estimate the critical current are through the H- and T-A formulations of Maxwell's equations. Both methods consider the same current ramp-up process occurring in experiments. Besides these transient models, static simulations can also be used: a modified load-line method and the so-called P-model, which is based on the asymptotic limit of Faraday's equation when time approaches infinity. To find the best way to calculate the critical current, the four methods are used to estimate the critical current of a double pancake superconducting coils and results are compared with experiments. As a conclusion, T-A formulation, P-model, and the modified load-line methods are recommended for estimating the critical current of the superconducting coils.

AB - Superconductors have been being applied to a variety of large-scale power applications, including magnets, electric machines, and fault current limiters, because they can enable a compact, lightweight and high efficiency design. In applications such as those mentioned above, superconducting coils are always a key component. For example, in a superconducting electric machine, the superconducting coils are used to generate the main flux density in the air gap, which is significantly important for the energy conversion. It is the performance of the superconducting coils that plays an essential role in determining the performance of the device. However, the performance of a superconducting coil is limited by its critical current, which is determined by temperature and the magnitude and orientation of the magnetic field inside the superconductors. Hence, in-depth investigations to estimate the critical current of the superconducting coils are necessary before manufacturing. Available transient simulation models to estimate the critical current are through the H- and T-A formulations of Maxwell's equations. Both methods consider the same current ramp-up process occurring in experiments. Besides these transient models, static simulations can also be used: a modified load-line method and the so-called P-model, which is based on the asymptotic limit of Faraday's equation when time approaches infinity. To find the best way to calculate the critical current, the four methods are used to estimate the critical current of a double pancake superconducting coils and results are compared with experiments. As a conclusion, T-A formulation, P-model, and the modified load-line methods are recommended for estimating the critical current of the superconducting coils.

KW - 2D numerical model

KW - critical current

KW - N-value

KW - superconducting coil

KW - tape anisotropy

UR - http://www.scopus.com/inward/record.url?scp=85062445861&partnerID=8YFLogxK

UR - https://arxiv.org/abs/1807.10352

UR - https://publikationen.bibliothek.kit.edu/1000088737

U2 - 10.1088/1361-6668/aae960

DO - 10.1088/1361-6668/aae960

M3 - Article

VL - 32

JO - Superconductor Science and Technology

JF - Superconductor Science and Technology

SN - 0953-2048

IS - 1

M1 - 014001

ER -