Superconducting magnets possess unique electromagnetic properties, making them applicable in fields such as nuclear magnetic resonance, maglev, and fusion. These applications generally involve diverse environments fea...Superconducting magnets possess unique electromagnetic properties, making them applicable in fields such as nuclear magnetic resonance, maglev, and fusion. These applications generally involve diverse environments featuring AC or DC conditions, where superconducting properties are influenced by various factors. Specifically, the most concerning properties in high temperature superconducting (HTS) magnets include critical current, AC loss, screening current effects, and so on. Finite element method is widely used in reliable numerical studies for these properties. Several popular models have been proposed and developed to get higher precision and less calculation time. However, constrained by computational resources, they still have challenges in supporting high-throughput analysis. In various studies on electromagnetic characteristics of magnets, a substantial amount of data is often required to facilitate the introduction of artificial intelligence (AI) methods or optimization approaches. This paper proposes an adaptive-extended J-model to compute superconducting properties, further enhancing the efficiency of electromagnetic study and also serving to generate dataset for AI methods. It reduces computation time to only 20%–30% of that of the existing fastest model while maintaining similar levels of accuracy. By using this method as a data-generative tool, the dataset of a series of HTS solenoids including 2000 turns is expeditiously obtained and employed to predict the screening current induced field. The predictive performance is reliable under the dataset calculation time of mere minutes. This study significantly shortens the time to realize big dataset demands, accelerating electromagnetic study of superconducting magnets in various scenarios.展开更多
No-insulation(NI)high-temperature superconducting(HTS)coil wound with parallel-stacked tapes emerges as a prospective choice for high-field fusion magnets owing to lower inductance and faster ramping rate.The parallel...No-insulation(NI)high-temperature superconducting(HTS)coil wound with parallel-stacked tapes emerges as a prospective choice for high-field fusion magnets owing to lower inductance and faster ramping rate.The parallel stacked-tape structure leads to new current redistribution among stacked tapes in each turn during local quenches,which also considerably changes the current redistribution behavior through inter-turn contacts.Therefore,quench behaviors of parallel-wound no-insulation(PWNI)coil should differ from its counterpart wound with single tape,which are still unknown.This study is to illustrate quench behaviors of PWNI HTS coils induced by local hot spot.A multi-physics model integrating an equivalent circuit network,a FEM heat transfer module,and a FEM T-A model is developed to analyze the electromagnetic and thermal characteristics of PWNI HTS coils during quench.Results show that the transport currents are mainly redistributed among parallel-stacked tapes through terminal resistances when a local hot spot happens on one tape,while being less dependent on turn-to-turn electrical contacts.It leads to a coupling current within PWNI coils that is not present in NI coils wound with single tape(single-wound no-insulation(SWNI)coil),resulting in a highly non-uniform transport current distribution among parallel-wound tapes.The reduced terminal joint resistances further enhance the coupling current,potentially leading to an extra overcurrent quench risk in PWNI coils.Moreover,the current redistribution between parallel-stacked tapes inhibits the turn-to-turn current redistribution in the PWNI coil,thus significantly reducing its magnetic field degradation under a high heat disturbance,which can be almost less than half of the SWNI counterpart in this study.These results offer important theoretical guidance to safety operation and robustness improvement of high-field HTS magnets wound by PWNI technique.展开更多
基金supported by National Natural Science Foundation of China under Grant No.52207026.
文摘Superconducting magnets possess unique electromagnetic properties, making them applicable in fields such as nuclear magnetic resonance, maglev, and fusion. These applications generally involve diverse environments featuring AC or DC conditions, where superconducting properties are influenced by various factors. Specifically, the most concerning properties in high temperature superconducting (HTS) magnets include critical current, AC loss, screening current effects, and so on. Finite element method is widely used in reliable numerical studies for these properties. Several popular models have been proposed and developed to get higher precision and less calculation time. However, constrained by computational resources, they still have challenges in supporting high-throughput analysis. In various studies on electromagnetic characteristics of magnets, a substantial amount of data is often required to facilitate the introduction of artificial intelligence (AI) methods or optimization approaches. This paper proposes an adaptive-extended J-model to compute superconducting properties, further enhancing the efficiency of electromagnetic study and also serving to generate dataset for AI methods. It reduces computation time to only 20%–30% of that of the existing fastest model while maintaining similar levels of accuracy. By using this method as a data-generative tool, the dataset of a series of HTS solenoids including 2000 turns is expeditiously obtained and employed to predict the screening current induced field. The predictive performance is reliable under the dataset calculation time of mere minutes. This study significantly shortens the time to realize big dataset demands, accelerating electromagnetic study of superconducting magnets in various scenarios.
基金sponsored by National Key R&D Program of China(No.2023YFE0118100)The work is also sponsored by National Natural Science Foundation of China(No.52207028)+1 种基金The work is also spon-sored by Shanghai Science&Technology Innovation Action Program(No.23511101800)The work is also sponsored by Natural Science Foundation of Chongqing(No.2022NSCQ-MSX1512).
文摘No-insulation(NI)high-temperature superconducting(HTS)coil wound with parallel-stacked tapes emerges as a prospective choice for high-field fusion magnets owing to lower inductance and faster ramping rate.The parallel stacked-tape structure leads to new current redistribution among stacked tapes in each turn during local quenches,which also considerably changes the current redistribution behavior through inter-turn contacts.Therefore,quench behaviors of parallel-wound no-insulation(PWNI)coil should differ from its counterpart wound with single tape,which are still unknown.This study is to illustrate quench behaviors of PWNI HTS coils induced by local hot spot.A multi-physics model integrating an equivalent circuit network,a FEM heat transfer module,and a FEM T-A model is developed to analyze the electromagnetic and thermal characteristics of PWNI HTS coils during quench.Results show that the transport currents are mainly redistributed among parallel-stacked tapes through terminal resistances when a local hot spot happens on one tape,while being less dependent on turn-to-turn electrical contacts.It leads to a coupling current within PWNI coils that is not present in NI coils wound with single tape(single-wound no-insulation(SWNI)coil),resulting in a highly non-uniform transport current distribution among parallel-wound tapes.The reduced terminal joint resistances further enhance the coupling current,potentially leading to an extra overcurrent quench risk in PWNI coils.Moreover,the current redistribution between parallel-stacked tapes inhibits the turn-to-turn current redistribution in the PWNI coil,thus significantly reducing its magnetic field degradation under a high heat disturbance,which can be almost less than half of the SWNI counterpart in this study.These results offer important theoretical guidance to safety operation and robustness improvement of high-field HTS magnets wound by PWNI technique.
