Numerical Evaluation of Screening Current-Induced Magnetic Field in No-Insulation REBCO Coil Systems
Numerical Evaluation of Screening Current-Induced Magnetic Field in No-Insulation REBCO Coil Systems
复制标题
非绝缘 REBCO 线圈系统中屏蔽电流感应磁场的数值评估
DOI：
10.1109/tasc.2021.3064540
复制
发表时间：
2021
影响因子：
1.8
通讯作者：
S.Noguchi
中科院分区：
文献类型：
--
作者：
S.Ueda;A.Ishiyama;H.Ueda;S.Noguchi
我们一直在开发一种无绝缘（NI） REBCO线圈，该线圈有望应用于医疗加速器和磁共振成像，作为一种既能实现高热稳定性又能实现高电流密度的技术。由于rebco涂层导体的形状平坦且比厚度和宽度大得多，通过改变垂直穿透胶带的磁通量，可以显著地诱导出屏蔽电流。对于绝缘（INS）线圈，这种屏蔽电流会产生不规则的磁场（屏蔽电流感应磁场（SCIF））。此外，在NI线圈中，由于电流沿线圈激励的径向流动，会发生激励延迟。因此，作为引起磁场不规则的原因，有必要同时考虑励磁延迟和SCIF的影响。在这项研究中，我们数值研究了NI线圈中的磁场。SCIF和激励延迟降低了NI线圈的磁精度。因此，我们提出了一种即使存在激励延迟也能提高磁场精度的激励波形。此外，我们验证了其有效性。
We have been developing a no-insulation (NI) REBCO coil which is expected to be applied to medical accelerators and magnetic resonance imaging as a technology that can achieve both high thermal stability and high current density. Due to the flat shape and much greater, than the thickness, width of a REBCO-coated conductor, the screening currents are remarkably induced by changing the magnetic flux that penetrates the tape vertically. For insulated (INS) coils, this screening current causes an irregular magnetic field (screening current-induced magnetic field (SCIF)). Also, in the NI coil, an excitation delay occurs because of the current flowing in the radial direction with coil excitation. Therefore, as the cause of irregular magnetic field, it is necessary to simultaneously consider the influence of both the excitation delay and SCIF. In this study, we numerically investigate the magnetic field in the NI coil. The SCIF and an excitation delay reduce magnetic accuracy in the NI coil. Thus, we propose an energization waveform that can improve the magnetic field accuracy even if there is an excitation delay. Besides, we verified its effectiveness.