Finite element simulation and structure optimization of HTS solenoid
Finite element simulation and structure optimization of HTS solenoid
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DOI：
10.3389/fmats.2022.1109896
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发表时间：
2022-12-15
影响因子：
3.2
通讯作者：
Zhou, Kunpeng
中科院分区：
文献类型：
--
作者：
Cong, Menglong;Zhang, Shanshan;Zhou, Kunpeng
当高温超导（HTS）线圈中流过的电流超过临界值时，构成线圈的材料就会失效，产生大量的热量，甚至会引发严重的事故。针对上述安全问题，以三种不同结构的螺线管磁体为对象，采用有限元法对其电磁性能进行仿真研究。以磁场强度H作为物理场控制方程的因变量。借助所用仿真软件的偏微分方程（PDE）接口，可以方便地构造控制方程。将多匝带状导体绕制的扁平线圈抽象为具有相同截面积的块状导体。这种等效替换的主要思想是在不影响其电磁行为的情况下简化器件的内部结构，可以加快仿真过程的收敛速度，减轻CPU负担。通过多个饼形线圈的叠加，建立了矩形、梯形和倒梯形截面的螺线管磁体模型。与这些模型对应的仿真结果表明，梯形截面的螺线管磁体具有最大的临界电流和最均匀的密度分布。这样的优点不仅降低了超导材料因两端过热而失效的风险，还充分利用了螺线管中间区域线圈的载流能力。
When the current passing through a high temperature superconducting (HTS) coil that exceeds a critical value, the properties of the materials which make up the coil will fail, generating large amounts of heat and even causing serious accidents. Aiming at the above safety problem, this paper took three solenoid magnets with different structures as the object, and conducted a simulation study on their electromagnetic performance through finite element method (FEM). The magnetic field intensity H was taken as the dependent variable of the control equations of the physical field. With the aid of the partial differential equation (PDE) interface of the simulation software used, the control equations were easily constructed. The pancake coil wound by many turns of ribbon conductors was abstracted as a bulk-like conductor with the same cross-sectional area. The main idea of this equivalent replacement is to simplify the internal structure of the device without affecting its electromagnetic behavior, which can accelerate the convergence speed of the simulation process and reduce the CPU burden. Models of solenoid magnets with rectangular, trapezoidal and inverted trapezoidal cross sections were established by stacking many pancake coils. The simulation results corresponding to these models show that the solenoid magnet with trapezoidal cross-section has the largest critical current and most uniform density distribution. Such advantages not only reduce the risk of superconducting material failure due to overheating at both ends, but also fully exploit the current carrying capacity of the coil in the middle area of the solenoid.