多超导线圈并联下的电流分布研究

Study on the current distribution of parallel multi HTS coils

与多超导线圈串联相比,多超导线圈并联通流的电流分布特性比较复杂。本文提出一种基于H方程和均质化方法的有限元模型,研究了4 YBCO单饼线圈并联下的电流分布,并与场路耦合模型对比。仿真结果表明,多超导线圈并联下的电流分布与各线圈的接头电阻、等效电感和等效超导电阻有关。线圈失超之前,各线圈的等效超导电阻几乎可以忽略,电流分布主要受线圈的接头电阻和等效电感控制;线圈开始失超后,电流分布主要受等效超导电阻影响,电流会重新分配,最终各线圈稳流值与各线圈的临界电流有关。

Comparing with multi HTS coils in series, the current distributions of multi HTS coils in parallel connection are relatively complex. In this paper, a FEM model based on H -formulation and homogenization method was presented to study the current distributions of four YBCO single pancake coils in parallel connection, and was compared with the field - circuit coupled model. The simulation results shows that the current distributions of multi HTS pancake coils in parallel connection depend on the termination resistance, equivalent inductance and equivalent HTS resistance of each pancake coil. Before quenching, the current in each pancake coil is determined by the termination resistance and equivalent inductance. When the pancake coils start to quench, the current in each pancake coil is controlled and redistributed by the equivalent HTS resistances of these pancake coils, and the final steady currents are related to the critical currents of these pancake coils.