基于有限元的高温超导线圈临界电流快速算法

摘要

High temperature superconducting (HTS) coils are widely applied in power equipment.Under the complex electromagnetic environment inside the power equipment,how to quickly and precisely evaluate the critical current,which is recognized as one of the key parameters for HTS coils,is of vital importance for the superconducting application.Based on the finite element method (FEM),the H-formulation model and the magnetic field (referred to as MF) equivalent model were applied to evaluate the critical current of a double-layer HTS pancake coil.Results of two models show great consistency and reasons for the high efficiency of MF equivalent model are analyzed detailedly.The MF equivalent model is extended to HTS coils with flux diverter.Further caculations about the effect,produced by flux diverters under the condition of different external fields,on the critical current are performed,and the surge of electric field in end parts of coils with flux diverter is found to be the major cause for the critical current reducement.%超导线圈在电力设备中应用广泛.临界电流作为超导线圈的一项重要参数,在电力设备复杂的电磁环境中快速和准确预测线圈的临界电流是非常重要的.基于有限元(FEM),分别使用H方程模型与磁场(简称:MF)等效模型对一个双层的高温超导线圈临界电流进行了计算,两种模型的仿真结果一致,并分析了MF等效模型仿真快速高效的原因.将MF等效模型拓展至含分磁环的超导线圈中,进一步计算不同外场条件下分磁环对临界电流的影响,并发现分磁环影响下的端部电场激升是线圈临界电流下降的主要原因.