双定子场调制超导电机超导磁体电磁特性的分析与计算

Analysis and Calculation of Electromagnetic Characteristics of Superconducting Magnet Used in Double Stator Field-modulated Superconducting Machine

双定子场调制高温超导电机(double-stator field-modulated high temperature superconducting machine,DSFM-HTSM)是一种新型超导电机,其使用高温超导(hightemperature superconducting,HTS)磁体励磁,且实现HTS磁体的静态密封冷却与电机的无刷化。针对10kW DSFM-HTSM样机使用的100匝BSCCO双饼线圈,结合超导临界态模型和麦克斯韦方程建立其二维电磁场有限元计算模型,对HTS线圈的自场通流过程进行数值模拟,得到线圈电流的分布与变化特征,并求得线圈临界电流;采用边界替换法,对电机额定运行下的HTS线圈进行快速的电磁场有限元计算,求得HTS线圈的交流损耗;最后进行HTS磁体的制造和实验测试,在液氮冷却下线圈临界电流达70A,与理论计算值相符;样机稳定运行,HTS磁体满足设计要求,验证所提分析计算方法的正确性和有效性。

Recently,a novel double-stator field-modulated high temperature superconducting machine(DSFM-HTSM)was proposed,using high temperature superconducting(HTS)coils for excitation,which realized stationary-seal cooling of the HTS magnet and brushless of the machine.In this paper,aiming at the 100-turns BSCCO double-pancake coils used in 10kW DSFM-HTSM prototype,the 2-D electromagnetic-field finite-element calculation model was established based on superconducting critical state model and Maxwell’s equations.The current-rising process of the HTS coils under self-field was numerically simulated by this model,the distribution and variation characteristics of coil current were analyzed,and then the critical current of the coils was obtained.Fast electromagnetic-field finite-element calculation of the HTS coils in the machine under rated operation was performed by the boundary-replacement method,and the AC loss of the HTS coils was calculated.Finally,the manufacture and experimental tests of the HTS magnets were carried out.The test results show that the critical current of the coils can reach 70A when cooled by liquid nitrogen,which is consistent with the calculation.The prototype machine runs stably,and the HTS magnet meets the design requirements,verifying the correctness and effectiveness of the analysis and calculation method established in this paper.