面向电力应用的高温超导线圈励磁方案优化研究

Research on excitation scheme for high temperature superconducting coil for power applications

无绝缘高温超导(NI HTS)磁体线圈由于自身电感和特征电阻,在通流励磁期间会产生励磁延迟和匝间损耗。本文在传统NI HTS磁体线圈等效电路模型的基础上,考虑接头电阻对大型磁体线圈的影响,提出改进型集总参数等效电路模型,然后以大型NI HTS磁体线圈为研究对象,通过仿真分析不同电源通流速度下磁体线圈中环向电流和径向电流的分布情况,得到降低励磁速度可有效抑制励磁延迟并降低匝间损耗的结论。在此基础上,创新性提出一种新型阶梯式励磁方案,研究发现阶梯高度与匝间损耗呈线性正相关,且在相同通流速度下电流阶梯高度为目标电流的十分之一时的匝间损耗对比直接励磁时可减少约90%。

Due to inductance and characteristic resistance,theno-insulated high-temperature superconducting magnet coils will experience excitation delay and inter turn loss during current excitation.On the basis of the traditional NI HTS coil equivalent circuit model,this paper considered the influence of joint resistance on large magnet coils and proposed an improved lumped parameter equivalent circuit model.Taking the large NI HTS magnet coil as the research object,the distribution of circumferential and radial currents in the magnet coils under different power supply flow rates was simulated and analyzed.It was concluded that reducing excitation speed can effectively suppress excitation delay and reduce inter turn losses.On this basis,an innovative stepped excitation scheme was proposed.It is found a linear positive correlation between step height and inter turn loss.When the current step height is one tenth of the target current,the inter turn loss can be reduced by about 90%compared to direct excitation at the same current flow rate.