大电流高精度大动态范围脉冲电源关键技术研究

Superconducting magnet technology is one of the key magnet system technologies which makes particle accelerator higher stronger better, used by large accelerator facility in the world that is or will be in the construction. The inductance of superconducting magnet is large, from several to dozens of Henry, but the Impedance is zero(except the lead resistance of load), so the parameters between conventional magnet and superconducting magnet have great differences and the superconducting power supply is too which feeds the superconducting magnet. In pulse operation mode, at the current ramp-up level, power supply need output high excitation voltage, to ensure that the current rise; In the flat-top level of pulse current, the load exhibits a resistance, the output voltage of the power supply becomes small; In the rump-down level, the load will release energy, so the power supply will need withstand extremely high reverse voltage, at the same time pulsed superconducting power supply ensure high precision current, low ripple throughout the pulse period, and control the load feedback energy safely and efficiently. There are new questions much to solve in the process. Based on this, through the study of this subject, to Analysis these issues, and propose solutions for the future accelerator development, research and technology reserves.

超导磁铁技术是粒子加速器向更高、更强、更好方向发展过程中磁场系统的关键技术之一，被目前国际上正在或将要建设的大型加速器越来越多地所采用。超导磁铁感抗极大，从几亨到几十亨，而阻抗为零（负载引线电阻除外），与常规磁铁相比有很大差别。为超导磁铁励磁的超导电源，特别是脉冲运行的超导电源与常规磁铁电源相比也有非常大的区别。在脉冲运行时，在电流上升段，感性电源需要输出较高的强激电压，以保证电流上升；在脉冲电流平顶段，负载呈现为阻性，电源输出电压迅速变小；在脉冲的下降段，负载要释放能量，电源又需承受极高的反向电压，同时脉冲超导电源在整个脉冲周期内保证输出电流高精度、低纹波，对负载反馈能量的安全高效控制等。以上过程中有太多的新问题需要解决。基于此，通过本课题的研究，对以上问题进行分析，并提出解决方案，为今后加速器发展做预研和技术储备。

强流重离子加速器装置HIAF（High intensity Heavy-ion Accelerate Facility），是一台国际领先水平的重离子加速器综合研究装置，由强流超导离子源、强流超导离子直线加速器、环形增强器、高精度环形谱仪、低能辐照终端、放射性束流线、外靶实验终端等构成，部分系统采用了全超导磁铁，这种大规模应用超导磁铁在国内加速器装置上是首次。对超导磁铁励磁的超导电源，与常规电源相比，国内一些关键技术还不成熟。本课题主要研究了大电流、高精度超导脉冲电源的拓扑机构，高速高精度的控制策略和超导磁铁励磁时能量的处理技术等；通过本课题的开展，深入分析了适合于大电流、高精度脉冲电源的拓扑，同时针对相应拓扑结构的控制策略也做了对应的仿真，对于负载能量的处理技术也做了实际测试和验证；针对大电流、高精度的拓扑结构的实现拟采用多个功率模块级联的方式，并且对功率模块进行了测试，同时对采用SVPWM技术实现负载能量的回馈方式也做了样机验证，获得了较好的实验数据，积累了应用于加速器超导励磁电源的关键技术，是HIAF装置中超导电源大规模应用的强力技术支撑。