核聚变装置中直流保护开关的研究进展

Study on DC protection switch for Superconducting Coils in Magnetic Confinement Fusion Device

磁约束型聚变装置采用超导线圈流通强直流来产生高强磁场,约束高温等离子体进行聚变实验。因此,失超保护系统尤其是直流保护开关的设计极为重要。随着线圈电流的增大,设计了各种不同的开关结构来满足不断提高的开断参数的需求。总结了国内外超导聚变装置中的直流保护开关技术的发展,描述了经典的机械开关、人工电流过零关断开关的应用,介绍了先进全控器件混合式直流开关的最新研究进展,并描述了正在研究中的用于中国聚变工程实验堆(China fusion engineering test reactor,CFETR)的15k V/70k A混合式直流开关的设计挑战。

For the purpose of realizing high-intensity magnetic field by high direct current for confining plasma,modern magnetic confinement fusion devises are made up of expensive and complicated superconducting coils. Thus the quench protection system which contains dc breaker is particularly important for the safety operation of the coil. Various structures of DC protection breaker have been designed to meet the increasing coil current. This paper summarized the DC breaker topologies used in fusion devices, described the application of classical mechanical switch and artificial current zero-crossing breaker, and introduced the new development of advanced hybrid DC switch. Furthermore, a research challenge of IGBT hybrid DC switch for China fusion engineering test reactor(CFETR) with 15 k V/70 k A interrupting ability is presented and remains to be resolved.