Study on DC protection switch for superconducting coils in magnetic confinement fusion device

Abstract

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 15kV/70kA interrupting ability is presented and remains to be resolved.