A new structure of mechanical switch used for hybrid breaker in quench protection system

Abstract High power DC breaker is the most important device in the quench protection system of superconducting magnet. In this paper, a new structure mechanical switch with three levels contacts is presented, which is designed for high current hybrid breaker in quench protection system on China Fusion Engineering Test Reactor (CFETR). The topology and operation logic are discussed, and the prototype of hybrid breaker with 10 kA level has been tested.  In addition, the corresponding simulation mode of breaker is built by MATLAB/Simulink. The prototype experimental and simulation analysis prove that the mechanical switch can interrupt the current more quickly and reduce the conducting time of solid-state switch.