Conceptual design of high power hybrid DC switch for China Fusion Engineering Experiment Reactor

The rated parameters of quench protection switch for China Fusion Engineering Experiment Reactor(CFETR) are up to 10 kV/±100 kA. In this paper, a hybrid DC switch is proposed to meet the requirements. The hybrid switch contains an innovative mechanical bypass switch with three levels contacts for conducting the continuous current, which can reduce the on-state time of solid-state switch. The bi-directional solid-state switch is composed of diode bridge and IGBTs. The analysis of junction temperature proves that the maximum allowable current of IGBTs can be improved. In addition, high current interruption experiments of the basic unit topology were carried out to verify the feasibility of the design.