Progress of DC Quench Protection Switch for Superconducting Fusion Reactors

The superconducting magnets are the most expensive and important components for a magnetic confinement thermonuclear fusion device. The high-intensity magnetic fields produced by high density DC current are used to confine and shape the high-temperature plasma in experiments. Therefore, the study of DC quench protection switches is extremely necessary and meaningful for the safety operation of superconducting magnets. Different types of switch have been studied based on various circuit requirements and parameters, such as interruption time, current and voltage. This paper reviewed the developing process of quench protection switch and summarized the respective characteristics of direct interruption commutation switch, artificial zero-crossing commutation switch and full-controlled active commutation switch. Finally, the paper expounded the recent development of three-level contacts hybrid DC breaker technology for next generation fusion reactor.