Topology Analysis of Full-Controlled Hybrid Switching Network in Fusion Device

Switching network unit (SNU) of fusion device excites the plasma and finally establishes the plasma current. The full-controlled hybrid scheme is the research trend and hotspot of SNU in a nuclear fusion device. Based on the analysis of the SNU schemes in the current fusion devices, two kinds of full-controlled hybrid circuits are compared and analyzed. Through the principle analysis, theoretical calculation, and model simulation under 50 kA, the system operation process and the influence of arc voltage and other related parameters on the operation process are studied and discussed. Finally, the main characteristics and applicable conditions of the two circuits are described. At the same time, the aspects needing attention in circuit design are explained. The research shows that the basic circuit is suitable for high-current circuits, and the multistage commutation circuit is suitable for high-voltage circuits. The above study can provide a useful reference for the design of full-controlled hybrid SNU.