**3. Test Configuration**

As shown in Figure 9, the test platform is mainly composed of an *LC* oscillation circuit, NHCB, controller, and data acquisition system. The *LC* oscillation circuit is composed of a capacitor *Ci* and an inductance *Li*, and is mainly used to generate the large current required for the experiment. *Km* is the experimental control switch, responsible for introducing current into NHCB. *Kv* represents the MS of NHCB. The SS of NHCB is mainly composed of impedance *Za* and the IGBT module, and the impedance *Za* is formed by the inductance *La* and the resistance *Ra* in series. The on-state resistance and stray inductance of the SS are changed by changing *Ra* and *La*, respectively, to explore the e ffects of on-state resistance and stray inductance on vacuum arc commutation characteristics of NHCB. The IGBT selected in this experiment is CM1000HA-24H, the collector current of a single CM1000HA-24H is up to 2 kA, and two IGBTs are connected in parallel to form an IGBT module. Ct1 and Ct2 are current sensors, which are used to collect the currents of the MS and SS branches, respectively. Pt is a voltage sensor used to collect the vacuum arc voltage. The controller is used to control the operation sequence of the entire experiment. The data acquisition system is used for data collection and display.

**Figure 9.** Vacuum arc commutation test platform.
