A Predictive Method for Switching Time of Nanosecond Pulsed Power System of Ohmic Loads Using SiC MOSFETs

In this paper, a predictive method for accurately determining the switching time of nanosecond pulsed power system is proposed, which is important to evaluate and better design higher-grade pulse power system. Compared to the traditional predictive method of switching time, the ohmic loads and nonlinearity of capacitances are considered in the proposed method. In detail, the expressions of the switching time are deduced, in which, the main parasitic elements affecting the switching transient are considered. In order to verify the validity of the method, an ohmic-load double pulse circuit is established. The experimental device is a CREE SiC MOSFET module CAS325M12HM2 (1200V/325A). The predictive results of the proposed method are compared with experiments and the traditional predictive method under different voltages and currents. The comparison results show that the proposed method has a good agreement with experiments and has better predictive accuracy than the traditional method, which verifies the effectiveness and accuracy. The method of prediction the switching time of nanosecond pulsed power system of ohmic loads using SiC MOSFETs offers a theoretical reference to evaluate and improve pulse power systems.