High-power MOSFETs and fast-switching thyristors utilized as opening switches for inductive storage systems

Taking aim at the utilization of inductive storage systems with their manifold advantages for pulsed power applications (e.g., higher energy density, lower operating voltage), this paper focuses on semiconductor devices applied as opening switches in the inductive storage circuit. The devices investigated in this study, unipolar power metal-oxide-semiconductor field-effect transistors (MOSFETs) and bipolar thyristors, represent a wide range of power semiconductor switches. At first MOSFETs are investigated in parallel and series configurations, showing a negligible current imbalance and a symmetrical voltage sharing during switch-off. Furthermore, the maximum peak charge current of a single power MOSFET has been evaluated experimentally and theoretically. Overcoming the problem of a thyristor being exclusively a closing switch, we use a technique, called ICCOS, which is based on the well-known parallel capacitor-current commutation principle. Using this technique we have developed a power switch capable of commutating a peak charge current of 18 kA. The switching performance of such a thyristor configuration is compared to an array composed of numerous MOSFETs.