LTT switch unit for capacitive energy storages

Abstract

When the capacitor cell is discharged in the short-circuit mode, the current pulse amplitude and duration are maximal. Therefore, this mode is the most severe for discharge switches of capacitive energy storage. The characteristics of the transient process of the discharge capacitive energy storage and the current loads acting in the facility discharge circuit have been defined for this mode. The test bench for definition of the LTT (Light Triggered Thyristors) loading capacity is described. The limiting characteristics have been experimentally obtained for LTT, at which there emerges the thermo-generation peak. The process of OFF-ON switching of LTTs has been investigated, the necessity is shown to use the speed-up R-C circuits to ensure fast and stable transition of LTT into the conducting state. The design of the switch unit for the capacitive energy storage comprising LTTs and crowbar diodes is described, and the transient processes of current switching in crowbar diodes are considered. The tests carried out during switching of pu1se current up to 100 kA at a voltage of 6 kV have confirmed the workability of the switch unit. Keywords: Energy storage, Power semiconductor switches, Photothyristors, Pulse power systems