Novel crowbar circuit for compact 50-kJ capacitor bank

This paper presents a novel crowbar circuit for a 50 kJ capacitor bank. The crowbar circuit consists of a Rogowski coil, a trigger signal generator, and a triggered vacuum switch (crowbar switch). In our crowbar circuit, the Rogowski coil senses the load current and generates trigger signals at the correct time for the crowbar switch operation. At full capacitor charge voltage of 22 kV, it was possible to keep the reverse voltage of the capacitor below 15% of charging voltage. In this paper, we report the features of our crowbar switch system and the electrical performance of the crowbar system.