Demonstration of compact solid-state opening and closing switch utilizing GTOs in series

A compact opening and closing solid-state switch was designed, constructed, and demonstrated. The switch repetitively switches over 4 MW of peak power and yet is only 0.45 m by 0.12 m by 0.32 m and has a mass of 13 kg. The switch uses commercially available gate turn-off thyristors (GTOs), arranged in series to enable the collected devices to switch a voltage five times the rating of an individual device. The system uses commercially available components exclusively, yet takes advantage of state-of-the-art components. These include multilayer ceramic capacitors which are arrayed to produce a snubber capacitor, and small high-voltage isolated power transformers that protect each of the seven GTO stages from breakdown damage via their power supplies. Each stage is controlled via a fiber-optic link, and turn-on and turn-off times are adjustable for each of the seven stages. System dV/ dt exceeded 1 kV/μs and system di/dt exceeded 200 A/μs, for both turn-on and turn-off. The system was only limited in the amount of power it could switch by thermal considerations. A much higher power could be switched if there were advanced cooling. The cooling devices were quite modest, in that this was only a demonstration of the principle