An all solid state fault interrupter using gto's

There exists an acute need for a solid state fault interrupter capable of operating at high voltages and/or high currents, for such applications as command chargers, electromagnetic launchers and other high power conditioning applications. The gate turn-off thyristor (GTO) is suited for this task. This requires series connection of several devices and their support systems (electronic and thermal). Reliable operation depends on devising a control algorithm that will cause the individual GTO's to conduct and recover simultaneously. Computer simulation shows that a window of 100 ns is required, during which time all devices must alter from on to off state, and vice versa, to prevent overvoltages on any device of the chain. A first milestone is the construction and testing of a 5 kV series GTO based switch at modest current densities. Operation of the 5 kV series stack will be compared to the computer simulation, showing excellent agreement. This work is supported by the U.S. Army Electronics Technology and Devices Laboratory.