Research is proposed on a novel solid state electric circuit breaker. The device can be used as a large-scale (400 kV, 1 kA) industrial or utility circuit interrupter. The proposed device has the potential to significantly extend the performance of existing circuit breakers by simultaneously increasing the rate of change of current, di/dt, and the resulting rate change in system voltage, dV/dt. The proposed research involves analytical calculations and experimental tests of a scaled-down circuit breaker device. The investigator will independently test the di/dt and dV/dt performance of a small scale device. Fast acting, high power AC circuit breakers have application in general electric-power applications and would provide an improved performance level that has not been attained to this point.