0.5 MW 60 kHz solid state power modulator

The authors describe the design, construction, and test results of a 0.5 MW average power solid-state modulator which produces square pulses at variable voltages up to 5.5 kV and repetition rates up to 60 kHz. This modulator generates current pulses with peak amplitudes of 700 A and risetimes of less than 500 ns (10-90%) into a nonlinear load which is also subject to frequent open-circuit or short-circuit faults. Modulation is performed by a series and shunt switch, each made up of a large array of power MOSFET devices. Redundant fault protection, including a novel technique for implementing a saturable reactor as a fault limiter, is provided to ensure system survival during the many load-short-circuit faults expected in normal operation. It is concluded that the operation of this pulsed power supply has met or exceeded all of the critical design goals, including switched voltage, peak current, root-mean-square current, average current and repetition rate