Multikilojoule inductive modulator with solid-state opening switches

A four-stage inductive storage XRAM (inverse MARX) circuit was used to amplify current and power. By means of switching action, individual inductors are charged in series and discharged in parallel to the load. A microprocessor controls the timing of the switches, which results in a predetermined load current waveform. The use of present asymmetric GTOs at much higher currents than rated allowed the amplification and shaping of a 2.5 kA charging current to 9.6 kA at the load. An energy of 25 kJ was transferred to the load, yielding 84% efficiency. The losses were mainly due to the winding resistance of the inductors. With the best-performance commercially available GTOs, this circuit may deliver over 100 kJ with an energy density of 1.6 kJ/kg. Simulation and experimental results are presented.<
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