Operation of Multi-Megajoule Inertial-Inductive Pulser

Abstract : The homopolar generator at the Naval Research Laboratory can store up to 4 MJ in the inductor. It has operated at 3.0 MJ level as a source of pulsed energy generated by interrupting the current in the inductor. The magnetic energy has been transferred to resistive and inductive loads using several switching modes. Using an explosively-driven breaker which generates up to 15 kV arc, 40 sec commutation time to resistive load was achieved, with inductor-to-load efficiency of 95%. The addition of fuse switching stages was used to raise the commutation voltage to 200 kV. At this level, a current step-up transformer used as the generator load has been excited in short time ( 100 se c) to generate a 0.5 MA output into a 1 mO load. Fast opening switches in the high-current secondary of the transformer generate high voltage pulses to provide high power output typically associated with low impedance pulse lines. A current step-down transformer was also used to generate long duration ( 0 .2 sec) 10 kA pulses for testing of power line protection equipment .