Effect of Fuse Resistance on EML Capacitor Bank Solid-State Switching

The U.S. Navy is considering the development of an electromagnetic launcher (EML) for surface-fire support and other missions as discussed in. The U.S. Naval Research Laboratory has assembled a facility to develop and test materials for the study of barrel lifetime in electromagnetic launchers (EML) for surface-fire support and other missions as discussed in. The pulsed power system utilizes modules that can be individually triggered to shape the output current pulse. Each bank module consists of capacitors from General Atomics Electronics Systems. The switching thyristors and crowbar diodes are from ABB. A series inductor is used to limit the peak current, isolate modules from each other, and ensure the current is delivered to the test system. Several launch events have been performed, and the pulsed power systems have operated as intended as shown in. The capacitor banks are protected from internal or external capacitor faults using fuses. During low-power operations, the fuses can be considered as wire of constant low resistance. During high power shots, however, the fuses will heat up during discharge and change their resistance similar to. While the current through the thyristors is slightly decreased, most of the effect of the increased resistance after discharge occurs with the freewheeling diodes, dampening the ringing and reducing the peak current. The increased resistance due to heating will be shown at various power levels and the resulting effect on switch action will be demonstrated.