Dielectric Studies in the Development of High Energy Density Pulsed Power Capacitors.

摘要

In an effort to increase the energy density of high voltage capacitors to greater than 5 J/cm3 for compact pulsed power sources, high dielectric constant materials with high dielectric strength are under continued development at the University of Missouri. The materials are modified versions of composites recently developed for compact dielectric-loaded antennas. While the composites developed for antenna systems were developed specifically for use at 100s of MHz to several GHz, the requirements of capacitor applications present unique challenges. In particular, the leakage current must be minimized to efficiently store the energy for long periods of time, and the dielectric losses must be considered at the relatively lower frequencies up to several 10s of MHz. This paper details the dielectric properties of the materials under development for high energy density pulsed power capacitors. The dielectric constant and loss are reported at frequencies relevant for capacitor applications. The leakage current under high voltage conditions is evaluated, and waveforms from the fast discharge of sample capacitors are analyzed. Finally, projections are provided on how the materials may be scaled from small capacitors for dielectric evaluation to full-size prototypes.