Studies of Dielectric Breakdown Under Pulsed Power Conditions

In an effort to develop transmission lines with higher energy storage capabilities for compact pulsed power applications, ceramic dielectrics and their electrical breakdown strength (BDS) are being developed and studied. Results of research to-date show that the dense titania ceramics with nanocrystalline grain size (-200 nm) exhibit significantly higher BDS as compared to ceramics made using coarse grain materials when tested under DC conditions. Pulsed testing under similar electric field stresses have been performed and found comparable behavior [1]. Furthering the research has led to consider the electrical breakdown strength (BDS) of materials such as ceramic/epoxy composites. These ceramic/epoxy materials are of interest. This material seems to be more flexible, robust, and might have increased breakdown strength as compared to dense titania ceramics. The powders are available with nominal particle sizes of 50 nm to 400 nm. The crystalline ceramic powders have uniform spherical morphology, precise stoichiometry and high ceramic purity. The effects of rise time of high voltage pulsed power on the breakdown of the ceramic/epoxy composite material will also be the focus of interest. This paper describes our test results, reviews the statistics that are used to analyze the data, and relates our understanding to what has been accumulated in the literature to-date in the context of dielectric breakdown.