High energy density capacitors

In the German Pulsed Power Components Program, Rheinmetall and Vishay started a joint effort to develop a high energy density capacitor for the 120 mm ETC gun demonstrator. Based on conventional metallized film technology a compact 120 kJ capacitor with an energy density of 2 MJ/m³ was designed and tested with the electric requirements of the ETC gun. Both, performance and lifetime tests were performed with discharge currents up to 45 kA. These tests led to the certification of the capacitor design to be applied in the 120 kJ ETC pulsed power supply module. In the next step improved material and winding designs were realized and tested in order to increase the current characteristics at similar energy densities. In the second design generation current magnitudes up to 100 kA at energy densities of 1.75 J/m³ could be certified for an active armor application. Ongoing developments and tests have the goal to increase the performance and identify the limits of this capacitor technology. In parallel standard capacitor designs are derived from the high energy density development program to be applied in e.g. multimegajoule capacitor systems for high current applications. The paper gives an overview on the different design generations and its test results obtained so far. A first perspective on the performance limits is presented and discussed.