Lightweight High Energy Density Capacitors for NASA AMPS and PPUs

This NASA Phase I SBIR proposal addresses the development of lightweight, high energy density DC-link capacitors that are a key component of inverters used power processing units (PPUs). DC-link capacitors used in IGBT and MOSFET switching circuits are one of the largest and least reliable components in DC-DC and DC-AC inverter circuits. Tantalum capacitors used currently by NASA in such circuits, have significant parametric limitations in the temperature range of -125oC to >200oC. This development proposes the replacement of electrolytic capacitors with high temperature, solid state, Polymer Multilayer (PML) capacitors that have been recently developed for automotive inverter applications. PML polymer dielectrics can be used to produce capacitors with voltages in the range of 25V to 1000V. The high temperature PML polymers are amorphous with very high breakdown strength and can operate in a temperature range of -196oC to >200oC. PML capacitors are smaller than tantalums, they have 10X lower weight, lower leakage current, lower dissipation factor, lower inductance and lower equivalent series resistance (ESR). The Phase I development will focus in producing and evaluating PML capacitors designed for PPUs utilized in Hall thrusters and roll-out PV arrays for solar electric propulsion.