Power conversion and scaling for vanishingly small satellites with electric propulsion

[摘要] The development of ion electrospray propulsion systems (iEPS) as integrated microelectromechanical systems (i.e. MEMS) effectively miniaturizes propulsion for nanosatellites. Current iEPS thrusters consist of arrays of ion emitters, with a thruster for CubeSat application consisting of hundreds of emitters on a 1 cm² package. As a consequence, the lower bound on the size of satellites incorporating ion-emitter thrusters is not generated by the size of the thrusters themselves but the power supply they require: approximately 1700 volts at hundreds of nanoamps per emitter; a region in parametric space that is poorly explored in terrestrial power converters. We discuss the design and construction of a high-boost-ratio hybrid switched-magnetic/switched-capacitor power supply capable of powering small emitter arrays or single-emitter electrospray propulsion systems. In particular, we discuss the effects of and component requirements necessary for scaling the converter to the size and weight required for a board-level-integrated femtosatellite incorporating several single-emitter thrusters for propulsion and attitude control. This comprises scaling effects for physical and component parameters within a converter topology (such as operating frequency, parasitic effects, and component mass), but also motivates the choice of converter topology, as some are sensitive and others robust to miniaturization.

[发布机构] Massachusetts Institute of Technology