NASA SBIR 2003 Solicitation


PROPOSAL NUMBER:03-F1.01-8237 (For NASA Use Only - Chron: 034768)
SUBTOPIC TITLE:Process and Human Factors Engineering Technologies
PROPOSAL TITLE:Three Phase Resonant DC Power Converter for Ion Thrusters

SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Colorado Power Electronics, Inc.
200 Commerce, Unit F
Fort Collins ,CO 80524 - 2746
(970) 482 - 0191

PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Geoffrey N. Drummond
200 Commerce, Unit F
Fort Collins ,CO  80524 -2746
(970) 482 - 0191
U.S. Citizen or Legal Resident: Yes

The new generation of, high performance electric propulsion missions will require high mass throughput and most likely the use of grided ion thruster equipped with carbon based grids will be required to meet the extremely high life requirements. However, because of the high susceptibility of these carbon based grids to damage during recycle event they will require a low stored energy beam power DC-DC converter. An innovative three-phase resonant DC converter, which produces high levels of DC beam power with minimal stored energy is proposed. This new design combines proven industrial technologies with a innovative new design that relies on combined outputs of phase-shifted converters to produce a low ripple DC voltage without output filtering. It is anticipated that stored energy can be reduced by two orders of magnitude when compared to the ?present state of the art? converters. Additionally, the resonant power conversion topology facilitates both higher switching frequencies and power densities, which in turn lowers power module mass. Once complete, these new DC-DC converters will significantly increase the current state of the art by reducing both the stored output energy and mass of the beam DC-DC converter. These changes will enable the present state of the art carbon based grids to obtain the required life for high performance deep space missions.

The primary market for this technology is for the high power beam converters for grided ion propulsion systems. However, we are not limited exclusively to this application. Because the outputs of the converters can be tailored for other current and voltage levels, these converters would work for the discharge supplies for both ion and hall thruster systems. In addition to the flight applications for DC converters there exists an even larger market for the ground testing and research on electric propulsion systems. There could be significant advantage in developing the flight version of an electric propulsion system using the same power supply configuration as the flight version.

A new commercial application appears to be Electronic Power Conditioners (EPC) for Traveling Wave Tube Amplifiers (TWTA). The low output ripple reduces the filter capacitor size requirements in high voltage power supplies. The lower stored energy will minimize arc damage and improve reliability.