Multi-Module, Scalable, High Power Density, Radiation-Hardened Power Converter Interface Systems for Space Rated Li-Ion Battery in Satellite Applicati

ABSTRACT: To significantly reduce procurement overhead and recognizing the mission strategic importance of developing modular power electronics for interfacing the battery to the spacecraft bus, APEI, Inc. is proposing to develop a novel multi-module, inherently scalable, high power density, radiation-hardened, intelligent battery module. The proposed development will focus on the following main technology areas: 1) Rad-hard, inherently scalable, bidirectional power electronics for interfacing with spacecraft distribution bus -- APEI"s patent pending inherently power sharing topology will be incorporated into a suitable switching converter to interface the battery to the spacecraft distribution bus. This technology will yield inherently scalable modules at the topological level. Overall design will utilize newly emerging rad-hard GaN FETs"high efficiency, high switching frequency capabilities to yield unprecedented high power density. 2) Advanced cell level balancing and monitoring circuits --APEI will develop high maturity prototype of the novel cell balancing approach based on selective cell charging through charge energy frequency spreading, and 3) Compact, structural, thermal, and electrical interface for use over a wide range of satellite programsThe objective is simplification in order to develop an elegant, standardized, and readily scalable core intelligent battery module"building block"which provides structural support, efficient heat removal, and straightforward electrical interconnection. BENEFIT: APEI"s converter technology stands out from other modular approaches in that the power sharing is accomplished without the need of inter-module communication; thus, yielding a master-less, fault-tolerant, scalable power converter building block. These converters inherently share current (and thus power) thanks to a novel, patent-pending power topology. APEI"s battery management power converters can be easily combined to form a multi-module arrangement for scalability and/or redundancy purposes. APEI"s advanced, seamlessly scalable, multi-module power converter technology is the key enabler to making the transition from traditional custom designed systems to a standardized battery/power module building block. Our technology will provide the aerospace industry with a fully modular, practical, ready-to-deploy standardized, intelligent battery/power management module. 1) Standardized module = reduced procurement costs 2) Unprecedented efficiency and power density gains through the use of GaN FETs 3) Improved reliability/rad-hard cell balancing circuit (minimal active = device count) Additionally, APEI, Inc. has identified high voltage hybrid electric vehicle (HEV) battery packs as a commercial application of the technology. This application open up a path to non-military commercialization of the technology which can mean huge dividends for APEI, Inc. Specially, the selective charge of individual cells based solely on the frequency components contained in the charge power signal will minimize active device part count while yielding fast, dynamic response to individual cells"state of charge. This approach has great promise not only for space battery applications but also for larger Li-ion cell stacks found in HEVs where 100"s of cells in a stack preclude most traditional cell-balancing approaches from being practically implemented.