Li-ion autonomous battery module for space vehicles
- Paper number
IAC-06-B5.6.15
- Author
Mr. Carlo Del Vecchio Blanco, University of Naples "Federico II", Italy
- Coauthor
Prof. Marco D Errico, Seconda Universita di Napoli, Italy
- Year
2006
- Abstract
The challenge in present and future satellites design is the realization of highly miniaturized platforms with high performance, low cost, and adaptability to a large number of different missions. A modular approach can be the answer to this needs. Modularity advantages are enhanced by a platform approach: i.e. modularity is achieved at component and subsystem levels with the possibility to multiply components to meet different requirements and to simply insert and upgrade new modules without redesigning the overall satellite. In addition, if intelligent modules are considered, an internal autonomy is introduced leaving to the on-board computer only system-level tasks. Moreover, increase or decrease of integrated modules is simplified. In the case of the electrical power subsystem (EPS), this approach offers an additional and welcome advantage. If the satellite power management capability is spread over a number of power modules, each module is characterized by low power levels which open the way to the utilization of a number of high performance, low cost off-the-shelf components (COTS). These concepts are applied in the proposed paper to the design and realization of a battery module. It relies on Li-ion terrestrial cells, COTS integrated circuits (ICs), COTS microcontroller (µC), and CAN bus as data interface. A thorough market analysis of terrestrial cells led to the identification of SAFT® MP series, which are integrated in a 5.5Ah 6-cell string. Integrated charge/discharge electronics build on Linear Technology ICs. In particular, constant current, constant voltage charge profile is realized by means of LTC4008, while discharge is performed through a boost voltage DC/DC converter driven by LT3782. Monitoring of module status and correcting actions can be autonomously performed by an embedded µC (PIC18F258), which is also able to communicate with the on-board computer by means of its internal capability to implement CAN bus connection. Battery design is verified by a test campaign aimed at performance characterization. The realized module supplies 95-98 Wh, depending on the discharge current, with an overall charge/discharge total efficiency of 0.74 at 1A and a maximum currents of 4A. The total module mass is 1.6 Kg with associated volume of 1.04 dm3, with a component cost of around euro 1,000. Battery design is finally validated by thermal-vacuum tests. Then, a radiation environment characterization is planned for the main COTS components, considering both Total Ionizing Dose (TID) and Single Event Effects (SEE). Test campaign is under way and results will be reported in the paper.
- Abstract document
- Manuscript document
IAC-06-B5.6.15.pdf (🔒 authorized access only).
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