In Orbit (LEO) Point by Point Characterisation of Solar String Technology

摘要

An opportunity to characterise solar cell string(s) in Low Earth Orbit is described. Surrey Satellite Technology Ltd's (SSTL) Technology Demonstration Spacecraft 1 (TDS-1) due for launch into LEO in late 2013 is the first of a series of spacecraft platforms intended for a variety of experimental payloads and platform proving opportunities. A battery bus system based on Maximum Power Point Tracking (MPPT) Battery Charge Regulators (BCRs) uses solar panel temperature measurement to predict a solar panel's MPP. In it's mission mode, the BCR operates in MPPT mode delivering power from a dedicated solar panel to the battery. A second control facility is also incorporated in the design to enable individual BCRs to be operated in a quasi voltage mode which enables the On Board Computer (OBC) to command the BCR's operating point in respect to it's solar panel. Several similar BCR modules operate in parallel permitting one BCR to be dedicated to panel characterisation while the rest maintain mission power needs. Any voltage can be demanded from panel open circuit voltage to approximately 105% of the battery voltage in up to 256 steps. Control over the process will be managed by the OBC. For each step the OBC will record solar panel voltage, current and temperature. To help maintain uniform temperature, the complete end to end sample period is aimed at lasting between 5 and 10 seconds. The next TDS opportunity is in the early planning stage with a target mission consolidation date in 2016. Such opportunities could include solar cell strings mounted on various sun facing spacecraft body panels or deployed panels. A short summary of the various Technology Demonstration Spacecraft (TDS) configurations is given. Areas of interest may include: Aerospace Power Systems, Spacecraft Solar, Spacecraft Solar Arrays, Mars Surface Power.