Re: Future radical satellite designs
I have mentioned this before and will again: Why not construct clusters of low voltage batteries each with their own set of solar cells. Then each low voltage battery ( 3 volts or so) has its own boost voltage converter to charge to a much higher voltage bus (15-24 volts). In this way, the failure or depletion of a battery will affect only the available current on the bus, not the voltage.
The solar cells could then be placed on all sides of the spacecraft and charge their associated batteries at will, with no concern of having the entire solar cell array in same plane with the sun as there would be with a high voltage string of solar cells.
Why not construct clusters of low voltage batteries each with their own set of solar cells. ... The solar cells could then be placed on all sides of the spacecraft and charge their associated batteries at will...
Yes, this was our design back in the mid 90's for a tiny softball sized satellite. A single NiCd per side with a magnet for tumble and radiative B/W paint for spin to assure even illumination. Each cell was charged by itself, and the series string was used to power the spacecraft (6 times 1.2v) to give a nice 7.2/8.4v bus.
It solves the number one problem of spaceccraft batteries, that is, charging and discharging in series. Also, no inefficiences of boost inverters.. Penalty was that cells had to have larger capacities because each one would see less charge time.
Bob, WB4APR
The difference in my proposal is that instead of a series string, each solar cell/battery assembly have its own boost convertor/regulator to charge a common bus to a higher operating voltage. That way, a failure or depletion a small number of batteries will affect only the available bus current, not the bus voltage.
Robert Bruninga wrote:
Why not construct clusters of low voltage batteries each with their own set of solar cells. ... The solar cells could then be placed on all sides of the spacecraft and charge their associated batteries at will...
Yes, this was our design back in the mid 90's for a tiny softball sized satellite. A single NiCd per side with a magnet for tumble and radiative B/W paint for spin to assure even illumination. Each cell was charged by itself, and the series string was used to power the spacecraft (6 times 1.2v) to give a nice 7.2/8.4v bus.
It solves the number one problem of spaceccraft batteries, that is, charging and discharging in series. Also, no inefficiences of boost inverters.. Penalty was that cells had to have larger capacities because each one would see less charge time.
Bob, WB4APR
participants (2)
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Joe Leikhim -
Robert Bruninga