Okay.. So our CubeSat power supply subsystem should have batteries. There will probably be some solar cells to. Something else too?
The system level design is done after ESTCube-1 power system. Public information about it is available in the article.
- Two lithium ion cells in parallel
- Both are two way current limited
- Current limits have auto retry
- Enable signals are connected to controller
- Temperature monitoring
- Optional: Some kind of heater (pcb track)
In case of one battery failure the satellite can still operate. Batteries are connected through protection to a net named Main Power Bus (MPB).
- SPV1040 maximum power point tracking boost converter
- 6 or 12 channels
- Each solar cell is in parallel with others. You can smash 11 of the 12 cells and still have a working satellite.
- If it makes channels smaller - I will use ideal diode controllers before MPPT to reduce number of MPPTs needed.
- If it is needed - ideal diodes between SPV1040 output and Main Power Bus
- Parallel regulators on 3.3 V, 5 V and 12 V rails
- Output current limits/ideal diodes
- If needed - input current limits
- If regulators are wimpy and there is room - more than 1 power rail to all voltages.
- We will have a microcontroller monitoring everithing (MSP430FR or maybe Arduino)
- All FAULT signals are connected to MCU
- Reasonable amount of enable-disable lines
- Digital communication with other subsystems (SPI, UART or I2C)
- Possibility for zombie check signals from other subsystems (to function as a watchdog)
- Battery voltage measurement
- As much other voltage measurements as possible