UPSat’s Electrical Power Subsystem (EPS) module provides, stores, distributes and controls CubeSat’s electrical power. In fact it absorbs energy from photo-voltaic cells and supplies it to the system under the appropriate voltage levels. A battery storage system is also used in order to feed the load when the energy produced by the PV cell is not sufficient and to store the excessive energy whenever it is possible. For the selection of the appropriate configuration, the mission profile of the UPSat has to be studied, in order to evaluate the environmental conditions as well as the energy required by the satellite’s subsystems, such as the Communication and the ADCS subsystem.
- Seven high efficiency (30%) PV cells connected in parallel and to a battery array through high efficiency voltage step-up boost converters
- Implementation of the P&O MPPT algorithm through the EPS microcontroller
- Battery Array: 3 Li-Po batteries (3.7V, 4Ah) and its voltage varies 6V ~ 8.4V
- MOSFET switches for power distribution, in order to cut off the consumption if necessary
- The mass of the developed EPS is 318g (PV cells: 22g, batteries: 46g, boards: 250g).
Power Budget – Generation and Consumption