Power

Objective

The goal of the Illinois CubeSat Power team is to provide stable and reliable power to all satellite subsystems. Our board translates solar energy into power that can charge the on-board lithium-ion batteries. The batteries supply power to the satellite even while in the eclipsed part of the orbit. Our board also uses DC/DC converters to regulate our output voltage into several different buses that are required by each subsystem. The board is also equipped with circuitry to distribute power to the respective subsystems when needed.

Batteries

The main power supply to the satellite besides the solar panels is the battery. We will be using a rechargeable Li-Ion battery and it will be constantly charged with the help of the charging circuit and solar panels. Since not all the solar panels will be generating power all the time, we need to rely on the batteries to power up the systems on the satellite. Therefore, choosing a good and efficient battery is very important.

Over-current Protection

All the regulated and unregulated voltage lines will be having a double redundant over-current protection circuitry to protect the systems on-board. This circuit has the ability to monitor the current on each of the voltage line and isolate the fault if necessary. This circuit will work with the help of the on-board power micro-controller.

Testing

As the power team, we value testing very highly. To ensure all of our components function correctly we take strides to test in as many conditions as possible. One interesting project we are working on building is a solar simulator. Our goal is to be able to replicate the solar flux seen in space in order to test our solar panels response in different parts of orbit. Our results of these tests and others like it help us to design the most efficient and reliable power boards possible.

Power Requirements

Our power board is required to output three different voltage buses which are an unregulated bus, 5 V, and 3.3 V. Different subsystems and components require different voltages and we must ensure everything has the power needed when necessary. When unexpected conditions occur the power board must still ensure it can deliver power to reboot or correct the system.

Copyright University of Illinois at Urbana-Champaign 2008