Power processing unit

In the context of spacecraft, the power processing unit (PPU) is a module containing the electrical subsystem responsible for providing electrical power to other parts of the spacecraft. The PPU needs to be able to cope with varying demands for power output and provide that power in the most efficient manner possible.

There are two main constrains placed on PPU:

• Power generation from for instance a solar array or radioisotope thermoelectric generator where power generation can vary based on external conditions.
• Power utilization which varyies depending of the current internal activities performed by the spacecraft such as burst radio transmission or external demand factors like outside temperature and the need to provide heat to maintain constant internal temperature.

Major considerations in building PPUs are weight, size and efficiency.

Most PPUs process and supply direct current because that is what is generated by a solar array.

The PPU is also responsible for voltage conversion and supplying the required voltage to other subsystems of the spacecraft.