Power processing unit
power processing unit (PPU)
In the context of space craft propulsion is a modular or at least self contained spacecraft electrical subsystem responsible for providing electrical power to other subsystems of the spacecraft. PPU needs to be able to cope with varying demands on power output and providing that power in the most efficient manner. There are two main constrains placed on PPU:
1) power generation for instance a solar array or RTG where power generation can vary based on external conditions
2) power utilization - varying depending of the current internal activities performed by the spacecraft (like burst radio transmission) or external like outside temperature and the need to proved electric heat to maintain constant internal temperature
Major considerations in building PPUs are weight, size and efficiency.[1]
Most PPUs process and supply DC (direct current) as such is generated by solar array.