Foresail-1 Electrical Power System

The Electrical Power System (EPS) for the Foresail-1 CubeSat was developed by Aalto University as part of the Finnish Centre of Excellence in Sustainable Space. The system consists of two main components: the power conditioning and distribution unit (PCDU) and the battery board. Together, these manage power generation, storage, and distribution for the satellite's systems and payloads.

The battery board uses a 2p2s configuration of four Panasonic NCR-18650B lithium-ion cells, which includes battery management functionalities like heating, cell balancing, and protection. The PCDU distributes two voltage rails: two unregulated battery voltage rails (6-8.2 V) and six regulated 3.6 V rails, allowing for more flexibility and control in the power supply for subsystems.

At the core of the EPS is a custom Maximum Power Point Tracking (MPPT) battery charge regulator that maximizes the solar panel's power output. It uses a 32-bit ARM Cortex-M0 Vorago microcontroller, designed to withstand space radiation. This controller runs a custom MPPT algorithm to optimize power generation, even in dynamic conditions, while ensuring efficient battery charging.

The Foresail-1 EPS underwent rigorous testing, including thermal-vacuum, radiation, and vibration tests, to verify its functionality and performance. Though designed for Foresail-1’s low-Earth orbit mission, the EPS was also built with geostationary transfer orbit (GTO) in mind, where higher radiation levels and more complex payloads demand robust power solutions.
 

More information:

Lead Engineer Kiril Cheremetiev ([email protected])