Modular and Highly Reliable COTS-Based Power Conditioning and Distribution Unit for Small Satellites

This paper presents a modular Power Conditioning and Distribution Unit (PCDU) designed for small satellites. The proposed system features a highly adaptable architecture capable of managing a total power throughput of up to 100 W, with specific limits defined by mission-dependent thermal and redundancy configurations. Aligned with the New Space paradigm, the implementation relies on Commercial Off-The-Shelf (COTS) components, a strategy that drastically reduces development and manufacturing costs without compromising reliability. The system has been optimized for operation in harsh environments, including high vacuum, ionizing radiation, and extreme thermal gradients. The design incorporates strict redundancy and fault-tolerance criteria to provide a robust solution for critical subsystems. Comprehensive validation was performed through functional testing, Total Ionizing Dose (TID) radiation campaigns, and Thermal Vacuum (TVAC) cycles. Experimental results demonstrate that the PCDU withstands high-vacuum thermal cycling and cumulative radiation doses exceeding 75 kRad. These findings confirm that the developed unit is a cost-effective, high-reliability solution suitable for both Low Earth Orbit (LEO) and deep-space missions.