A Scalable Approach for Optimized Power Management in CubeSats

CubeSats have revolutionized space research by providing low cost platforms with small form factors fit for a variety of space missions. However, the Electrical Power System (EPS) remains a crucial and challenging area with evolving demands of reliability, modularity, and efficiency. This paper presents a scalable and fault-tolerant EPS for 2U cubesats and above, featuring Maximum Power Point Tracking (MPPT), a dual layered Battery Management System (BMS), and an MCU-based supervisory unit. Designed with modularity in mind, this system enables component upgrade without major design overhaul, additionally the proposed system has heightened fault tolerance through incorporation of an automatic backup power sub-system in the event of failure. A detailed power budget analysis revealed a total system load of 1.458W, distributed across telemetry (20mW), payload (1.4W), and communication subsystems (38mW). The EPS is powered by a primary three-cell lithium-ion battery pack (11.1V, 1800mAh per cell, 19.98Wh total) and a solar array of five 12V, 2.1W panels. Under optimal conditions, three of these panels can fully charge the battery in approximately 3.43 hours with a solar irradiance of 1370 W/m<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>. The system also incorporates an MCU-based supervisory module (LGT8F32P), enabling real-time power monitoring, fault detection, and automated power source switching. Simulation results validated the system’s performance in terms of power regulation, fault tolerance, and emergency power switching, with a working breadboard prototype demonstrating its viability. The proposed EPS creates a new benchmark in CubeSat power architectures by optimizing mission reliability, flexibility, and energy efficiency.