Design and Implementation of a Power Management System for the SÓLFAR Hybrid UAV

With the ever-changing global climate, forest fires are becoming an increasingly severe problem. To address this issue, the SÓLFAR project is being developed as a collaboration between KTH Royal Institute of Technology (KTH) and the South African company EnviroVision Solutions. The aim of the project is to design a solar-powered Unmanned Aerial Vehicle (UAV) that can be used for aerial surveillance to facilitate early detection of forest fires. The SÓLFAR UAV is still under development and currently lacks a functional power management system. The goal is to integrate Photovoltaics (PVs) with Lithium ion (Li-ion) batteries in a hybrid configuration to extend flight duration. While PVs have proven to be viable in UAVs, efficiently harvesting solar energy remains a challenge. This is typically addressed using Maximum Power Point Tracking (MPPT) technology. Due to fluctuating irradiance levels, a battery backup is essential to ensure continuous operation. The primary challenge is to integrate the PVs, Li-ion batteries, and the onboard electronics into a cohesive system. The system must dynamically manage power distribution by charging the batteries when solar power is abundant and supplementing power from the batteries when solar energy is insufficient. The purpose of this thesis was to evaluate an existing design for the SÓLFAR UAV, refine it, and develop an improved power management system. This was achieved through software simulations, hardware design and production, and programming of both an Field-Programmable Gate Array (FPGA) and an Microcontroller Unit (MCU). The results indicate that the designed system functions as intended, though further refinements are necessary for reliable in-flight operation.