Fuel cell/supercapacitor hybrid power systems for UAVs: A comprehensive review of technologies, architectures, and energy management strategies

Unmanned Aerial Vehicles (UAVs) have become indispensable across various sectors, demanding efficient and reliable power solutions to extend flight endurance and enhance operational performance. Traditional battery-based power systems face several limitations, including weight constraints and slow recharge times. Hydrogen Fuel cells (FCs) have emerged as a promising alternative to batteries due to their higher energy density and potential for extended flight endurance. However, the inherent limitations of using FCs alone, such as slow dynamic response and low power density, have driven a shift toward hybrid energy solutions that combine FCs with complementary technologies. Among these, fuel cell/supercapacitor (FC/SC) hybrid power systems have emerged as a reliable alternative, combining the high energy density of FCs with the rapid power response of supercapacitors (SCs). This paper presents a comprehensive review of FC/SC hybrid power systems in UAV applications, analyzing their power supply architectures, operational benefits, and energy management strategies (EMS). The study primarily highlights the existing research gaps in the development of FC/SC systems for UAVs, while illustrating their advantages over conventional power sources and alternative hybrid architectures across key performance parameters. Furthermore, various EMSs, including conventional rule-based methods, optimization techniques, and data-driven approaches, are critically examined for their role in enhancing UAV system efficiency and operational reliability. The review further explores advancements in hybrid architectures that optimize power distribution between FCs and SCs. By reviewing existing research gaps and evaluating the practical implications of FC/SC hybrids, this study provides insights into the future development of energy-efficient UAV power systems capable of meeting the increasing demands for extended flight duration, rapid responsiveness, and sustainable operation.