Hybrid energy management system and topology of fuel cell-based electric vehicles: Key problems, progress, and future prospects

Fuel cell hybrid electric vehicles (FCHEVs) are getting exclusive attention for making transportation more environmentally friendly because they don't emit any pollutants from their tailpipes. FCHEV offers superior energy density and rapid refueling capabilities, making them more suitable for extended driving ranges compared to battery electric vehicles (BEVs). This is due to the hybrid energy system (HES) utilized by FCHEV, which incorporates both batteries and fuel cells. This study investigates the different HES topologies along with their energy management system (EMS) to ensure optimum performance and efficiency by examine of 311 research articles. Discussion is initiated with research gap to promote FCHEVs and EMS. Next, key challenges associated with FCHEVs such as: (i) cost and durability, (ii) EMS complexity, (iii) hybrid energy system (HES), (iv) safety and reliability, (v) optimization and real-time control, (vi) scalability and application diversity are explored. Different hybrid topologies consisting of battery, fuel cell, and ultracapacitor along with their comparison are analysed. Recent intelligent EMS techniques such as rule-based, optimization-based and learning-based are examined to enhance the performance, efficiency and reliability of different hybrid energy topology. Merits and demerits associated with various EMS techniques employed in FCHEV are explored.