The use of fuel cells in DC microgrids has been receiving a lot of attention from researchers and industry since both technologies can deliver clean energy with little to no environmental impact. To effectively integrate fuel cells in DC microgrids, a power converter that can equate the fuel cell’s voltage with the DC microgrid’s reference voltage is required. Based on the typical output voltages of fuel cells, buck-boost topologies are commonly used in this type of application. A variety of DC-DC buck-boost topologies, showing distinctive merits and drawbacks, are available in the literature. Therefore, this paper compiles, compares and describes different DC-DC buck-boost topologies that have been introduced in the literature over the past few years. Additionally, some design considerations are addressed, and future work is proposed.

The complexity of Fuel Cell (FC) systems demands a profound and sustained understanding of the various phenomena occurring inside of it. Thus far, FCs, especially Proton Exchange Membrane Fuel Cells (PEMFCs), have been recognized as being among the most promising technologies for reducing Green House Gas (GHG) emissions because they can convert the chemical energy bonded to hydrogen and oxygen into electricity and heat. However, their efficiency remains limited. To enhance their efficiency, two distinct factors are suggested. First, the quality of materials plays a significant role in the development of more robust and efficient FCs. Second, the ability to identify, mitigate, and reduce the occurrence of faults through the use of robust control algorithms is crucial. Therefore, more focused on the second point, this paper compiles, distinguishes, and analyzes several publications from the past 25 years related to faults and their diagnostic techniques in FCs. Furthermore, the paper presents various schemes outlining different symptoms, their causes, and corresponding fault algorithms.