This article proposes a novel and robust nonlinear controller for a four-phase interleaved boost converter combined with proton exchange membrane fuel cells. The proposed controller has an inner loop based on a backstepping algorithm, which would transfer the state function of the system to the differential equation of the error variable by using a recursive procedure. The reference current is generated by a supertwisting sliding mode (STSM) algorithm in the outer loop; the sliding surface is defined by the error between the output voltage and reference voltage. The strong robustness and highly dynamic feature of the proposed controller are shown by the performance of the output voltage, source current, and settling time. Besides, the parameters of the proposed controller are tuned and then well optimized using a particle swarm optimization algorithm, and their effectiveness is verified by considering the uncertainty of different operation statuses and the deviations of circuit components. Furthermore, a double-loop STSM controller is chosen for comparison and discussion. The effectiveness of the proposed controller is further evaluated through experimental results obtained with a 500 W fuel cell system based on a real-time hardware-in-the-loop system.

Electric Vehicles (EV) significantly contribute to reducing carbon emissions and promoting sustainable transportation. Among EV technologies, hybrid energy storage systems (HESS), which combine fuel cells, power batteries, and supercapacitors, have been widely adopted to enhance energy density, power density, and system efficiency. Bidirectional DC-DC converters are pivotal in HESS, enabling efficient energy management, voltage matching, and bidirectional energy flow between storage devices and vehicle systems. This paper provides a comprehensive review of bidirectional DC-DC converter topologies for EV applications, which focuses on both non-isolated and isolated designs. Non-isolated topologies, such as Buck-Boost, Ćuk, and interleaved converters, are featured for their simplicity, efficiency, and compactness. Isolated topologies, such as dual active bridge (DAB) and push-pull converters, are featured for their high voltage gain and electrical isolation. An evaluation framework is proposed, incorporating key performance metrics such as voltage stress, current stress, power density, and switching frequency. The results highlight the strengths and limitations of various converter topologies, offering insights into their optimization for EV applications. Future research directions include integrating wide-bandgap devices, advanced control strategies, and novel topologies to address challenges such as wide voltage gain, high efficiency, and compact design. This work underscores the critical role of bidirectional DC-DC converters in advancing energy-efficient and sustainable EV technologies.

As the world shifts toward a low-carbon future, green hydrogen has emerged as a critical pillar of the energy transition. It is produced using renewable energy to power water electrolysis, and it is a clean and flexible alternative to hydrogen made from fossil fuels. However it is still hard to roll out on a large scale because of technological limits, high costs, and the need for infrastructure. This review critically analyzes current electrolysis methods, including established systems like alkaline and PEM electrolyzers, as well as newly developed concepts such as AEMWE and SOWE. It discusses how they can be used in renewable energy systems, important techno-economic and durability problems, system modeling, and grid interaction. This work clarifies both the technological potential and the practical limitations of green-hydrogen electrolyzer systems while highlighting key directions for future research and implementation.