Hydrogen-based powertrains modelling for passenger car and heavy-duty truck

The current energy crisis and climate change are driving the development of alternative solutions to reduce greenhouse gas emissions. The transport sector consumes a large amount of fossil fuels and is responsible for 24% of global carbon dioxide emissions, so car manufacturers and researchers have turned their attention to new electric fossil-fuel-free powertrains in recent decades. Fuel cell hybrid electric vehicles (FCHEVs) are gradually reaching maturity; they consist of a fuel cell and an energy storage system (ESS), usually represented by a battery, to meet the dynamic power required by the electric motor to run the vehicle. Their versatility in design based on modular structure and hydrogen storage, high efficiency and high energy density make this technology very promising for the transition to clean energy. This thesis focuses on the description of the general principles of FCHEV, its components and different powertrain architectures based on the degree of hybridisation (DOH); in addition, a sizing algorithm built on Matlab is discussed, the aim of which is to find the best DOH and the resulting fuel cell and battery size that minimises the net present cost of the system. The sizing tool can be used for the optimal sizing of any vehicle, in this thesis results are presented for two cases, a passenger car and a heavy-duty truck. There are already studies in the literature that support and verify the technical feasibility in long distance heavy applications of FCHEVs, this is further highlighted by this work in which it is shown the heavy-duty truck is more economically feasible nowadays for intensive use in terms of driving range than battery electric truck. On the other hand, for passenger cars applications, battery electric vehicles (BEVs) still remain more convenient for stop-and-run applications in urban driving conditions with limited range. Hydrogen-powered cars start to become more cost-effective than BEVs for long distances or in a future large-scale production scenario, due to the lower purchase and maintenance costs of fuel cells and hydrogen refuelling costs. Serial production and the continuous development of technology to increase the performance and durability of components as well as the parallel development of infrastructure for fast hydrogen refuelling are key aspects for the transition from niche markets to large-scale markets and for sustainable mobility transition.