Optimal energy management in fuel cell light commercial vehicles towards aging-reduced operation for different degrees of hybridization

This paper investigates the energy management in fuel cell light commercial vehicles (FC-LCV) towards aging-reduced operation. The study employs multidimensional dynamic programming (DP) to reduce H2 consumption and fuel cell (FC) degradation. The proposed method offers offline benchmark solutions for the development of online-capable operation strategies. At the vehicle-level, both the power split between the fuel cell system (FCS) and the hybridization battery, as well as the thermal management of the fuel cell stack, are considered. Key physical operating parameters of the FCS, such as voltage and stack temperature are integrated into the optimization of the energy management strategy to effectively address FC degradation. In order to gain a comprehensive overview, various weighting factors in the cost function, degrees of hybridization, driving cycles and states of health (SoH) of the FC are evaluated. This study examines three realistic LCV use cases in addition to standard driving cycles. The weighting between H2 consumption and FC degradation is analyzed to gain further insights into aging-reduced operation. Finally, the optimal Pareto fronts obtained from the optimization are compared with one another and with online-capable operation strategies for reference. The comparison indicates that PHEV with larger batteries tend to lower degradation factors, due to the pronounced loadshift of the FCS and charge-depleting mode of the battery. By adjusting the weighting to reduce FC aging, degradation factors for the PHEV with a 60 kW FCS are ∼10.2% lower compared to the sHEV with a 100 kW FCS, and ∼16.7% lower compared to the sHEV with a 140 kW FCS, respectively. The sHEV with a 140 kW FCS achieves ∼2.6% lower H2 consumption compared to the sHEV with a 100 kW FCS, due to higher efficiencies at the same loads. While more demanding driving cycles result in higher H2 consumption, they simultaneously exhibit lower degradation factors compared to less demanding cycles due to reduced FC voltage levels. The article concludes with an outlook on future studies in this research area. •Benchmarking method for online operation strategies in FC light commercial vehicles.•Global optimization of consumption and FC aging considering voltage and temperature.•Analysis of weighting factor, degrees of hybridization, driving cycles, and FC SoH.•Larger battery capacities hold more potential to mitigate FC aging than smaller ones.