The development of energy management strategy (EMS), which considers how power is distributed between the battery and ultracapacitor, can reduce the electric vehicle’s power consumption and slow down battery degradation. Therefore, the purpose of this paper is to develop an EMS for hybrid energy storage electric vehicles based on Pontryagin’s minimums principle (PMP) considering battery degradation. To verify the EMS, the hybrid energy storage electric vehicle model is first established. In the meantime, the battery cycle life trials are finished in order to develop a battery degradation model. Following that, a rule-based control approach and the PMP optimization algorithm are used to allocate power in a hybrid energy storage system (HESS) in a reasonable manner. Finally, a simulation experiment under urban dynamometer driving schedule (UDDS) settings verifies the established EMS, and the findings reveal that the suggested EMS has a lower energy consumption rate and battery deterioration rate than the rule-based method.

No abstract

As an auxiliary component with the largest energy consumption in the fuel cell power system, the electric air compressor is of great significance to improve the overall efficiency of the system by reducing its power consumption under the premise of meeting the cathode intake demand. In this paper, the flow state of the gas in the flow field of the fuel cell TSEAC (two-stage electric air compressor) is analyzed by simulation, and the accuracy of the simulation results is verified by experiments. Through the research on the gas compression work of the fuel cell TSEAC, it is found that the higher temperature rise of the gas during the compression process will increase the compression work, thereby reducing the efficiency of the fuel cell TSEAC. Therefore, based on the field synergy theory, this paper designs the heat dissipation structure of the TSEAC elbow. In the common working conditions of fuel cell TSEAC, micro-fin tube is an effective energy-saving structure that takes into account heat dissipation enhancement and flow resistance, and its ratio of micro-fin height to laminar bottom layer thickness ε/δ = 1.6 has the best energy-saving effect. Finally, the energy-saving effect of the micro-fin tube is verified by simulation. The load torque of the optimized fuel cell TSEAC is reduced from 1.540 N·m to 1.509 N·m, and the shaft power is reduced from 14.51 kW to 14.22 kW. Its efficiency increased by 1.9%.

Hydrogen has the physical and chemical characteristics of being flammable, explosive and prone to leakage, and its safety is the main issue faced by the promotion of hydrogen as an energy source. The most common scene in vehicle application is the longitudinal wind generated by driving, and the original position of hydrogen concentration sensors (HCSs) did not consider the influence of longitudinal wind on the hydrogen leakage trajectory. In this paper, the computational fluid dynamics (CFD) software STAR CCM 2021.1 is used to simulate the hydrogen leakage and diffusion trajectories of fuel cell vehicles (FCVs) at five different leakage locations the longitudinal wind speeds of 0 km/h, 37.18 km/h and 114 km/h, and it is concluded that longitudinal wind prolongs the diffusion time of hydrogen to the headspace and reduces the coverage area of hydrogen in the headspace with a decrease of 81.35%. In order to achieve a good detection effect of fuel cell vehicles within the longitudinal wind scene, based on the simulated hydrogen concentration–time matrix, the scene clustering method based on vector similarity evaluation was used to reduce the leakage scene set by 33%. Then, the layout position of HCSs was optimized according to the proposed multi-scene full coverage response time minimization model, and the response time was reduced from 5 s to 1 s.