Development of a comprehensive transient fuel cell-battery hybrid system model and rule-based energy management strategy

Abstract

ABSTRACT In the study, a comprehensive transient fuel cell-battery hybrid power system model is established to explore the output performances and dynamic responses of fuel cell electric vehicles (FCEVs). A fuel cell system sub-model, a one-dimensional transient Li-ion battery sub-model, two direct current/direct current (DC/DC) sub-models as well as a vehicle load sub-model are integrated. The coupled heat and mass transfer processes are considered inside fuel cell system and Li-ion battery. After rigorous model validation, the overall performances under several typical China standard vehicle road conditions are investigated, including power distribution between different power units, battery state of charge (SOC), battery charge/discharge rate, fuel cell operating duration, temperature, and other key parameters. During the 100 km h−1 acceleration processes under the preliminary rule-based energy management strategy (EMS), the accelerated speed is found to be the largest in the beginning, resulting in the fact that the discharge power for battery increases sharply. The shorter the acceleration time, the larger the maximum power demand for Li-ion battery. During the combined 1300 s high-speed operating conditions under the on-off switch EMS, the total operating duration of fuel cell system is calculated to be about 531 s, and the total output power is calculated to be 11,556 kJ. In comparison, the vehicle saves about 1044 kJ energy and increases the fuel cell operation duration by 333.7% under the power-following EMS. The present study provides important guidance in terms of dynamic simulation analysis and energy management strategy for FCEVs.