The effect of battery temperature on total fuel consumption of fuel cell hybrid vehicles

In order to consider the effect of battery temperature on the total fuel consumption when a Pontryaginʹs Minimum Principle (PMP)-based power management strategy is applied to a fuel cell hybrid vehicle (FCHV), this paper designates the battery temperature as a second-state variable other than the battery state of charge (SOC) and defines a new costate for the battery temperature in the control problem. The PMP-based power management strategy is implemented in a computer simulation and the relationship among the final values of the two state variables and the total fuel consumption is illustrated based on the simulation results. This relationship is defined as an optimal surface in this research. Using the optimal surface, it can be concluded that considering the battery temperature effect in the PMP-based power management strategy improves the fuel economy of the FCHV. Potential fuel economy gains attributed to consideration of the battery temperature effect are also determined based on the optimal surfaces.