Fuel cell plug-in hybrid electric vehicle thermal management strategy in parking time for low-temperature environments

This work presents a thermal management strategy for fuel cell hybrid electric vehicles under low-temperature conditions. Protecting the fuel cell system (FCS) and battery pack from such operating conditions prevent their degradation and performance decay. Thus, an approach similar to the keep-warm strategy is proposed to avoid the well-known issues related to the thaw-at-start methods, as well as promote a rapid startup after long parking periods. Particularly, the present work proposes a strategic synergy between the battery pack recharging and thermal management during the parking phase, so as to minimize the fuel consumption, while featuring vehicle to grid functionality and rapid startup of the vehicle when resuming driving. Such thermal management strategy was evaluated via simulation analyses, considering the transient thermal dynamics of the FCS and battery pack under low-temperature conditions and the temperature control strategy. The results outlined how proper exploitation of plugin functionalities, beyond introducing innovative vehicle-to-grid (V2G) concepts to suitably link driving to parking phases energy management, also allows for low-temperature safe thermal management of involved electrochemical devices. Finally, an economic analysis demonstrated that the proposed plugin-based vehicle to grid scenario presents a cost-saving potential of up to 56 % with respect to non V2G charge-sustaining one.