Developing the energy management strategy for fuel cell-powered shunting locomotives through fuzzy logic control based Pontryagin minimum principle

Considering the hydrogen refilling and onboard storage, the fuel cell is particularly suitable for application in the shunting locomotives to achieve carbon neutrality. Shunting locomotives typically operate under frequent start–stop conditions, which increase hydrogen consumption rate as the frequently changing fuel cell power output deteriorates both electrochemical and mass transfer performance. This paper first compares the effect of Pontryagin's minimum principle control strategy (PMP), dynamic programming (DP), and the power following control strategy (PFC) on shunting locomotive fuel cell energy management. To enable the online optimization of the PMP strategy under transient conditions, fuzzy logic control (FLC) was applied to the PMP calculation to calculate the equivalence factor in real time. All models were developed using MATLAB/Simulink. Two typical shunting locomotive operating conditions were selected for comparison: the push-pull condition and the whole train pull-out condition. For evaluation, the results demonstrated that the hydrogen consumption under the PMP strategy was respectively reduced by 8.22 % and 8.82 % under the two conditions, compared with the PFC. Furthermore, by adopting the proposed FLC-PMP strategy, the hydrogen consumption decreased by an additional 3.87 % and 4.03 %, compared with the conventional PMP strategy. When benchmarked against the DP results, under the push-pull condition, the fuel economy achieved by the FCL-PMP strategy improved by 15.34 % and 4.63 % compared with PFC and PMP, respectively. Under the whole-train pull-out condition, the improvements reached 21.26 % and 6.25 %, respectively.