Online hierarchical energy management strategy for fuel cell based heavy-duty hybrid power systems aiming at collaborative performance enhancement

The fuel cell based heavy-duty hybrid power system has gained increasing attraction in high-power transporta-tion applications. The real-time energy management strategy is essential to the collaborative performance enhancement between fuel economy and durability for this type of heavy-duty hybrid power system with inherent performance inconsistency, which still remains a promising problem. In this paper, a hierarchical energy management strategy is proposed to comprehensively consider the coupling effect between top-level power distribution among different system clusters and bottom-level power distribution within each system cluster. It is inspired by the piece-wise quadratic equivalent modeling for the energy consumption characteristics of hybrid power system. Then, the coordinated power distribution optimization can be unified for different types of system clusters and online obtained analytically, and the quantitative correlation between the fuel economy and durability is characterized. The effectiveness and practicability of the proposed strategy are verified by three assessment cases based on the hardware-in-the-loop simulation. Detailed results demonstrate that, benefited from the accurate energy consumption characteristics modeling with less than 3% residuals within most power ranges, the collaborative performance enhancement for fuel cell based heavy-duty hybrid power system can be guaranteed by the proposed strategy. Indeed, up to 4.1% hydrogen consumption conservation with state-of-charging stability as well as robustness against life-cycle duty cycle uncertainty can be achieved compared with the other two advanced online strategies.

Automated summary

In this paper, a hierarchical energy management strategy is proposed to comprehensively consider the coupling effect between the top-level power distribution among different system clusters and the bottom-level power distribution within each system cluster. The proposed strategy guarantees the collaborative performance enhancement for fuel cell based heavy-duty hybrid power system through accurate energy consumption modeling. The effectiveness and practicability of the proposed strategy are verified by three assessment cases based on hardware-in-the-loop simulation.