A two-layer control strategy for hydrogen-battery hybrid system considering the efficiency characteristics of MS-PEMFC.

■ By establishing a complete mathematical model, the efficiency characteristics of MS-PEMFC, auxiliary equipment, and converter are analyzed to clarify the relationship between output power and operating efficiency. ■ By calculating the optimal allocation mapping set and embedding it into the control system, the real-time optimal power allocation in MS-PEMFC is realized. ■ The coordinated operation strategy between MS-PEMFC and battery is proposed under light load and overload conditions. ■ Based on the complementation of transient and steady-state energy between MS-PEMFC and battery, a coordinated control between MS-PEMFC and battery is proposed to suppress the DC bus voltage fluctuation. Then, the stable operation of the hybrid system can be well ensured. The traditional control strategy for hydrogen-battery hybrid system is challenging to achieve an efficient operation in the entire power area and suppress transient DC bus voltage fluctuation. Therefore, a two-layer control strategy for hydrogen-battery hybrid system considering the efficiency characteristics of MS-PEMFC (multi-stack proton exchange membrane fuel cell) is proposed, including system optimization allocation layer and equipment coordination control layer. In terms of the system layer, the proposed optimal operation strategy can optimize the power allocation and avoid the light load condition operation of MS-PEMFC to improve the system economy. In terms of the equipment layer, the proposed coordination control between MS-PEMFC and battery can realize the transient and steady-state energy complementarity, and suppress the DC bus voltage fluctuation to improve the system stability. Finally, the feasibility and effectiveness of the proposed two-layer control strategy for hybrid system are verified by simulation and experimental results. [ABSTRACT FROM AUTHOR]