Hierarchical energy management strategy based on the maximum efficiency range for a multi-stack fuel cell hybrid power system

Estrategia jerárquica de gestión de la energía basada en el rango de máxima eficiencia para un sistema de alimentación híbrido de pilas de combustible multi-pila

Abstract

A multi-stack fuel cell hybrid power system (MFCHS) con

sists of multiple sources with various characteristics. The power

distribution between different sources influences the perfor

mance of the system, which involves many factors. To distrib

ute the power effectively and enhance the efficiency and fuel

economy of a single-stack fuel cell system, this study proposed

a hierarchical energy management strategy (EMS) for MFCHS.

An MFCHS configuration that included three fuel cell systems

and a battery was presented. An MFCHS model that incorporated

the effect of altitude was constructed, and an efficiency analysis

of the multi-stack fuel cell system (MFCS) was performed. The

hierarchical EMS of MFCHS was composed of a bottom control

layer and a top management layer. The bottom control layer uti

lized a coordinated optimal distribution strategy based on the

maximum efficiency range of MFCS to realize optimal power al

location between the different fuel cells in MFCS. The top man

agement layer used EMS under multiple operating conditions to

realize the effective distribution of the demand power between

MFCS and the battery. Results demonstrate that the proposed

strategy improves the average efficiency of MFCS by up to 5.2%

and 8.9% compared with those of the equal distribution and

daisy chain strategies, respectively. The proposed strategy also

displays good performance in terms of the hydrogen consump

tion of MFCS, which saved 1% and 3% hydrogen compared with

the equal distribution and daisy chain strategies, respectively.

The proposed strategy results in promising improvements in the

overall performance of the system. This study provides a good

reference for developing EMS for MFCHS.