An Improved Energy Management Strategy for Multi-Stack Fuel Cells Based on Hierarchical Strategy

Compared to single-stack fuel cell systems, multi-stack fuel cell systems (MFCS) can increase fault tolerance through redundancy. In this paper, an improved energy management control strategy (EMS) based on hierarchical is proposed for power allocation of fuel cells and the battery based on a multi-stack fuel cell hybrid power system. This strategy aims to maintain the state of charge (SOC) of a battery within a healthy range and reduce hydrogen consumption. At the overall level, power distribution is carried out between the battery and fuel cell; At the local level, power distribution is then applied to individual fuel cells. Fuel cell weighting factors were used and range reduction control was applied to SOC. The simulation results show that when the SOC is high, low, or within the expected range, comparing the improved state machine strategy with the traditional state machine strategy, the SOC of the improved state machine strategy changes faster to the expected range, and the hydrogen consumption is also reduced by 11.550g, 9.200g, and 9.710g, respectively. Thus, the economy and durability are improved.