Establishment of energy management strategy of 50 kW PEMFC hybrid system

Abstract

A 50 kW class PEMFC and battery model were evaluated to find appropriate battery capacity for 50 kW class vehicles. Afterwards, fuel cell and battery EMS strategies were established in response to rapid load changes. First, a 50 kW class PEMFC model and a battery model were designed and verified using the experimental values. After that, the amount of SOC change according to the battery capacity was compared at the same fuel cell output: it was found that the use of a battery with a capacity of “40 kWh” or more is effective. By comparing stack and battery power, hydrogen consumption, and battery SOC according to load changes, it was confirmed that high efficiency of stack net power is not always good thing. In addition, it was confirmed that the most effective strategy is to set the fuel cell-to-battery ratio at 6:4 initially, at 8:2 when the load increases rapidly, and at 4:6 when the load decreases rapidly.

Keywords

• Proton exchange membrane fuel cell
• Energy management system
• Stack temperature
• Load change