Online adaptive equivalent consumption minimization strategy for fuel cell hybrid electric vehicle considering power sources degradation

The aim of this paper is to present an on-line adaptive equivalent consumption minimum strategy (AECMS) for fuel cell hybrid electric vehicle powered by fuel cell, battery and supercapacitor. In order to design the AECMS, an equivalent consumption minimum strategy (ECMS) without considering power sources degradation is firstly designed to decrease hydrogen consumption and degradation of power sources, which chooses fuel cell as the main power source to supply steady power, battery as the main energy storage source to buffer energy demand by vehicle and supercapacitor as the peak power supplier. A testbench is built to validate the developed ECMS. By contrastive experimental tests on ECMS, Rule Based Control Strategy (RBCS) and a Hybrid ECMS Operating mode control Strategy (HEOS) through the built test bench, hydrogen consumption of ECMS decreases 2.16% and 1.47% respectively and it also has the smoothest fuel cell current. Along with the degradation of fuel cell and battery, the charge sustenance objective of battery cannot be reached. Therefore, AECMS is finally designed to adjust equivalent factors and fuel cell dynamic current change rate along with the state of health (SOH) of fuel cell and battery, to make sure the charge sustenance of battery and prolong the lifetime of fuel cell. The method that on-line estimates their SOHs and the effects of their degradation on ECMS are also analyzed.