Energy Management Strategy for Ultracapacitors in Hybrid Electric Vehicles

Electric vehicles EV are attracting attention due to their environmentally friendly operation; they market penetration may require the installation of a large number of charging stages, which is expensive and challenging from the logistic point of view. Hybrid electric vehicles HEV, may get charged from different sources which makes a flexible operation, the combination of a fuel cell, a battery, and an ultra-capacitor represents a plausible solution, ultracapacitors provide the power density required for the acceleration, and the fuel cell provides the energy density required to have a good autonomy. This manuscript proposes a fussy-logic-based energy administration strategy for an HEV feed by a set of a fuel cell, a battery, and an ultra-capacitor. The proposed strategy controls the state of charge of the ultracapacitor, considering their superior energy storage capability. Experimental results demonstrate that the proposed strategy reduces the waste of energy by 14%. This leads to energy savings, the vehicle consumed 218 Wh per km without the proposed strategy against 192 Wh per km without it, for the same example of the driving path; the estimated fuel efficiency increased 96 to 109 miles per gallons.