Energy Conversion Efficiency of Hybrid Electric Heavy-duty Vehicles

Energy conversion efficiency of parallel and series HEVs was analyzed by combined analytical and simulation approach. Combined approach enables evaluation of energy losses on different energy paths and provides their impact on the fuel economy. The paper quantifies influences of different HEV topologies, power ratios and characteristics of the components, and applied control strategies on the energy conversion efficiency of HEVs. Moreover, the paper reveals characteristics of drive cycles that make possible significant fuel economy enhancement of HEVs. Additionally, impact of drive-away and vehicle propulsion by electric motor at low powertrain loads on the energy conversion efficiency of HEVs is analyzed.