A series-parallel hybrid electric vehicle control strategy including instantaneous optimization of equivalent fuel consumption

Control strategy for a series-parallel hybrid electric vehicle powertain aimed at operating the engine in its optimal fuel efficiency operating region is proposed in the paper. An instantaneous optimization algorithm based on the equivalent consumption minimization strategy (ECMS) is used in order to improve the hybrid vehicle fuel efficiency, and it is combined with a battery state-of-charge (SoC) controller to honor predefined SoC bounds. The effectiveness of the proposed control strategy is verified by means of computer simulations for three characteristic certification driving cycles.