Development of energy management strategy for plug-in hybrid electric bus

Plug-in hybrid electric vehicles (PHEVs) have a larger battery and can replace a certain amount of conventional fossil fuels with grid electricity differing from hybrid electric vehicles (HEVs). The usage way of the onboard electrical energy significantly influences the utilization efficiency of energy and then impacts the fuel economy. In this paper, a single-axis series-parallel plug-in hybrid electric bus (PHEB) is taken as the research object and its systematic model was built for fuel economy evaluations. The PED + HDCD + HDCS strategy, which is combined with the pure electric driving (PED) mode, hybrid driving charge depleting (HDCD) mode and hybrid driving charge sustaining (HDCS) mode, is developed. Under the co-simulation platform comprised of Cruise and Matlab/Simulink, a systematic simulation experiment is performed and the results show that the PHEB fuel economy is improved more than 50% compared to the prototype bus.