Study on Energy Management Strategies for Series-parallel Plug-in Hybrid Electric Buses

The power flow between the power sources and the performance of plug-in-hybrid electric vehicles (PHEV) significantly in fuel economy are mainly determined by energy management strategy. To research the energy management of the PHEV, the control strategy of a plug-in series-parallel hybrid electric bus (PHEB) is studied in this paper. Firstly, the simulation model of the PHEB is built with CRUISE software. Secondly, to explore the fuel-saving potential of the PHEB, the global optimal control strategy which adopts dynamic programming (DP) algorithm is studied and built with MATLAB software, although the minimum fuel consumption of certain driving cycle can be a benchmark for evaluating the energy management strategy of PHEB, the global optimal control strategy based on DP is rarely directly applied in real vehicle due to its long online computation time. At last, to ensure control timely, a rule-based control strategy is calibrated according to the computation results of global optimal control strategy. The simulation results show that, the fuel consumption per 100 km decreased by 9.11% and the electric power consumption per 100 km decreased by 6.27%.