Development of efficiency based mode control algorithm for plug-in hybrid electric vehicle

For a plug-in hybrid electric vehicle (PHEV) which consists of power-split type transmission, multiple drive modes is required to manage the PHEV to satisfy different driving situations: charge depleting (CD) or charge sustaining (CS). In this study, a transmission efficiency based mode control algorithm was proposed to determine the CD mode shift map of PHEV. The powertrain model and energy management strategy were developed. The system efficiency of PHEV drive mode was calculated based on the transmission efficiency. The efficiency map of CD mode was analyzed to derive the mode shift map for CD mode. Simulation results were compared with the experiment results to validate the proposed mode control algorithm.