Optimal Supervisory Control Strategy for a Transmission-Mounted Electric Drive Hybrid Electric Vehicle

This paper proposes a novel supervisory control for a parallel hybrid electric vehicles (HEVs) with a transmission-mounted electric drive (TMED). The proposed control includes an optimal power distribution algorithm that uses a modified equivalent consumption minimization strategy (ECMS) and an optimal mode determination algorithm based on the state machine framework. The control vector of the proposed ECMS is expanded to two degrees of freedom to determine the power-split ratios of the TMED HEV, and the cost function is re-defined in accordance with the target system. A new mode-transition algorithm is also proposed to prevent the occurrence of frequent mode transitions as well as improve fuel economy and drivability. Simulation results demonstrate the validity and performance of the proposed control algorithms.