Research on Torque Control Distribution between Motor and Engine in P2.5 Hybrid Vehicle

Abstract

The normal torque distribution of the P2.5 hybrid system is based on the strategy of open-loop engine control, dynamic engine torque estimation and the motor torque compensation. To meet the rapid acceleration and the deceleration, the motor torque is compensated according to the estimated engine torque to satisfy the driver torque request first, and then satisfy the battery charge torque. Other torque distribution strategies are defined according to the special working conditions below:1) To improve the efficiency of the engine and the response of the system and to avoid the drop of engine speed, the motor compensation enabled condition and torque distribution strategy is defined.2) To enhance the performance of fuel consumption and emission during the catalyst heat phase, the catalyst heat phase is divided into two phases and the torque distribution strategy is defined. 3) To decrease the battery heat time and extend the battery health life, the battery heat enabled condition and torque distribution are defined. The vehicle results are conducted and show that the normal torque distribution control can meet the acceleration and deceleration goal and drivability performance. The motor compensation can meet the driver torque by the motor and avoid the drop of the engine speed. The control of the catalyst heat phase can do good to the emission and fuel consumption.