Regenerative braking control for hybrid electric vehicles under decelerating condition

The operating mode of a single shaft hybrid electric vehicle (SSHEV) in which the electric motor exerts negative torque on the shaft to imitate engine braking is analyzed. The method of determining the quantity of regenerative braking torque is proposed with the premise that the braking intensity required by the driver is satisfied. On this basis, factors that affect torque generated by the motor are listed, and how the battery's temperature and state of charge (SOC) restrict and correct the braking torque is expounded. Finally, road test results show that the motor's constant power or constant torque control is an effective way to recover the mechanical energy during decelerating.