Gear locking mechanism to extend the consistent power operating region of the electric motor to enhance acceleration and regenerative braking efficiency in hybrid electric vehicles

Abstract

Hybrid electric vehicle and electric vehicles are employing electric motor as one of the major propulsion medium. As a result of the higher performance requirement and to manipulate the variety of driving circumstances, sizing of the electric motor is crucial in this particular drivetrain systems. In addition to that, since the electric motor is assisting with the IC engine to achieve the acceleration demand in the parallel hybrid electric vehicle, the motor sizing is critical here. Moreover, regenerative braking performance is important for the energy enhancement of the vehicle. However over sizing the electric motor will cause to the other issues such as over sizing the power converter, battery system, power electronic design, etc, which is unfavorably increasing the weight and volume of the vehicle. Therefore a novel gear shifting mechanism is introduced here to achieve the expected performance output from a low power output motor. Optimum operating efficiency of the electric propulsion system is achieved by extending the constant power operating region of the electric motor generator in the vehicle.