Strategy for increasing hybrid electric vehicle reversibility

To achieve a low fuel consumption, the basic approach requires a minimum fuel consumption of the vehicle at steady speed which can be obtained by an efficient internal combustion engine with a low vehicle weight and size, small aerodynamic drag, and low tire rolling resistance. This steady speed fuel consumption can further be improved by using a smaller engine operating at its most efficient operating range. However, this would need an auxiliary electric motor to power assist the vehicle in acceleration and hill climbing. The next step in improving fuel consumption is the recycling of the vehicle kinetic energy during deceleration to electric energy stored in batteries. The electric motor/generator should be capable of converting the maximum kinetic energy to electric current at the rate required and, the battery pack should also be capable of absorbing the maximum of the electric current produced by the generator at the rate required.