Smart accelerating and braking achieving higher energy efficiencies in electric vehicles

Efficient operation of EVs is critical to optimise the usage of their relative small energy storage. Although each motor controller has a unique range of motor rotational speeds (rpm) and loads for optimal efficiency, EVs lack variable gearboxes that can match vehicle speed and motor rpm to efficient controller regions. EVs thus rely on the driver to actively influence the load by changing acceleration or deceleration rates for a more efficient operation. Despite this, most EV efficiency studies use speed profiles with small changes in acceleration and deceleration rates. This study investigates the impact of various high load variations in accelerations and decelerations on energy consumption. The results show significant improvements in efficiency and reduced energy consumption by applying high loads at low vehicle speeds and strong deceleration rates. However, the increased losses under certain high acceleration rates outweighed the benefits of loading an EV. © 2018 Inderscience Enterprises Ltd.