Study on the economic and environmental benefits of different EV powertrain topologies

Numerous feasible schemes of powertrain topology can be designed for the electric vehicles (EVs) based on the distributed configurations of the electric motors. In this study, the effects of different EV powertrain topologies on the energy efficiency, vehicle ownership cost and lifecycle greenhouse gas (GHG) emissions of EVs are investigated. Energy-based vehicle simulation model including the regenerative braking function and battery degradation prediction method is established firstly. An optimization scheme combining the energy-based vehicle simulation model is conducted to minimize the electric energy consumption under various scenarios and driving conditions. Then the vehicle ownership cost and lifecycle GHG emissions of EVs are evaluated based on Chinese EV market and electricity grid. The sensitivity analyses of EV powertrain topology are implemented based on the different vehicle weights, CO2 intensities of electricity and all-electric ranges. Results show that EVs using the powertrain of wheel-hub drive with the gear reducer have lower energy consumption. Furthermore, the driving cycles with more aggressive acceleration/deceleration and frequently stop-and-go conditions can increase both the vehicle ownership cost and lifecycle GHG emissions simultaneously. Chinese city traffic conditions will help EVs to obtain more benefits in respect of the economy and environment.