Minghui Liu

Study on New Concept Powertrain for Range-Extended Electric Vehicles

Range Extended Electric Vehicle (REEV) can extend driving range of EV by engine when battery SOC reaches its lower limit. But usual REEV powertrain is serial, fuel consumption of which is high in high speed driving condition when vehicle works in Range Extended mode. With the problem, a new concept powertrain for REEV is presented in this paper. It has better driving condition adaption, as it can work in serial or in parallel according to driving condition. Firstly, the configuration of new Range-Extended Electric Vehicle powertrain is proposed, which contains engine, BSG motor, clutch, traction motor and two-speed DCT. In Range Extended mode, it can work in serial or parallel. Two-speed DCT can adjust operating points of engine and traction motor. In addition, engine, BSG motor and traction motor can be downsized due to the use of clutch and DCT. Secondly, component parameters are designed according to vehicle requirements. Thirdly, control strategy of REEV based on the new concept powertrain is designed. Moreover, detail design for an A0 car is presented, and advantages of the new concept powertrain are evaluated by simulation. Evaluated by simulation, the new concept powertrain can meet requirements of Range Extended Electric Vehicle, and fuel economy of new concept powertrain is good in various driving cycles when vehicle works in Range Extended mode.