Eco-efficiency methodology of Hybrid Electric Vehicle based on multidisciplinary multi-objective optimization

The eco-efficiency concept of clean propulsion vehicles aims at is simultaneously reducing the fuel consumption and environment pollutants impact (Eco-score) without decreasing the vehicle performances and other user satisfaction criteria. Based on a simulation model in ADVISOR, one can evaluate the performances, the emissions and then the Ecoscore and the User Satisfaction for different driving scenarios. To establish a rationale methodology for conducting the eco-efficiency design of electric and hybrid vehicles, we adopt a multidisciplinary optimization approach while minimizing / maximizing both Ecoscore and User satisfaction objective functions. The proposed approach is then illustrated on the case study of the comparison of different mild parallel hybrid buses (hybrid electric vehicle (HEV) and hybrid hydraulic vehicle (HHV) by highlighting the effect of different energy storage systems (batteries, ultra capacitors, hydraulic system), mechanical and electric components sizes upon the optimized hybrid design. The optimization results show that the hybrid electric buses using ultra capacitors have almost the
same performances as those using batteries, while the HHV technology can compete with HEV because of the hydraulic components low cost and recyclability if possibly using of water as motor/pump fluid.