Powertrain Parameters Matching And Simulation Research Of ISG Mild Hybrid Electrical Vehicle

As the stress of oil source scarcity and deterioration of urban environment become more and more severe , it is urgent to seek a new technology of saving energy and reducing the exhaust emission. Electric vehicle (EV) seems to be the best method to solve these problems, but its development is currently limited by battery's low energy density . Fuel cell electrical vehicle(FCEV) is just on the laboratory level. On this occasion , hybrid electric vehicle (HEV) which have the merits of EV and conventional vehicle(CV) is invented, HEV investigations on become a new hotspot in international automobile field. HEV is regarded as one of the most realistic method to improve urban environment and relieve the stress of oil source scarcity.Based on the theoretical analysis, the options of HEV Powertrain Schedule and Powertrain components are discussed in this thesis. As a conclusion, integrated starter/generator mild HEV(ISG-MHV) which is suitable to mini car is put forward. The control strategy of idle-stop, cruise, accelerate, and decelerate are discussed. Then, the working modes of idle-stop, power assist, engine drive lonely, power regeneration, friction brake are anslysed. In addition, some simulink modules of ADVISOR are modified according to the Powertrain Schedule , control strategy and working mode of ISG-MHV in this thesis. Based on theoretical analysis and relative reference, the parameters designing method of the ISG-MHV powertrain components including ISG, engine, battery and gearbox are presented. At the same time, the parameter matching analysis is given according to the design requirement of ISG-MHV and the gear ratio of transmission is optimized by the quadrature method. Then, The dynamic performance and fuel economy on the ECE+EUDC, UDDS, FTP and HWFET driving cycle are simulated by ADVISOR software. Compared with the conventional vehicle(CV) of similar dynamic performance, the fuel economy of the ISG-MHV increase above 15%, which prove the merit of ISG-MHV on fuel economy. In the end, the effect of coefficient of aerodynamic drag,rolling resistance coefficient and efficiency of powertrain on fuel economy are analysed.