Design And Control Strategy Research For Powertrain System Of A Novel Range Extended Electric Vehicle

Growing concerns over environment pollution, shortage of fossil fuel and security of energy supply are driving a shift from traditional vehicle to new energy vehicle, especially the electric vehicle. However the low capacity, high manufacture cost and short life cycle of battery make the electric vehicle hard for commercial development. Instead the Range Extended Electric Vehicle(REEV) can increase the driving range, reduce the vehicle emission and dependence on fossil energy without largely increase the cost. Therefore the REEV is the ideal alternative to the traditional vehicle. A new type of REEV powertrain is proposed from the point of dynamic coupling mechanism and the main details are as followed.① Search and read the relative literatures to analysis the characters of REEV and know the overseas and domestic research status.② The traditional serial powertrain scheme requires the driving motor with high peak power, and the efficiency of driving motor is reduced in low load running. Therefore a novel type of REEV powertrain is proposed to solve the problem from the point of coupling mechanism.③ The vehicle required total power is statistically analyzed based on the world standardized driving cycle. The vehicle running modes and gears are divided for the powertrain of REEV and the dynamic equations are derived according the mode of operation. Furthermore the parameters matching and modeling are carried out for the powertrain according to the design indexes.④ The shifting control strategy is formulated and the switch control strategy between single motor driving and dual motor driving is formulated. Then the engine control strategy is proposed combining the “three fixed working points” and “the optimal fuel consumption rate curve” according the battery state of charge and vehicle working load. Moreover the regenerative braking control strategy is formulated aiming at the objective of maximum braking energy recycling.⑤ The REEV simulation model is established on the platform of Matlab/Simulink.The parameters modification and simulation verification of the design parameters and control strategy are performed for the scheme of the REEV powertrain.