Control And Simulation Analysis Of Electric Vehicle With Hub-motors

Since EV (Electric Vehicle) is a vehicle with zero or nearly zero emission, and as the problem of environment protection and resource has been receiving more and more attention, there is a trend of EV's rapid development. It is possible to take resource, environment protection and transportation into consideration during the development of EV. The hub-motor has simple and compact structure, occupies small space and is easy to realize all-wheel drive, which has been used in many fields. Rear wheels driving EV and its powertrain are studied in this thesis, respectively.This thesis establishes mathematics modeling for asynchronous motor used in an EV, vector control system is analyzed. Voltage vector controller is proposed and the algorithm of space vector pulse width modulation (SVPWM) inverter is used.The EV in forward and four-degree-of-freedom steering operation is modeled. To improve the handling characteristics when turning, a control strategy, that controls the internal and external wheels to offer equal tractive force while turning is proposed. In the control strategy the slip ratio of driving wheel is limited to optimum value.Applying MATLAB/ Simulink software to model and simulation analysis, the simulation result shows the vector control system realizes the real-time control of the asynchronous motor torque. Its speed regulation system can offer the dynamic response capability that the developed EV requires. With the control strategy on the basis of slip ratio limitation, handing characteristics of the hub-motor EV is improved.