Matching And Simulation For The Powertrain Of Electric Vehicle

Because of the rapid development of automobile industry, the environmental pollution and energy shortage problem have become a problem which we have to face and solve urgently, Pure electric vehicles with green environmental protection, low noise, etc, has become the focus of the development of modern automobile industry. In recent years, how to effectively develop the electric car market has become a current research hot spot, many countries and related enterprises have invested a lot in the field.But the key technology of the electric car has not been well solved, especially the driving range of EV is short and battery charging time is long, so before the battery technology is solved, under the same conditions of the performance of battery, how to make the transmission system to achieve the optimal performance, thus improve the dynamic performance of motor vehicles and limited driving distance, is the focus of this article research.This paper takes the electric vehicle power system as object, calculates the peak power of the motor, rated power,the peak speed of the motor, rated speed of the motor according to the maximum speed,the maximum gradeability and the maximum acceleration performance; this paper adds the transmission device due to the limitations of the motor torque range, calculates the minimum transmission ratio based on the maximum speed, calculates the maximum transmission ratio based on maximum gradeability, calculates the number of stalls with formula; calculates the number of battery and the capacity of battery according to the maximum output power and the driving range.This paper analyses the working principle and characteristics of the motor and builds the model based on ADVISOR; analyses the working principle and characteristics of the power battery and establishes the model; studies for the shift schedule of pure electric vehicles, builds the model according to the dynamic shift schedule; studies for the principle of electric vehicle’s regenerative braking, builds model according to the best braking energy recovery; analyses and simulates the electric vehicle power (maximum speed, maximum climbable gradient,acceleration time)and economic (driving range).This paper designs the optimization variables, the objective functions and the constraints according to the really instance, then makes the simplified approximation model by DOE in Isight, pure electric vehicle drive system were optimized by using genetic algorithms, the results of analysis show that the optimized vehicle economic performance increases20.1%, maximum speed increases8.6%in comparison with the last one, and the performance of acceleration and the maximum gradeability are decline, but optimized vehicle performance is closer to designed.The result is proved the feasibility of this matching and optimization method.