Overall Design And Dynamic Parameter Matching And Optimization Of A Miniature Electric Electric Car

For the growing energy crisis and its ineradicable emission problem, people begin to pay attention to pure electric vehicle, though traditional automobile technology is well developed,. Compared with internal combustion engine cars, pure electric vehicle has series of advantages, such as high efficiency, emission-free and noise-free; it is a good way to work out the problems of energy and pollution. In the research and development of electric vehicle, it is important to match key components and its parameters reasonably and choose the driving form scientifically, which are very crucial to improve the overall performance of the car.In this paper, a micro-pure electrical car is taken as the research object, firstly, the basic composition and working principle of it are analyzed, and the power train and energy system are described emphatically. This paper also discusses the development and application of vehicle motor and battery, which are chosen on the basis of it; summaries the mainstream form of vehicle drive system, designs the three dimension modeling of the car, according to its market position and overall layout requirements.Then, this paper calculates the required power of the motor under certain conditions, according to the basic parameters and dynamic performance of the vehicle, and determines all the parameters of motor with the calculation results, calculates the capacity of the battery pack and determines the other parameters of it according to the driving mileage. After that, the gear ratio of the transmission system is calculated, and two transmission schemes are designed, that are two gears and fixed gear transmission, for which each gear ratio is roughing selected.After the completion of the parameters matching, the simulation model of the motor, battery pack, transmission and so on is built by the use of the vehicle simulation software ADVISOR, and all the models are connected,and the whole vehicle simulation models is established. Using this model, the simulation test of the dynamic performance and economic performance of the matched vehicle are simulated and tested, test results show that the established simulation model and the matched parameters are reasonable and effective. At the same time,some factors which affect the dynamic performance and economic performance of the electric vehicle are simulated and analyzed,which provides a direction for improving the overall performance of the EV.Finally, the transmission ratio is optimized under the condition that the parameters of the motor and the battery are constant. The optimization method of the fixed gear transmission scheme is interval optimization, which not only reduces the workload, but also ensures the reliability of the optimization. After optimization, the car climbing capacity increased by 2.5%, the maximum speed increased by 5.7%; Mileage of ECE EUDC conditions and 60km/h uniform conditions have been significantly improved, the amplitude were 4.9% and 6.1%; for the two gear transmission scheme, the method is fitting function optimization, and the genetic algorithm in the MATLAB optimization toolbox is used for optimization calculation. According to the optimized results, the performance of the vehicle is compared with the simulation, the simulation results show that after optimization, the maximum speed increased obviously, by 12.5%, the mileage of ECE_EUDC condition and 60km/h uniform condition have been significantly improved, the amplitude were 5.5% and 2.3%. After the optimization, the two schemes are compared. The advantages and disadvantages of the two schemes are discussed, and then the fixed gear transmission scheme is selected for the EV.