| The construction of vehicle driving cycle is of great significance to the research of vehicle energy consumption,emissions and the matching of vehicle power system.For a long time,domestic research on vehicle testing and other aspects generally refers to foreign driving cycle.However,due to differences in road traffic environments,foreign driving cycle are not well applicable to my country’s vehicle research.At the same time,because pure electric bus is different from traditional vehicle in terms of structure and working principle,the driving cycle of traditional vehicle cannot be well suited for pure electric bus.According to statistics,in the field of public transportation in my country,pure electric bus account for more than 40%,so it is of great practical significance to construct pure electric bus driving cycle in a specific area.At the same time,matching the power system of a pure electric bus based on actual driving cycle can also better promote the research on the power and economy of the bus.Taking Xi’an as an example,this paper conducts a study on the construction of pure electric bus and the matching of power system,the main research contents and conclusions are as follows:1.Conducted research on road traffic conditions and pure electric bus operation conditions in Xi’an,selected bus routes to collect bus driving data,through the analysis of the data,the driving characteristics of pure electric bus in Xi’an are obtained.Compared the driving characteristics of pure electric bus during off-peak and peak periods,it is found that there are obvious differences between the two,so it is necessary to construct the driving cycle of pure electric bus during off-peak and peak periods respectively.2.Selected short trip method to construct driving cycle,extracted many short trips,and selected multiple feature variables to describe the characteristics of these short trips.Through principal component analysis and clustering algorithm,the construction of driving cycle of pure electric bus in Xi’an during peak and off-peak periods is completed.Validation of the constructed two driving cycles shows that the relative error with the actual data is relatively small,indicating that these two driving cycles are representative and can reflect the actual vehicle driving conditions.3.The power system is matched based on the two structures of single motor and dual motor respectively,the basic parameters and performance indicators of the vehicle are determined,and the parameters of the main components are calculated and selected,mainly including the design of the motor,battery,and transmission system.In the CRUISE software,the vehicle is modeled based on two structures of single motor and dual motor.Multiple simulation task settings are used to evaluate the dynamic and economy of the built model,and a variety of performance simulation results are obtained,including acceleration time,maximum speed,maximum gradeability,cruising range under specific driving cycle,etc.The simulation results show that the two structures meet the performance index requirements and each has its own advantages,the overall performance of the dual-motor structure is better than the single-motor structure. |
