Simulation Study On Performance Optimization Of Extended-Range Electric Bus Based On Multi-Island Genetic Algorithm

China is actively promoting energy conservation and emission reduction and striving to achieve carbon neutrality by 2060.Extended-range electric bus can effectively improve driving range,reduce emissions and reduce pollution.It is an ideal model for the transition from traditional internal combustion engine bus to pure electric bus,and the development of extended-range electric bus accords with the general trend of bus development in China.In this paper,the performance parameters of extended-range electric bus are optimized based on multi-island genetic algorithm.The main research contents are as follows:Firstly,according to the vehicle parameters and design indicators,the range extender,driving motor,power battery and other key components of the power system of the extended-range electric bus are selected,the parameter matching of the key parts in the powertrain system of extended-range electric bus is carried out by means of theoretical analysis.Secondly,the power following control strategy is selected as the vehicle control strategy,The range extender,driving motor,power battery and other key components of the extended-range electric bus as well as the whole vehicle are modeled by the ADVISOR simulation platform and the simulation analysis is carried out under CYC＿CHINAURBAN condition.The simulation results show that the power performance and economy of the vehicle meet the design indexes,and the rationality of its selection,parameter matching and control strategy selection is verified.Finally,based on the multi-island genetic algorithm,the vehicle performance is optimized in the Isight optimization software.The weight coefficients of optimization objectives such as the maximum speed,the maximum climbing slope,0-50km/h acceleration time and the minimum fuel consumption per 100 km in the objective function are selected.Five sets of data are selected to compare and analyze the economy and power performance of the extended-range electric bus under CYC＿CHINAURBAN and CYC＿CSHVR conditions,and then the optimal weight coefficient is determined.SOC-low,SOC-high,PE-low,PE-high and FD-ratio of main deceleration are optimized.The results show that the performance of the extended-range electric bus is improved and meets the design criteria of the bus in this paper.