Design Of Energy Management Strategy For Hybrid Railway Based On Comprehensive Efficiency Optimization

In recent years,the proportion of rail transit in the entire transportation industry in various countries has been increasing and the proportion of fuel consumption has continued to increase.In order to develop energy-saving and environmentally friendly rail transit,new energy trains are becoming more and more popular.In this paper,a gasoline-electric hybrid railway is designed,and the hybrid coupling mechanism and the energy management strategy based on comprehensive efficiency optimization are introduced in detail.The main contents are as follows:(1)According to the connection characteristics of the single planetary row,two power split configurations,input distribution type and output distribution type,were selected,and then two types of input power split were selected by analyzing the selection range of the transmission ratio and the ratio of electrical power to mechanical power.a configuration scheme.According to the above two configuration schemes,the power components and power switching components are arranged,and the hybrid coupling mechanism scheme that meets the design requirements is designed and selected with the power performance,space size and working mode as the evaluation indicators.(2)According to the test data calibrated by the bench test,the map of the working characteristics of the engine and the motor is obtained,and the modeling process of the battery,the calculation method of the SOC,the longitudinal dynamics calculation of the train and the construction of the vehicle simulation model are introduced.The method provides the basis for the modeling and simulation calculation in the following.(3)According to the characteristics of trains that determine the running route,an energy management strategy based on comprehensive efficiency optimization is adopted.Firstly,the calculation methods of the comprehensive efficiency and constraint conditions of each driving mode are introduced,and then the optimal efficiency control variable combination and the feasible region of train operation are obtained through the backward simulation calculation,and the mode switching rules to ensure the optimal comprehensive efficiency are determined.Based on the calculation results of the backward simulation,the power distribution strategy of each driving mode is introduced,and the energy management control strategy scheme of the train in each running state is designed to ensure the fuel economy and SOC balance,and the output torque of each power component is controlled by PI.Coordinate control is carried out to ensure that the train can follow the target speed according to the target torque.(4)Matlab/Simulink software is used to build forward simulation models of hybrid train and fuel railway.By analyzing the ability of the two models to follow the target speed track,it is found that the hybrid train has higher power performance.By comparing the fuel consumption and effective fuel consumption of the two models,it is proved that the fuel economy of hybrid train is significantly higher than that of internal combustion engine train.In addition,it is proved that the energy management strategy based on comprehensive efficiency optimization can effectively keep The SOC balance and make the engine work within the economic range through the SOC state trajectory and the distribution of the working points of the engine and the motor.