Construction And Optimization Of The Electromechanical Dynamics Model Of Railway Vehicle Driven By Linear Motor

Linear metro vehicle is a complex electromagnetic mechanical system.In the actual driving process,due to the increase of vehicle mileage,dynamic performance is deteriorated with the increase of failure rate.Therefore,it is the key to study the dynamic performance of linear motor metro vehicles by effectively constructing the electromechanical dynamic model considering the electromagnetic and mechanical part of the vehicle system.In this dissertation,the electromechanical dynamic model of linear motor metro vehicle is established by energy,and the simulation and optimization analysis of the model are carried out,which provides a new idea for the construction of electromechanical dynamic model of linear motor metro vehicle system.The main work of this dissertation is as follows:(1)The types,advantages and disadvantages of driving motors used in linear motor metro vehicles are compared and analyzed.The basic structure,motor installation and working principle of linear motor metro vehicles are introduced in detail,and the stress of the whole system during normal operation of the vehicles is studied.By considering the mechanical and electromagnetic part of the vehicle system,the electromechanical dynamic model of linear motor metro vehicle system is constructed according to Lagrange-Maxwell equation and virtual displacement principle.In order to simplify the model and realize the efficient control of the vehicle driving motor,the electromechanical dynamic model of linear motor metro vehicle system under d-q shafting is obtained by coordinate transformation of the established model.(2)By analyzing the main characteristics of linear motor wheel-rail traffic lines,the simple substance point model of vehicles under different line conditions is established,and the generalized force types of vehicles under corresponding line conditions are determined by using the simple substance point model and virtual displacement principle.Then,according to the electromechanical dynamics model of the vehicle system and the rotor magnetic field oriented vector control strategy with i_d=0,the models under three kinds of line conditions are solved and simulated by MATLAB software.The research shows that the sustained electromagnetic thrust required by linear motor metro vehicles is different because of the different line operating conditions in the starting acceleration stage,and the simulation results of each operating condition are consistent with the actual operating conditions of the vehicles.(3)Taking the minimum acceleration of motor rotor as the optimization objective,some important parameters in the vehicle electromechanical dynamics model are optimized by particle swarm optimization algorithm,and the simulation results before and after optimization are compared and analyzed to verify the optimization effect.Compared with the optimization before,the fluctuation amplitude of the rotor acceleration curve of the driving motor after optimization is obviously reduced,and the running stability of the vehicle is improved.(4)Based on Japanese standard JIS E4501,the strength of the optimized hollow axle is calculated considering the horizontal load P caused by vibration when the vehicle is running.Then,based on Japanese standard JIS E4502-1,the strength calculation results of hollow axle are judged,and the rationality of the optimization results of relevant parameters of vehicle electromechanical dynamics model is verified.The results show that the optimized hollow axle of linear motor metro vehicle meets the design requirements.