Optimization Of Dynamics Parameters Of High-speed Pantograph-catenary System Based On Genetic Algorithm Theory

How to maintain a good and stable pantograph-catenary relationship is one of the key technologies of high-speed electrified railway.The dynamics parameters of pantograph and catenary system play a decisive role in the dynamic performance of pantograph-catenary system.When the high-speed train runs with double pantographs,the dynamic problem of the pantograph-catenary system is more complicated than that of single pantographs.When the high-speed train runs at high speed,the high-speed sliding of the leading pantograph along the contact line surface will cause the contact line to oscillate greatly,thus affecting the normal current receiving of the trailing pantograph.Therefore,it is necessary to study the dynamic current receiving characteristics between single and double pantographs and catenary system.The main work and conclusions of this paper are as follows:1)In this paper,the dynamic simulation platform of pantograph-catenary coupling system is set up with the elastic chain suspension catenary system and DSA380 high-speed pantograph as the research objects,and the simulation platform is calibrated according to the standard EN 50318:2018.The verification results show that the dynamic simulation platform of pantograph-catenary coupling system established in this paper meets the standard requirements and the calculation results are reliable.Using the control variable method,the influence of the change of equivalent stiffness k₃ and k₂ of the bow head,upper frame and equivalent damping c₁of the lower frame on the dynamic performance of pantograph-catenary system is studied in turn.According to the dynamic interaction evaluation standard of pantograph-catenary system,the single parameter optimization of pantograph is carried out,and the sensitivity evaluation grades of k₃,k₂ and c₁ and the best matching scheme of single parameter optimization of DSA380 high-speed pantograph are given.2)Based on the dynamic simulation platform of pantograph-catenary system and the global search strategy of genetic algorithm,the pantograph three-parameter joint optimization is executed,and the optimal solution of pantograph three-parameter joint optimization is given.The sensitivity analysis and ranking of the optimal solution are implemented,and the optimization effects of pantograph single-parameter optimization and three-parameter joint optimization are compared.The results show that the optimization effect of pantograph three-parameter joint optimization is better than that of pantograph single-parameter optimization.3)Considering that the current receiving quality of leading pantograph is better than that of trailing pantograph at high speed,the dynamic interaction between trailing pantograph and catenary system is optimized by genetic algorithm,and the optimal solution of joint optimization of three parameters of trailing pantograph is provided.Considering that the changed dynamic parameters of the pantograph may affect the current receiving quality of the leading pantograph.Three working conditions are designed for comparison and verification.The results show that the joint optimization of the three parameters of the trailing pantograph improves the current receiving quality between the trailing pantograph and the catenary system without affecting the dynamic performance between the leading pantograph and the catenary system.Finally,the influence of the change of average contact force of leading and trailing pantograph on the dynamic interaction of pantograph-catenary system is studied by using the control variable method,and the optimization scheme of average contact force of leading and trailing pantograph is offered,i.e.,smaller average contact force of leading pantograph and moderate average contact force of trailing pantograph should be selected.In this paper,genetic algorithm and control variable method are combined to optimize the dynamic characteristics between single and double pantograph and catenary system.The results show that the influence of joint changes of multiple parameters on pantograph-catenary coupling system should be considered comprehensively when optimizing the structural parameters of pantograph.The dynamic performance of pantograph-catenary coupling system at high speed can be effectively improved by increasing the equivalent damping of lower frame,the equivalent stiffness of bow head and reducing the equivalent stiffness of upper frame.The current receiving quality between the trailing pantograph and the catenary system can be improved by adopting a larger equivalent stiffness of the pantograph head,and the current receiving performance of the leading pantograph is not affected.The research results may provide reference and suggestions for structural parameter design of pantograph.