Research On Active Control Strategy Of Pantograph Based On Linear Quadratic Form

During the operation of high-speed trains,the speed will directly affect the flow quality of the pantograph-catenary system,and the increase of speed will lead to the deterioration of the flow quality of the pantograph-catenary system.In order to improve the flow quality of the pantograph-catenary system,this paper adopts linear quadratic optimal control to actively control the pantograph-catenary coupling system,and optimizes the linear quadratic optimal control algorithm by genetic algorithm,and achieves good control effect.The research contents of this paper include:Firstly,DSA350 S,DSA380 and SS4 pantographs are selected as the research objects,and a pantograph network coupling dynamics model is built to meet their characteristics.The running speed of the train is set to 250km/h,and the contact force and the longitudinal displacement of the bowhead of the three types of pantograph systems are analyzed for passive control,and the data are used as a control group to evaluate the optimization effect of the active control strategy.Secondly,the active control of the pantograph-catenary coupling system is carried out by using type I fuzzy PID control and interval type II fuzzy PID control respectively,and the active control force is applied to the transmission mechanism through Simulink simulation,and the active control force is applied to the pantograph frame or bow head through the transmission mechanism,so as to obtain the active control force of DSA350 S,DSA380 and SS4 at 250km/h running speed.The optimized results of the contact forces and longitudinal displacements of the head of DSA350 S,DSA380 and SS4 pantograph coupling systems under the above active control strategy are obtained.Finally,the LQR optimal control strategy is proposed to improve the dynamic characteristics of the pantograph-catenary system by adding time variables to the system matrix A(t)to extend it to three-dimensional space,and then introducing the changes of the system matrix into the feedback gain matrix through the Riccati equation,and finally controlling the active control force through the time-varying feedback gain matrix to dynamically improve the dynamic performance of the pantograph-catenary system.To address the difficulty of designing the optimal control power matrix of LQR,the global search capability of genetic algorithm is used to find the optimal power matrix.Firstly,the objective function is designed according to the control objective of the pantograph-catenary system,and all possible solutions of the problem are assigned to the power matrix in turn,and then the optimal solution of the power matrix is obtained by finding the optimal solution of the power matrix under the constraints of the objective function,and finally the optimal solution of the power matrix is applied to the LQR optimal control to obtain the time-varying feedback gain matrix,and the feedback gain matrix is used to improve the dynamic performance of the pantograph-catenary system,and good control effects are achieved.