Research On Active Control Strategy Of Pantograph Based On Predictive Control In High-speed Railways

With the rapid development of high-speed railways in China,the running speed of trains is continuously improved,and the coupling vibration between pantograph and catenary is more intense.The current collecting quality of the pantograph-catenary of high-speed trains becomes worse,which also leads to excessive arc and catenary wear and other problems,which affect safe and stable operation of high-speed railways.In order to reduce the fluctuation of pantograph-catenary contact force,based on the model of nonlinear pantograph-catenary system,robust predictive control algorithm based on state estimation and predictive control algorithm considering actuator time delay of high-speed pantograph are proposed.The effectiveness and robustness of the two proposed control algorithms are verified by simulations.Firstly,the mass model of pantograph,the multibody model and finite element model of the catenary are established.Among them,the parameters of the mass model of pantograph are obtained by frequency response method.The multibody model converts the pantograph components into bars with rotational inertia.In the finite element model,the messenger wire and the contact line are regarded as the cable element,dropper as the bar element,and support bar as mass point.The mass model of pantograph and finite element model of the catenary are coupled by pendulum function to obtain the pantograph-catenary system model.The European standard EN 50318 is adopted to validate the effectiveness of the pantograph-catenary model.Secondly,in order to solve the problems of measurement loss in sensors and measurement noise caused by strong electromagnetic interference in working environment of pantograph,a robust Kalman filter method considering measurement data loss is proposed.The state information of pantograph is obtained by this method,and the accurate pantograph state estimation parameters are provided for controller.Through the analysis of the control optimization equation,the contact force error is extended to the pantograph-catenary system state space equation.According to the expanded pantograph-catenary system state space equation,a robust predictive control method based on state estimation is designed.The effectiveness and robustness of the proposed control strategy are verified on the nonlinear pantograph-catenary system model.The results show that the proposed robust predictive control method can effectively reduce the fluctuation of the pantograph-catenary contact force and has little effect on the average value of the pantograph-catenary contact force when the pantograph model parameters are perturbed.Finally,in view of the actuator time delay problems in the control process,predictive control algorithm of high-speed pantograph considering actuator time delay is proposed.Based on the dynamic equation of the mass model,the correlation between the contact force of the pantograph-catenary and the acceleration of the pantograph collector is analyzed.A controller is designed to reduce the fluctuation of the acceleration of the pantograph collector and suppress the drastic change of control effect.The effectiveness and robustness of the proposed control strategy is verified on the nonlinear pantograph-catenary system model.The simulation results show that the proposed predictive control model can effectively reduce the fluctuation of acceleration of pantograph collector and pantograph-catenary contact force under the influence of model parameter perturbation and actuator time delay,and the average value of the pantograph-catenary contact force is almost unchanged.