Research On Multi-object Robust Control Strategy Of High-speed Pantograph

With the running speed of high-speed trains increasing,the coupling vibration of the pantograph-catenary system(PCS)becomes more severe and the pantograph-catenary contact force(PCCF)fluctuation becomes larger,which leads to the poor current collection quality of the PCS,and even cause arc discharge,contact line wear and other safety problem.It is an important problem to reduce the fluctuation of PCCF and improve the quality of the pantograph-catenary flow and ensure the safe operation of high-speed trains.In order to reduce the fluctuation of PCCF,this paper takes the finite element model of pantograph-catenary as research target,the multi-objective robust controller based on state estimation and the robust controller considering the actuator time delay are proposed,then verifies their effectiveness and robustness.Firstly,the multibody model and three level mass model of the pantograph are constructed,and the catenary model is established by using the finite element method.In the process of catenary modeling,the cantilever and support bar are equivalent to the concentrated mass point;the contact line and messenger wire are regarded as nonlinear cable elements;Similarly,the dropper is generally in the tensile state,so it can be regarded as a nonlinear bar element.A pendulum function is used to coupling pantograph and catenary to achieve dynamic simulation of PCS.European standard EN50318 was used to verify the validity of the PCS model.Secondly,considering the complicated working environment of the PCS,a Kalman filter is designed to obtain the state information of the pantograph.An indirect expression of PCCF is obtained by rewriting the dynamic equation,which reveals the positive correlation between the fluctuation of the PCCF and the drastic change in the acceleration of pantograph collector(PCA).By minimizing the PCA and reducing contact force fluctuations,a multi-objective robust control method based on state estimation is designed,and the effectiveness and robustness of the controller are verified by a nonlinear PCS model.The research results show that the designed controller can not only reduce the fluctuation of PCCF effectively,but also the demand for energy consumption is low.The proposed controller can also effectively handle the parameter perturbation of the pantograph and the irregularity of the contact line.Finally,in order to improve the reliability of the controller,a multi-objective robust control with random time delay is designed,in which each control objective can be given different weight coefficients according to its different functions,and achieve different control effects.The effectiveness and robustness of the proposed control strategy are verified by a nonlinear PCS model.The research results show that the controller can not only effectively reduce the fluctuation of PCCF,but also consume less energy,and can also effectively deal with the parameter perturbation of the pantograph and the irregularity of the contact line.