Research On Contact Force Control Method Of Pantograph Catenary System Of High-Speed Electric Multiple Unit

As an indispensable part of the train traction power supply system,the pantograph and catenary play a vital role in the process of obtaining electric energy for the train.The maturity of high-speed railway technology promotes the speed increase of the train,but it also produces some disadvantages.For example,the vibration between the pantograph and the catenary becomes more severe,which makes the contact force fluctuation range between the pantograph and the catenary become larger,not only making the poor current collection quality of the pantograph and the catenary,but also affecting the safe operation of the train.When the contact force of pantograph and catenary is low,it is plain to lead to contact-loss situation,which leads to generate arc and cause the train to lose power source;On the other hand,when the contact force between pantograph and catenary is too large,there occurs severe wear between pantograph and catenary,resulting in pantograph scraping,reducing the service life of the pantograph and increasing the cost of train maintenance virtually.Therefore,it is of great significance to study the contact vibration between the pantograph and catenary system of the train to ensure that the fluctuation of the contact force between the pantograph and catenary is reduced as much as possible.Based on the coupling model of nonlinear pantograph-catenary system,this paper aims to reduce the fluctuation range of pantograph-catenary contact force,and designs three different pantograph controllers in turn,taking into account the time delay and actuator saturation in the control system,the control effect are verified by simulation.Firstly,based on the coupling model of pantograph-catenary system,considering the flexibility of the pantograph head and the time-delay and actuator saturation in the networked control system,applying the Lyapunov stability theory and solving the corresponding linear matrix inequalities,a state feedback controller is presented to reduce the contact vibration between pantograph and catenary effectively.Finally,a simulation example of illustrates the efficacy of the proposed scheme.Moreover,as a consequence of technological limitations and high cost of sensors,it is also difficult to adopt active control methods in pantograph-catenary system,which leads to the inability to obtain all the system states commonly.Therefore,a H_∞active control strategy based on observer is proposed,using the Lyapunov stability theory and the linear matrix inequalities,the problem of non-convex feasibility of the designed controller and observer is solved by applying cone complementarity linearization procedure,the closed-loop system is asymptotically stable with a guarantee H_∞performance index.Finally,the effectiveness of the control method is verified by numerical examples.Considering that the exponential stability can make the controller more robust and the convergence rate can be controlled,an observer feedback control method based on exponential stability is proposed.The state delay of the pantograph is considered when the pantograph-catenary system model is established,applying a new exponential augmented Lyapunov-Krasovskii functional,by introducing an augmented weighted based integral inequality involving quadratic functions with an exponential term and extended reciprocally convex matrix inequality,the linear matrix inequalities with observer gain and controller gain matrices can be further obtained and a new sufficient condition for the exponential asymptotic stability of the pantograph-catenary system is developed.Finally,two numerical examples validate the superiority of the proposed stability criterion in reducing the pantograph catenary vibration.