Research On The Behaviors Of Friction And Wear With Electric Current And The Optimal Load Of Pantograph-Catenary System

In the current-carrying system of electric locomotive, pantograph slider plate and contactwire constitute a pair of mechanical and electrical friction components under the specialconditions. The state of its frictional wear decides whether current-carrying system of electriclocomotive can work normally and reliably. Along with continuous speed acceleration of electriclocomotive, it appears more stability problems of current-carrying. Therefore, it has realisticsignificance to predict and evaluate of the friction and wear property of the electric locomotivepantograph slider plate and contact wire.Firstly, a sliding electrical contact friction and wear tester was improved based on thebehavior of high-speed and current–carrying friction wear, which can simulate electriclocomotive’s real operation condition. Through conducting lots of experiments on immersedcopper carbon pantograph with copper-tin contact wire and copper-silver wire, friction and wearbehaviors are studied under high current, heavy loads and high sliding speed. Thecurrent-carrying friction and wear characteristics are obtained by studing those dates. The wearmorphologies of pantograph are analyzed by using SSX-550scanning electronmicroscope. Theresults show that the relation between friction coefficient and load, contact current and slidingspeed is non-linear, and the coupled relation among pantograph wear rate, load, contact currentand sliding speed is more complex. Using the theory of wear steady-state, a optimal load exists,which can make the wear minimum with fixed contact current and sliding speed. By studing theprocess of research and the current quality, it shows that the running-in period gets longer withthe bigger of current, the average wear rate is bigger also at different currents and loads. Theload is more important to the current quality and wear rate of slide.Secondly, this paper uses the non-linear regression theory to predict the friction coefficientand pantograph wear rate. The results show that the function relation of friction coefficient withcurrent, sliding speed and load accords with a power function relation. The prediction accuracyis less than7%. The relationship between wear rate, load, contact current and sliding speed ismore complex, it is both polynomial and power function, the prediction accuracy is less than8%.Nextly, taking advantage of improved RBF Neural Network Algorithm to predictpantograph wear rate, the results show a good effect as prediction, and the prediction accuracy is higher than on-linear regression algorithm.Finaly, considering four influencing factors, in view of different contact currents and slidingspeeds, and use Fuzzy Comprehensive Evaluation to study influence that loads to frictional wearproperty and current-carrying property, through establishing effective appraisal system, anevaluation standard of optimal load can be achieved.