Evaluation Of Interaction Between Overhead Contact Line Systems (OCS) And Pantographs For High Speed Lines

At present, China is constructing the high speed railway on a large scale. Due to the lack of practical experience in high speed range, there are many problems needing to be deeply analyzed and solved. The interaction between pantograph and contact line is one of them. Since the energy is transmitted to vehicles via catenary/pantograph system in electric high speed railways, fast, safe and efficient operation of vehicles to some extent depends on the performance of catenary/pantograph system. In the thesis, the evaluation of the interaction between pantograph and contact line is involved. Because there are no efficient criteria in China for estimating the performance of the catenary/pantograph system, the European standards was employed when doing the evaluation.Firstly, the thesis illuminates several essential problems about the interaction between contact lines and pantograph: coupling of two vibrating systems, sliding contact and the relation with environment. Then an overview of the research methods used in contact lines/pantograph interaction was carried out. The advantages and disadvantages of the different methods were analyzed. Based on the systematical summary of the existing standards about the evaluation of interaction between contact line and pantograph in the world, the simulation system was chosen for the study, in which three dimensional FEA model was used for the catenary system and mass-damper-spring model was adopted for the pantographs. Then the validation of the simulation system was carried out according to the standard EN50318, i.e. Validation of simulation of the dynamic interaction between pantograph and overhead contact line.Secondly, in order to investigate the dynamic performances of different pantograph/overhead contact line systems, the thesis chose two catenary systems without stitch wire based on the practical situation in China, and took two standard catenary systems with stitch wire at different speed grades as comparison. The dynamic simulation system was built in Ansys. After analyzing the elasticity and the dynamic characters of different systems, the thesis valuated the simulation results according to the series of European standards on the pantograph/overhead contact lines system. The evaluation of the dynamic performance was done taking current collection quality and safety into consideration. Based on the evaluation and comparison, the conclusion was drawn that the catenary systems with and without stitch wire are all suitable for the railways up to 250 km/h, and the catenary system with stitch wire can run at higher speed with satisfying performance. Above 300 km/h, the catenary with stitch wire is recommended.Thirdly, three catenary systems were employed for investigating the effects ofthe catenary parameters, such as the tensile force, the cross-sectional area, spanlength, system height, the stitch wire, the presag, dropper arrangement, contactwire gradient and the change in gradient, the irregularity, etc. Some optimalvalue ranges for the parameters were drawn from the study.Finally, some simulation and evaluation results were drawn from the study, andsome suggestions were proposed for the simulation, measurement and evaluationof the high speed catenary/pantograph system in China.