Applicability Study Of Pantograph-catenary Modeling Method In Urban Transit System

With the fast development of economy in our country, the conventional public transportation have been unable to meet the demand of urban passenger transport. Under the national policy support and guidance, many cities have started to build subways, trams and other urban transit projects. Urban transit system use electric traction and the good current collection needs continuous contact between pantograph and catenary. So the research of pantograph-catenary dynamic is one of the key technologies of electric railway. In this paper the pantograph-catenary system of urban trasit has been investigated as follows.Firstly, focused on the three kinds of catenary which are widely used in urban transit system, namely the rigid catenary, simple elastic suspension catenary and simple chain suspension catenary, this paper sets up their mathematic model and discusses the regulation of modal characteristics. Based on the rigid catenary equivent model, a variable-stiffness spring model is given.Secondly, an easier calculating method is come up with to get the equivent parameter of lower frame. Then by the test and calculation, the equivent models of CED125D pantograph under different working height are acquired. Compared with the results of Frequency response test, the equivent models turns out to be correct.Thirdly, based on the rigid catenary, the appropriate selection of the modal truncation number and the finite element size, that is separately used in modal superposition method and direct modeling mehtod, which affect the calculation accuracy and efficiency is discussed. The models of catenary and pantograph have their applicability. For the rigid catenary, variable-stiffness spring model is applied in the dynamic calculation to determine its applicability. Focused on the two mass equivent model and three mass equivent model, their applicability under different kinds of catenary is studied.Finally, because the rigid catenary and flex catenary are both used in urban transit system, there exists overlapping span and transition structures. Based on the applicability study, an appropriate model is selected to study the dynamic behavior under these line conditions. At the same time, because of the elastic inhomogeneity, the contact force between pantograph and catenary fluctuates cyclically. An active control strategy is put forward to restrain the fluctuation and improve the current collection.