Research On Some Key Technologies Of AC25kV Overhead Conductor Rail

Overhead conductor rail(OCR)has many advantages,such as simple structure,high reliability,small tunnel occupation and so on,that make has been widely applied in urban rail transit.With the further expansion of the city scale,the flow of people in urban centers and suburban areas is more intensive,and Metro Express lines with higher operating speed and longer station spacing are urgently needed.The AC25 kV overhead conductor rail has a higher voltage level and has a longer supply arm than the DC power supply method,and the AC system has a smaller pantograph to take a smaller stream,and an AC pantograph with a smaller pantograph head mass is suitable for a higher speed urban rail train.Therefore,the AC Overhead conductor rail system is applicable to the design speed of 160km/h Metro Express Line.However,the research on AC overhead conductor rail in China is still in its infancy.Some of the design concepts of AC overhead conductor still follow the DC system with a speed of 100km/h or less.So it is necessary to carry out research on several key technologies of AC25 k V overhead conductor rail.In this dissertation,based on the finite element method,a coupled simulation model for AC rigid contact nets,pantographs,and pantographs was established.Through the simulation analysis of the existing 120km/h line,the online simulation results were used to verify the correctness of the simulation model.Then,a full-rate level pantograph dynamic interaction simulation was performed for different contact net spans.Through comparison analysis,it was found that a span of 6m is more suitable for a rigid contact network line with a speed of 160km/h.As for clamp,the influence of the elastic positioning clamp on the dynamic performance of the pantograph is analyzed by changing the positioning stiffness in the simulation model.It is concluded that the elastic clamp does not improve the dynamic performance of the pantograph of the AC overhead conductor rail.On the other hand,the dynamic performances of different types of anchor segment joints and AC pantograph are particularly analyzed in this paper.It is found through comparison and analysis that when the speed is 160km/h,all three types of anchor joints meet the standard requirements,but the pantograph-OCR contact quality is general.Specifically,the dynamic properties of fractured anchor segment joints are similar to that of the first type of inflatable joints,while the second type of inflatable joints are slightly inferior to both of them.By installing an elastic positioning clamp with an equivalent stiffness of 100 k N/m in the transition section,the pantograph-OCR contact quality of the fractured anchor section joint can be improved,but it doesn’t work for expansion joint.At the last,a new type of through expansion joint is designed,whose structure is simple,installation and adjustment are convenient.At the same time,the dynamic simulation of pantograph-OCR is carried out according to the joint length of different anchor sections.It is found that when the length of overlap is 2m,the new expansion joint and pantograph have the best dynamics performance at the speed of 160km/h.