Research On Vibration Detection For Catenary Based On Pseudo-random Sequences

Catenary is an important part of railway traction power supply system and is the precondition for ensuring the safe operation of electric locomotive.With the increasing speed of electric locomotive and the gradual increase of operation density,electric locomotive pantograph not only flow from catenary but also the influence that the impact and vibration caused by pantograph make greater impact for the overall structure of catenary are also becoming more and more worthy of concern.Under the background,in order to improve the reliability of traction power supply system,the paper studied the method of vibration detection for catenary.Firstly,considering the wide variety of catenary detection projects,a large number of literature studies on the detection of catenary are used to determine the vibration detection of catenary as the research direction.By analyzing the composition of catenary and the characteristics of contact suspension,the characteristics and measurement methods of the vibration signal on catenary are studied,at the same time,the principles of the pseudo-random sequence and various pseudo-random sequences are analyzed.Secondly,the dynamic analysis of pantograph and catenary is carried out to study the vibration model of pantograph and catenary,which can be coupled to the catenary and pantograph.The simulation analysis is performed by using the zero-pole distribution of pantograph-catenary transfer function which is used in the detection of catenary.The simulation is carried by the different situations on catenary and the result is shown that the detection effect is more effective than which is detected directly..Thirdly,in order to obtain the transfer function of the vibration of catenary,a pseudo-random sequence which is named m sequence and is similar to white noise has a good identification effect on the detection of catenary.Because of the least squares method has obvious shortcomings in data storage and online identification,the method of recursive identification of least squares method is applied to the catenary vibration detection of m sequence excitation,and the experimental data are identified by MATLAB software to verify the feasibility of the algorithm.Finally,the pseudo-random m sequence generator and the hardware and software circuit of catenary vibration detection system are designed.Vibration test experiments on catenary vibration test platform are conducted to simulate the fault of catenary.The experimental results show that the change of the zero pole distribution of the vibration transfer function of the catenary is close to the state of the catenary,and the feasibility of the detection method is verified.At the end of the paper,the research results are summarized,and the next research work is prospected.