Study On The State Analysis And On-line Monitoring Of The Catenary In The Gale Area

The territory of our country is vast and the climate of our country is complex and diverse.There are many wind gaps along some of the railways of China,and the railway equipment failures often occur under strong wind power.The catenary is an important part of the electrified railway.As a non standby system,the catenary breakdown will directly cause the train to stop,and economic losses will be caused.The on-line monitoring of the catenary can find out the breakdown and the hidden danger in time,and it can effectively improve the reliability of power supply.However,the catenary is very sensitive to wind load,the wind will change the state of the catenary and then cause some interference to the fault diagnosis results of the on-line monitoring.At present,there is not a set of on-line monitoring device for catenary which is used in wind area.Therefore,on the basis of the analysis of the regular pattern how the wind effect the catenary,a set of on-line monitoring device for the catenary in the gale area is developed.It is of great significance to improve the safety and reliability of the railway operation in the wind area.In this paper,we first establish the finite element model of catenary which regards the Lan-Xin high speed railway in gale area as the object.The Davenport spectrum is used as the target spectrum,and the weighted amplitude wave superposition(WAWS)method is adopted to simulate the fluctuating wind field.Then we carry out the streaming simulate experiment of contact wire in wind-sand two phase flow field by the computational fluid dynamics software Fluent.We can obtain the change regulation of aerodynamic parameters of contact wire under different conditions as well as the wear regulation under the action of wind and sand load.Then we can calculate the pulsating wind sand load according to the aerodynamic theory formula.The generated wind sand load is applied to the catenary model and the nonlinear transient dynamic simulation of catenary is carried out in finite element software ANSYS.We can obtain the law how the wind sand flow effect the vibration of catenary and the variation of the vibration amplitude of the catenary with the change of the parameters such as span and tension.The dynamic response behavior of b value when catenary broken line occurs is simulated,and the mechanism of the change of b value caused by wind loads is inferred.Through the finite element simulation experiment we can find that when the wind speed reached 43m/s the maximum vibration amplitude of half anchor section catenary made up by 12 spans is 63.15mm,which has reached the drop distance 63mm of the pendant when the compensator has broken line.So it is very easy to confuse the both if the monitoring device identifies the broken line fault by the change of the b value when the wind speed reaches a certain value and it is necessary to take measures to exclude the disturbing factors.According to the characteristics of the broken line signal and the wind vibration displacement signal of the catenary,we choose the modulus maxima method based on wavelet transform and distinguish the two signals by calculate the Lipschitz exponent of singularities of the signals.Through calculation we can find that when the wind vibration displacement is less than or equal to the broken line displacement,the maximum value of the Lipschitz exponent detected at the broken line point is not more than 0.15 and the minimum value of the Lipschitz exponent detected in the wind vibraiton period is not less than 0.34.It shows that the method of setting the Lipschitz exponent threshold is feasible,and the general monitoring algorithm of broken line signal is designed according to this mean.The algorithm can be used when the wind speed is 0?50m/s(0?15 level).On the basis of the research of the wind induced vibration of the catenary and the monitoring arithmetic we finally design the on-line monitoring device for the catenary in the gale area.The device adopts the DSP chip TMS320F28335 as the processor and it is composed of signal collection and processing module,DSP data collection and processing module,display and communication module.The monitoring contents include the b value of contact wire and carrier cable,the field wind speed and the environment temperature,and the device can effectively identify the breakdown such as the broken line of contact wire as well as overrun or clamping stagnation of the compensator.The device is now installed in the Jiayuguan power supply section of the Lanzhou Railway Administration,and it works well on the spot.