Research On Vibration And Protection Of Transmission Line Across HSR

When the high-speed EMU passes under the high-voltage overhead transmission line,the line will vibrate at a certain amplitude and frequency.Frequent chattering will cause fatigue damage to the transmission line.In severe cases,a wire drop accident will occur;it may also induce the transmission line to dance,the phase separation distance becomes smaller,and a flashover accident occurs.Therefore,it is of great significance to study the vibration characteristics of the high-speed rail overhead transmission lines and design the anti-drop backup clamps to ensure the normal operation of the railway and improve the power supply reliability of the transmission system.This paper focuses on the following research on the chattering and disconnection of high-voltage high-voltage transmission lines:Firstly,the disturbance of the high-speed rail to the electric field and flow field around the transmission line and the chattering effect of the disturbance on the line are studied.According to the electromagnetic principle such as Coulomb's law and the governing equation of fluid dynamics,the spatial electric field disturbance cloud image and the wind speed disturbance curve are obtained.The results show that the electric field disturbance is most obvious in the range of-5m~5m from the line;the flow velocity around the line fluctuates obviously,which is the main cause of the vibration characteristics of the line.Secondly,the wind pressure disturbance law of transmission lines considering high-speed rail parameters and ground height is studied.From the ground height of the transmission line,the length and speed of the high-speed rail,etc.,it is considered that for every 2m increase of the height of the line from the ground or 30 km of the speed of the high-speed rail,the instantaneous wind pressure drop at the measuring point is more than 10%,and the trans-high-speed railway line can be reconstructed accordingly..Thirdly,the tremor response generated by high-speed rails caused by high-voltage transmission lines is studied,and the finite element model is verified by combining the vibration measurement data.Under the action of the EMU airflow,the main vibrations of the single and double split lines occur in the horizontal and vertical directions,while the vibration along the line direction is negligible,and there is no resonance phenomenon when the line vibrates;The vibration measurement scheme is designed for field test.The displacement extreme value of the finite element calculation agrees with the test data,which indicates the rationality and scientificity of the line vibration characteristics.Fourth,the scheme of anti-vibration off-line is studied and the backup clip is designed.Summarize the existing line anti-drop line work(equipment),carry out the backup line clip design and carry out safety verification.The backup protection line clip has sufficient feasibility and is safe and reliable,which can effectively prevent the occurrence of chattering and disconnection.Through the research and analysis in this paper,it can provide reference and basis for studying the vibration phenomenon of other "three-span" high-voltage transmission lines,and further improve the working efficiency and power supply reliability of the transmission system.