Study On The Contamination Characteristics Of V-type Double Suspension Rod Insulators Of OCS In Strong Wind Section Of Lanzhou-Xinjiang High-speed Railway

Lanzhou-Xinjiang high-speed railway is the first high-speed railway built in Gobi area of China,which passes through harsh ecological environment such as cold,plateau,dust and strong wind.Through on-the-spot investigation,it is found that sand with high salinity forms a dielectric layer with high conductivity on the surface of insulators,which easily leads to largearea flashover of insulators.Pollution flashover accidents have the characteristics of large scope,long time and wide spread.It has caused great economic losses to railway systems and is a serious threat.In order to prevent the extreme influence of severe weather such as strong wind on the line,V-shaped double suspension rod insulators are used on the line,and their unique structure increases the stability of the conductor.In order to ensure the safe,reliable and highspeed operation of trains on Lanzhou-Xinjiang high-speed railway,wind barriers are installed on both sides of the line.Due to the shielding of the wind wall,when the incoming wind blows to the insulator surface,the double-branch structure of the V-shaped double-suspension rod insulator is easy to form a wake in the flow field,which seriously affects the pressure distribution and contamination distribution on the insulator surface and affects the contamination characteristics of the insulator.In this thesis,the surface contamination characteristics of V-shaped double suspension rod insulators are studied.Firstly,it is verified by wind tunnel experiments that the shielding reason of the wind wall will increase the incoming wind speed and change its incoming angle under the condition of scale reduction,thus affecting the contamination characteristics of the insulator surface.Secondly,using Euler two-phase flow and fluid mechanics,a simulation model of insulator contamination was built.The surface contamination characteristics of insulators under different contamination conditions were simulated by setting different working conditions.Through the simulation diagram of insulator surface pressure and contamination distribution,it can be concluded that when wind speed,particle size,and particle concentration gradually increase,the pressure and contamination distribution on windward surfaces of two insulators gradually increases.The leeward surface of the 1#insulator produces a wake,which affects the pressure of the windward surface and leeward surface of the 1#insulator.The greater the pressure,the more pollution accumulates.There is a secondary wake on the leeward side of the 2#insulator.Because there is no obstruction behind it,the wake gradually disappears and becomes a common laminar flow.Finally,the insulator simulation of the insulators who use different flow angles to analyze the causes and rules of the insulator tail flow,verify the relationship between the insulator’s tail flow angle and the outflow field to flow,find out the direction of the tail flow of the insulator,explore the inquiry The law of the tail flow trajectory.The research results show that wind speed directly determines the static pressure on the surface of the insulator,the wind speed and particle concentration are proportional to the contamination volumes on the windward and cross wind sides of the insulator,while the particle size is inversely proportional to the contamination volume on the leeward side of the insulator.The direction of wake flow is consistent with the direction angle of external incoming flow,and the wake flow generation area affects the contamination characteristics of the insulator.When the incoming flow is at a prevailing wind direction of 0°,the focus should be put on the windward and crosswind sides of the two insulators during insulator cleaning,and the contamination distributions on these two insulators are close;when the incoming flow is at a prevailing wind elevation of 0°～60°,focus should be put on the entire surface of 1#insulator and the windward and crosswind sides of 2#insulator during insulator cleaning.The direction and angle of the external flow field of the insulator are consistent with the direction and angle of the wake generated by the insulator.The correctness of this conclusion is verified by the pollution accumulation test,and some suggestions are made for insulator cleaning.