The Research On The Wire Surface Roughness Changes Under The Sand Environment And Its Effects Of Corona Characteristics

Its necessary to explore its causes that750kV uhv transmission line coronaloss of northwest power grid. Each year the line suffered from severe sandstormclimate as it mainly works through the northwest desert area， so its necessary toresearch sandstorm impact effecf on the transmission conductor corona losssituation in addition to high altitude, filthy. This selected topic have importantguiding significance to explore more transmission line corona loss of sand dunesenvironment impact factors and properties, and have important reference value tostudy the sand environment reduce corona loss measures.Based on studying a lot of relevant material about sand dunamics theory andtheory of erosion wear, the flow field around the flow theory, corona measurementtheory during thesis progress. To meet the needs of the physical simulation ofnorthwest sandstorm climate environment, reasonable transformation was done inthe existing wind tunnel laboratory. The corresponding wind speed regulating andmeasuring device and dust concentration measuring instrument were configured inclosed wind tunnel experiment system. Wind sand flow around conductor areanalyzed in numerical simulation by FLUENT, the vorticity, wind speed anddynamic pressure and other parameters were concluded to work out the testobservation point of the wire. Through comparison and test of a variety of surfaceroughness measuring method, this paper selects the light microscope method fornon-contact surface roughness measurement, as the transmission wire is steel corealuminum stranded wire, its outer materials was soft aluminum stranding. Specialtreatment was needed when measuring because each root aluminium conductorspiraling, its surface roughness measurement is not the general rules of the cylinder.This paper presents two correction methods, dyeing method and ratio correction method. By comparing the actual effect, the ratio correction method is moresuitable for measurement in this paper.According to the existing conditions, two phase of the testing scheme isworked out, and after each subsection test cut using light microscope and externalequipment to measure the surface roughness of the wire, and using home-madeequipment such as high voltage corona cage to measure corona characteristics. Onthe roughness values and get dizzy voltage data, summarize after post-processinganalysis, draw a conductor surface roughness variation law and its relationship withcorona characteristics.