Study On The Contamination Characteristics Of Line Insulators Under Fog-Haze Environment

Studying on the natural contamination characteristics of insulators can provide the operation and maintenance of electric power equipment insulation an important reference, in order to reduce the occurrence of flashover accidents. The insulation problem becomes more complicated and grim since fog-haze weather occurs frequently. This paper focuses on the contamination characteristics of line insulators under fog-haze environment.Firstly, this paper researches on the physical and chemical characteristics of line insulators under fog-haze environment. Based on a ± 800 k V DC transmission line, a 1000 k V DC transmission line, a 35 k V AC transmission line in Henan Provice, the contamination samples of the running XP-70 insulators under long-cycle fog-haze environment were tested. Water-soluble non-metallic ions, water-soluble metal ion, insoluble material, carbon-containing compounds, conductivity, PH value were measured and analyzed. Compared with the components of PM2.5 of the test points in Henan Province, in the aspects of water-soluble components, total carbon?TC?, particle aspects, it is found that PM2.5 is not the major source of insulator surface pollutants, while2 SO, NO₂ have great influences on the contents ofSO₄^2-, NO₃^- in insulator surface pollutants.Meanwhile, this paper analyzes on the contamination degree on the surface of XP-70 type insulator under fog-haze environment. The contamination test on the ± 800 k V DC transmission line shows that the lowest equivalent salt deposit density?ESDD? and non soluble deposit density?NSDD? are 0.038mg/cm² and 0.091mg/cm² respectively?in June?; while the highest are 0.113mg/cm² and 0.303mg/cm² respectively?in December?. ESDDs and NSDDs of insulators on varying height difference with the law of vertical distribution of PM2.5, PM10, 2NO concentrations. Based on the fiber ESDD measuring instrument, the measured ESDD daily increment in an experiment station in Pingdingshan region increases with AQI, approximately as Logistic fuction. Calculated by gray relation analysis method, it is found that among the fog-haze components, the pollution effect of SO₂ on soluble pollutants is greater, and the pollution effect of PM10 on insoluble pollutants is greater; with the increase of the concentrations of PM2.5, PM10, 2SO, 2NO in the air, the content of soluble pollutant rises more seriously.Based on fog-haze simulation device, the influence of major environmental factors of fog-haze on insulator contamination characteristics was studied. Experimental results show that with the increase of fog conductivity, ESDD approximately increases linearly, when the fog conductivity is low, wetting?even diluted? effect of relative humidity on the pollutants on insulator surface contamination is great; while fog conductivity is high, wet sedimentation effect of relative humidity is great, and ESDD increases as the corresponding humidity increases. Meanwhile, the influences of the components of fog, haze concentration, the type of solid particles on insulator contamination are little. Moreover, the hygroscopic solid particles can affect the relative humidity and indirect effects on insulator contamination. In simulated environment, the magnitude of ESDD increment contaminated for 9h is 10-3mg/cm², which means the impacts of environmental factors of fog-haze on insulator contamination are not significant.