Study On Dynamic Contamination Deposit On The Suspension Insulators Of Power Transmission Line

Outdoor transmission line and substation electrical equipment often suffer from industrial contamination or natural salt, dust, bird droppings and other contamination. When the humidity is high, such as fog, dew, drizzle, snow melt and other adverse weather conditions, the insulation surface contamination will be wet, under the applied voltage, the surface conductivity and leakage current will significantly increase, which may lead to the pollution flashover. For the practical guidance to maintain the grid, currently being used, there is a certain lag that is not accurately reflecting the current status of the actual pollution of external insulation. On how to timely and accurately predict the status of pollution of external insulation to predict pollution flashover risk of the actual operation, to guide the leakage distance modulation and the external insulation design, there is little reported.In light of the characteristics of the study, this paper started from the analysis of the process of the particles deposited on the insulator surface, highlighted the analysis of particles deposited on the insulator surface to study the physical process of insulator contamination. Use this method to predict the situation of the contamination on the insulator, to make the accurate prediction of the insulator running status possible. On the theory of dynamic contamination on the insulators, this paper has made some preliminary results, analysis of the atmospheric particles of natural sedimentation process and the process that in the relatively dry conditions particles removed form insulator surfaces in the wind are made. The conditions of the particle adhered removed by wind are deduced, the lesser the particle size is, the more easily being removed, the larger the wind speed is, the more easily particles being removed. And theoretical analysis was tested.The pollution experiment of non-charged string further illustrated the nature contamination model is reasonable. The paper also pointed out that in the natural environment for the suspension line suspension insulators, generally the total suspended particulate of the air higher, the more serious insulator surface pollution. For the insulator upper surface, in the areas that wind speed is large, the contamination will have a greater reduction in severity. For the lower surface, wind speed generally little effect on the severity of the contamination, but the composition of pollutants in the environment impact the insulator salt density greater. Generally for insulator, in the absence of rain, the upper and lower surface of salt density growth larger with time, the salt density of the upper surface growth with better statistical law.This paper advantaged the dynamic contamination theory of suspension insulators. Based on the dynamic contamination theory, the methods to guide the pollution flashover prevention are put forward. The pollution flashover warning software is made.