Prediction Of Contamination Depositing Characteristics Of Insulators Based On The Similarity Principle

The insulator plays a role of mechanical support and electrical insulation in the power system,and its insulation performance directly affects the safe operation of the power system.Scholars at home and abroad have carried out a lot of qualitative research on the contamination depositing characteristics of the insulator,and found that the effects of wind speed,particle size and other factors on the natural contamination depositing characteristics of the insulator are consistent to a certain extent.However,few people have considered the quantitative relationship between various factors affecting the contamination depositing of the insulator and their pollution accumulation.Therefore,it is necessary to use the similarity principle as the basis to explore the quantitative relationship between the various influencing factors of the insulator contamination depositing and its pollution accumulation in order to predict the insulator pollution accumulation and achieve timely cleaning,so as to ensure the safe operation of the power system.Taking the typical insulator as the research object,the wind tunnel contamination depositing characteristics of XWP₂-160 porcelain double umbrella insulator and FXBW-330/120 composite insulator are simulated by COMSOL software.The numerical simulation results of two insulators are compared with experimental results,which verified the rationality of the numerical simulation method.Therefore,on the one hand,using COMSOL software to simulate the contamination depositing characteristics of XWP₂-160 porcelain double umbrella insulator and FXBW-110/100 composite insulator under natural conditions,the influence of wind speed and particle size on its natural contamination depositing characteristics is discusses,and it is found that there is consistency with the literature research results.On the other hand,the influencing factors and dimensions of contamination depositing characteristics of two kinds of insulators are analyzed,and two new criteria Ly and Lw are proposed based on similarity principle.The established and undetermined criteria of two kinds of insulators are deduced and the correlation between them is explored.By using 1st Opt data fitting software,the quantitative relationship between similar criteria of two kinds of insulators is fitted,and the corresponding criterion correlation formula is obtained.The main qualitative research results show that:1)The numerical simulation method of the insulator’s contamination depositing characteristics is reasonable.2)There is a positive linear correlation between wind speed,particle size and pollution accumulation of the porcelain double umbrella insulator,which is consistent to the simulation results in the literature.3)With the increase of wind speed and particle size,the composite insulator pollution accumulation increases approximately linearly,which has good consistency with the results of literature simulation.The quantitative results show that:1)The fitting accuracy of linear fitting and power function fitting on dimensionless correlation formula of the porcelain double umbrella insulator is 0.968 and 0.946 respectively.2)The fitting accuracy of linear fitting and power function fitting on dimensionless correlation formula of the composite insulators is 0.824 and 0.601 respectively.3)In the two fitting forms,the corresponding values of the porcelain double umbrella insulator are better than the composite insulator,which may be because the contamination depositing of the composite insulator is more prone to saturation than that of the porcelain double umbrella insulator.4)The dimensionless criterion correlation formula can predict the amount of pollution accumulated by the insulator in engineering practice,reducing the rate of pollution flashover accidents and ensuring the safe operation of the power system.