Research On Statistical Method Of Breakdown Of Polyethylene And Its Nanocomposites

Nowadays,a great deal of research has been done on the breakdown of modified polymer materials,and significant achievements have been made.However,there are few studies on the statistical methods of breakdown of modified polymer materials.Most of the studies are based on the Weibull distribution to deal with the data,and finally the characteristic breakdown is calculated.But the relationship between breakdown of the modified polymer materials and the statistical distribution of Weibull,the optimal statistical distribution method to count the strength of the breakdown of nanocomposite insulation material,and the research on this aspect are almost uncertain.In view of this subject,the following work arrangements are made:Firstly,the research results of the breakdown characteristics of polyethylene and its nanocomposites in recent years are summarized,and the breakdown behavior of polymers is studied in detail,including the theory of electrical breakdown theory,thermal breakdown theroy,electrochemistry breakdown theory and the statistical analysis of the dielectric breakdown data.Combined breakdown theory is used to explain the breakdown behavior of polymers.Secondly,the direct current breakdown test and AC breakdown test of pure low density polyethylene（LDPE）,MgO/LDPE polymer and SiO₂/LDPE polymer are carried out.The normal distribution statistical function,the Weibull distribution statistical function,the Logistic distribution statistical function and the maximum distribution statistical function are used for the LDPE,MgO/LDPE polymer and SiO2/LDPE polymers.The DC breakdown field strength data and the AC breakdown field strength data are analyzed statistically.The statistical results are checked and the statistical results are evaluated with two numerical values of P value and Anderson-Darling statistics in the hypothesis test,and the optimal statistical analysis method is selected.Finally,through the analysis of the statistical results,it is found that the normal distribution function is suitable for many factors affecting the same characteristics,the factors are relatively independent and their influence size is the same.It is suitable for the breakdown data for the statistics of nanocomposite materials and the direct current strike data of pure polyethylene.The Weibull distribution function belongs to the weak click wear.It is the weakest link in the single stable unit.It is suitable for the data analysis of the AC breakdown field strength of pure polyethylene.