Research On Electric Field Analysis And Detection Of Insulators In Different States

With the rapid development of the power industry,a large number of insulators are used in the Transactionsmission and Transactionsformation lines of the power system.When there is a bad insulator in the insulator string of the Transactionsmission line,the insulation resistance is reduced,the insulation strength is decreased,it is easy to occur flashover,which poses a serious threat to the security of the power grid.Therefore,it is urgent to analyze the electric fields of the insulators in different states and to find out the proper detection methods of the deteriorated insulators.This thesis firstly analyzes the structure and degradation principle of the suspended porcelain insulator,analyzes the spatial potential distribution of the insulator string,and USES the finite element simulation software Infolytica ElecNet to establish the structure model of the suspended porcelain insulator string for simulation research.The spatial electric field distribution of 16 XP-160 insulator strings and 16 XWP-160 insulator strings is simulated.By changing the insulation resistance and relative dielectric constant of the insulator,the different states of the insulator are simulated,and the electric field distribution of the two types of insulator strings in different states is calculated,and then the electric field variation law of the insulator strings is further studied.The thesis shows that the degree of insulator deterioration(i.e.insulation resistance)and the number of pieces of the insulator have a great influence on the distribution of spatial electric field.The more the number of deteriorated insulator pieces,the greater the electric field distortion.Moreover,the electric field value of the insulators in different states varies linearly with the degree of deterioration(insulation resistance).Finally,the photoelectric electric field detection method based on pickles effect is analyzed,and based on the above research,combined with the electric field distribution measurement method,the feasibility of applying photoelectric electric field sensor to the detection of degraded insulators is studied,and the photoelectric electric field sensor is optimized according to the characteristics that the electric field change of low-value insulators is not obvious enough.