Electric field analysis of transmission line insulator strings under different deterioration conditions

With the rapid development of the power industry, a large number of insulators have been used in the power transmission lines of the power system, and the existence of deteriorated insulators is a direct threat to the safe and stable operation of the power system. When the transmission line insulator string has deteriorated insulators, the insulation resistance and insulation strength will decrease, and flashover will easily occur, posing a serious threat to the security of the power grid. Therefore, it is necessary to analyze the electric field of insulators in different states and develop appropriate detection methods for deteriorated insulators. In this paper, firstly, the structure and deterioration principle of suspension porcelain insulator, as well as the spatial potential distribution of insulator string are analyzed, and the structural model of suspension porcelain insulator string is established by using the finite element simulation software ANSYS for simulation research. The spatial electric field distribution of 16 XWP-160 insulator strings is simulated. By changing the insulation resistance and relative permittivity of insulator piece to simulate the different states of insulator piece, the electric field distribution of insulator string in different states is calculated, and the electric field variation law of insulator string is further studied. The research shows that the degree of insulator deterioration (insulation resistance) and the number of deteriorated insulators have a great impact on the distribution of space electric field. The deeper the degree of deterioration, the greater the electric field distortion; The more the number of deteriorated insulators, the greater the electric field distortion. The change of electric field value of insulator under different conditions varies linearly with the degree of deterioration (insulation resistance).