Simulation of transient response characteristics in coaxial electrodes with non-linear insulating dielectrics

Under the step voltage, the non-linear conductivity dielectrics have the function of grading the electric field. But such materials have been applied extensively under AC electric field, and insulating materials damaged mostly under impulse voltage. The research on the AC response characteristic presents the foundations for the development and application of non-linear insulation dielectrics. In this paper, the coaxial electrodes structure filled with non-linear conductivity dielectrics is taken as main research object, and the finite element method (FEM) software ElecNet is adopted to simulate transient electric field distribution in the non-linear conductivity dielectrics under AC voltage. The result indicates that under AC, according to the theory of space charge limited field, the capability of the non-linear dielectrics in grading field is determined by the dominator of resistive current and capacitive current. When resistive current is larger than capacitive current, the non-linear conductivity dielectrics have the function of grading the electric field, vice versa.