Surface Flashover Characteristics in Vacuum of ZnO Varistor+Al2O3 Ceramic+ZnO Varistor Insulators

摘要

In this paper, ZnO Varistor+Al2O3 Ceramic+ZnO Varistor Insulators were made, in which the conductivity and permittivity of ZnO Varistors were controlled by changing its voltage gradient. Then the influences of conductivity and permittivity of ZnO Varistors on the DC and pulsed surface flashover voltage in vacuum were experimentally investigated. The experimental results indicated that the DC and pulsed surface flashover voltage of the three-layer insulators will be increased obviously while the conductivity and permittivity of ZnO Varistors have been controlled within a certain range.