Insulator flashover is one of the main failure modes of gas-insulated metal-enclosed switches. Increasing the flashover voltage of the insulator can effectively reduce the possibility of system failures. Previous studies have shown that insulator flashover under clean conditions mainly depends on the insulator surface electric field distribution

while the geometry of the insulator itself and its embedded and shielding electrodes can effectively adjust the electric field distribution along its surface. In this paper

epoxy post insulator samples were designed and casted. The distribution of

electric field along the surface was regulated by changing the shape of the insulator

the embedded electrodes and the outer shielding electrodes. The negative standard lightning impulse generator was used to study the flashover characteristics of insulator samples immersed in 0.2 MPa SF

6

. The finite element analysis method was used to determine the maximum value of the electric field along the insulator. According to the experimental and simulation results

the influence of insulator shape

embedded electrodes shape

and shielding electrodes shape on the insulator flashover characteristics is analyzed:the surface electric field of convex insulator has the best adjustability;the embedded electrodes can increase but can also reduce the flashover voltage of the insulator;the shielding electrodes can effectively uniform the electric field but may reduce the effective creepage distance along the insulator.