Improvement of external dielectric performance of vacuum interrupter

The present work intends to provide an improvement of external dielectric strength of Vacuum Interrupter (VI), in open air without additional polymeric encapsulation. The ceramic envelope of the vacuum interrupter has a big resistance to atmospheric conditions, and being less affected by aging. A particular VI design is suggested to achieve this goal, by increasing both, creepage and clearance, and reduce the effect of triple-points, increasing by that the dielectric performance of the VI. From the 3D FEM dielectric simulation we could compare qualitatively the potential of this design over the conventional one, which has been confirmed by the lightning impulse dielectric tests (BIL).