Influence of dielectric polarization upon PD transients: Use of hollow dielectric spheres

Hollow glass spheres have recently been employed to provide a reproducible source of partial discharges. The influence of the shell permittivity upon the PD transients is examined. It is shown that, relative to the non-shell situation, the magnitude of such transients may be increased or decreased, depending on the ratio of the shell-to-bulk dielectric permittivities.