Development of new electrode system for measurement of high field dielectric properties near breakdown field

Abstract

In order to study the high field AC conduction mechanism near breakdown field, a new electrode system was developed using an evaporated polypropylene (PP) guard film. Using this technique high field dielectric properties of a biaxially oriented polypropylene (BOPP) film near breakdown field could be measured. The improved new electrode system enables the measurement of tan/spl delta/ in an electric field region 100kV/sub rms//mm higher than for the usual method, because there are no air voids between the sample film and the evaporated PP guard film. Furthermore we could measure the tan/spl delta/ and the dissipation current to about 270 kV/sub rms//mm, using a fast rising AC ramp voltage application technique.