Ionic conduction and field grading in dielectrics

Abstract

In many practical insulation systems, failure initiates at asperities or inclusions at which very high localized fields exist. It is the purpose of this work to examine a method for modifying the insulation so that field grading will occur and the buildup of excessive fields be prevented. In order to accomplish this field grading, we propose to take advantage of the field-dependence of the conductivity of weak electrolytes, the so-called second Wien effect.1 The phenomenon is well understood and documented2 and involves the increased dissociation of weak electrolytes into ions with increased electrical fields, producing a higher conductivity in the high field region and therefore a reduction in this field.