In conventional insulating materials,
an increased field strength can occur due to inhomogeneities in the
insulating material (air inclusions, conductive particles) or due to
the shape and surface quality of the confining conductive components
(roundings, edges or peaks). As a result the
partial-discharge-inception field strength can be reached and partial
discharges (PD) can arise. The related degradation of the solid
insulating materials will lead to a deterioration and finally to the
failure of the whole insulating part.

According to the present state of the art, the insulation is designed in a way that sources of such local field strength peaks are prevented under all circumstances. Such insulation systems represent a rather complicated and thus expensive solution. Therefore it is inevitably a goal of engineers to provide fault-resistant products.

A new solution approach for this
typical task of electrical engineering are innovative insulating
materials, which reduce field strength peaks by adapting their
properties under electrical stress. The aim of this study was the development of an insulating material with nonlinear field-grading properties for medium and high voltage applications.