Considerations on the impact of material mesostructure on charge injection at cable interfaces

In many industrialized high voltage applications, polymeric insulators are subjected to high electric field strength. Examples are cables, gas-insulated switchgears (GIS), capacitors and others [1]. The difficulty in the design process of these components is to ensure and predict their long-term reliability, where one among the important aspects is prevention of local degradation phenomena. Applications in which a combination of different solid dielectric materials are utilized, such as in cable joints or dry-type terminations are also becoming more common in the strive for achieving long lasting and maintenance free components. It is thus crucial that such components are also designed for longevity and faultless operation. This involves ensuring proper physical and chemical cleanliness of the used materials, but also optimizing component geometry with regards to local enhancements of electric field.