A study of factors affecting the breakdown strength of silicone rubber

The breakdown strength of silicone rubber (SIR) and its variation with gap spacing for small Rogowski profile electrodes is investigated. The electrical behavior of built-in interfaces inside the SIR (the interfaces being parallel or perpendicular to the applied electric field) is also studied. The breakdown strength of SIR is found to decrease with increasing gap spacing. The role of interfaces is emphasized, in particular those parallel to the applied electric field. The present results indicate that such interfaces are not necessarily the site of a breakdown. The processing technology, in creating such interfaces, plays a dominant role in whether they become sites of breakdown