Power Frequency and Impulse Voltage Breakdown along Silicone Oil/Xlpe Interface

Power frequency (60 Hz) and Impulse Voltage breakdown characteristics of Silicone Oil (PDMS) with and without cross-linked polyethylene (XLPE) spacers have been studied. The electrode geometries were designed to simulate a high voltage cable termination. In the presence of a spacer, the breakdown stress under 60. Hz voltage remained nearly independent of gap length over the range of gaps studied. The results showed that the risk of discharge inception is low if the tangential stress, along the PDMS/ XLPE interface of a cable termination, does not exceed 1 kV/mm. Under impulse voltage the breakdown values for the liquid gaps with and without the spacers were approximately equal.