Impact of Contact Pressure on Breakdown Strength of Solid-Solid Interfaces

Emre Kantar, Dimitrios Panagiotopoulos, Erling Ildstad
2017 Proceedings of the Nordic Insulation Symposium  
<p>Solid-solid interfaces are considered as weak points of<br />the insulation since combination of two solid dielectrics<br />increases the risk of cavities and moisture at the interface<br />against the tangential component of the applied electrical<br />stress. The main objective of this paper is to investigate<br />the impact of the applied contact pressure on shrinkage<br />of the size of cavities on the interface that leads to<br />enhancement in the breakdown strength. Experimental<br
more » ... Experimental<br />measurements of AC 50 Hz breakdown voltage of solidsolid<br />interfaces assembled under standard laboratory<br />conditions were conducted using two different<br />specimens, namely XLPE and silicon rubber. For the<br />same applied contact pressure, breakdown strength of<br />XLPE-XLPE and silicon rubber-silicon rubber interfaces<br />were also analyzed to yield the influence of elasticity<br />modulus (softness) of the solid material on the<br />effectiveness of the applied pressure. Two different<br />levels of contact pressures were applied for each type of<br />interface and higher interfacial pressure (8.02→11.59<br />bar) led to improved breakdown strength about 50% for<br />XLPE-XLPE interface whereas the enhancement for the<br />much softer interface (i.e. silicon rubber) was about 7%<br />under increasing pressure (1.34→2.67 bar).<br />Additionally, breakdown strength of silicon rubber<br />interface was found to be higher than that of XLPE<br />interface around 53% at the same applied pressure.</p>
doi:10.5324/nordis.v0i24.2280 fatcat:5bbpasuquzfull6yxobfvaijua