Electrical assessment of commercial 6.0-kV HTV silicone rubber for power insulation

Silicone rubber has been widely used for electrical insulation in several power devices, e.g.: power insulators and metal-oxide surge arresters. In accordance with international standards, High-Temperature-Vulcanization Silicone Rubber for electrical power insulation should support 3.0 kV in electrical tracking and erosion tests, which are well established by the IEC. However, most of silicone rubbers used for manufacturing of electrical power components supports a maximum voltage of 2.75 kV. This research proposes a careful evaluation of the electrical performance of a new 6.0 kV silicone rubber developed by a worldwide-known manufacturer in the electrical power segment. The new silicone rubber is submitted to electrical tracking and erosion tests using two different approaches described in the IEC 60587: the step and steady methods. These two testing procedures are carried out in AC, following the normative recommendations, and also adapted for DC analyses. This research presents three principal contributions: a testing methodology considering both AC and DC, important conclusions on an emergent technology for electrical insulation in power systems and a quantitative analysis of erosion in polymeric composites based on the mass loss.