Reliability and cost effectiveness of silicone rubber insulators in the eastern coastal industrial area of Saudi Arabia

The Saudi Electricity Company (SEC) is the only electricity company in the Kingdom of Saudi Arabia. More than 37% of the load of Eastern Region Branch (SEC-ERB), which was formerly known as (SCECO-East), is industrial and mainly related to oil and gas extraction and is critically sensitive to voltage fluctuations (dips). Its electric network operates under very harsh environments. These environmental conditions make insulator contamination flashovers the main concern to the electric utility. Different solutions were tried to combat the insulator pollution flashover. These measures significantly reduced the number of insulator flashovers, but increased their acquisition and maintenance costs. Therefore, it was necessary to identify an insulator of low life cycle cost (LCC). Silicone rubber (SiR) insulators are generally acknowledged by their superior pollution performance. However, true performance can only be evaluated by putting the insulators in service. Accordingly, a line exposed to coastal industrial environments was selected for evaluation. This study comprised of laboratory and field investigations. Laboratory investigations focused on the chemical, physical and electrical properties. Manufacturers and independent laboratories were used to perform those tests. As field performance is the definitive guide for validation of laboratory tests, field investigations commenced simultaneously. The test insulators were periodically checked by visual inspections carried out during daytime and at night, to check for possible audible corona, partial discharges or unusual conditions. Test results showed negligible changes in SiR insulator properties and no electrical or mechanical failures were experienced. LCC and reliability indices (RI) demonstrated their excellent performance in the test area. The performance of SiR insulators in this area is satisfactory.