Providing outstanding in-service reliability in highly polluted environments for the Gulf States Power System Interconnection Project.
The problem of service reliability for the 400Kv transmission line was solved with the proven solution of applying rtv silicone HVIC.
The GCCIA (Gulf Cooperative Council Interconnection Authority) was challenged to provide a 400Kv transmission line together with connecting substations which operated in industrial and coastal areas but provided high reliability. This was a major project for a 400kV grid system interconnecting Saudi Arabia, Qatar and Kuwait over a distance in excess of 800 kilometres and which will eventually link up with the UAE Oman.
The major part of the transmission line route has close proximity to the Arabian Gulf and the presence of saline and other pollutants which rendered the insulators liable to frequent electrical flashover and subsequent power outages. The GCCIA wished to use ceramic or glass insulators as these have long proven high-strength characteristics, but when contaminated with pollutants they very quickly and frequently flashover.
The GCCIA considered various alternative methods of protecting the line insulators and substation bushings but wanted to achieve long term reliability and minimal maintenance cost. They eventually decided to use RTV silicone coatings which works by managing the insulator surface leakage currents and selected rtv silicone HVIC because of its long and outstanding history in successfully providing highly reliable service in industrial and coastal areas. RTV silicone HVIC has seen use in Saudi Arabia and other Gulf States since 1987 and with excellent long term maintenance free service.
The use of an rtv silicone HVIC which has been specifically designed to manage surface contamination is a long term, highly reliable and maintenance-free solution.
The GCCIA project was of massive proportions and planned to be installed over a period of about 18 months. The GCCIA/SNC-Lavalin awarded the contract to two electrical contractors NCC and Meedco each with a specific part of the 400Kv transmission line contract. The HVIC coating was subcontracted to S3C in Saudi Arabia who have been successfully applying rtv silicone HVIC supplied by Dow Corning’s master distributor, CCS Ltd., over a number of years. The sheer size of this project required that the insulators were in-factory coated by S3C in different locations using a specially designed production line; the insulator discs were strung in factory, boxed and shipped to site for installation on the line. S3C and CCS worked closely together to ensure a fast and well controlled coating process with in-process QA testing. The connecting 400Kv substations were coated on-site in the traditional manner by S3C.
RTV silicone HVIC has been in commercial use since the mid 1980`s and in the Middle East since 1987. A wide variety of overhead lines and substations have been coated very successfully but never on the scale of this GCCIA project which required the use of the in-factory coating close to the actual transmission line site.