Article of the week
Reviewing Modes of Insulator Failure
There are three proven insulator technologies being deployed in delivery of electrical power throughout the world. Porcelain and glass insulators have been used since the start and have had a solid record of performance and reliability. In fact, the success and rapid expansion of overhead networks could never have been possible were it not for ...
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Pollution & Ageing Performance of Composite DC Line Insulators: Service & Test Experience
About 20 million composite line insulators are already in service on HVAC overhead lines all over the world. Moreover, the growth in market penetration of this technology seems exponential. The first installations were in Germany in 1967, predominantly in... Read More
Safety Testing of HV Cable Terminations, Bushings & Arresters
Several years ago, a HV cable termination operating in a Mediterranean country experienced catastrophic failure, scattering high velocity porcelain shards in all directions. The installation was next to a parking lot but fortunately the failure occurred when... Read More
Insulator Corrosion Affected HVDC Lines in China
In March 2011, problems of electrolytic corrosion on the caps of ceramic cap & pin insulator strings began appearing on the world’s first ±800 kV HVDC line, located in southern China. This line – known as Chu-Sui – runs across 1200 km of mostly... Read More
Modular HVDC System Interconnects Countries of Arabian Gulf
American inventor and ardent DC advocate, Thomas Edison, seems destined to have the last laugh. Progress in power electronics and insulation design over recent years have finally helped DC achieve major gains against AC systems which, despite Edison’s... Read More
Transmission Line Arresters Lower Losses & Increase Reliability
Given the possible application of line arresters to mitigate the effects of lightning, it strikes me as inexplicable that arresters are not being used more often to reduce momentary lightninginduced outages on transmission lines. I have asked experts to... Read More
Reducing Ice Accretion Using ‘Super-Hydrophobic’ Coatings on Conductors & Insulators
CIGRE Brochure 438 (2010) reviews systems to predict and monitor ice accretion on power networks and also discusses the different anti-icing and deicing methods currently available. These countermeasures are divided into both ‘active’ methods (such as... Read More
Norwegian Utility Re-Dimensioned Insulation in Voltage Upgrade Project
Norwegian power utility, Statnett, operates a network of over 10,000 km of overhead lines from 132 to 420 kV. Recent changes in power flow made it necessary to increase capacity so, like many transmission system operators, Statnett is working towards building... Read More
