Helping Understand the VI Characteristic Curve

January 13, 2018 • ARTICLE ARCHIVE, Editorial Columns, Woodworth on Arresters Comments (0)

The voltage-current (VI) characteristic of its varistor is without doubt one of the most important parameters of any surge arrester. Still, most arrester users do not see this characteristic represented in graphical form but rather only as tables of discharge and reference voltages. Looking more deeply ‘behind’ such tables and to the data that actually ...

Read More



Birds: More Threat to Lines or Threatened by Lines?

January 6, 2018 • ARTICLE ARCHIVE, Utility Practice & Experience, Wildlife Protection Comments (0)

As industrial contamination is coming under more and more scrutiny and control in many countries, the issue of flashover outages attributed to birds (often included under the category of ‘unexplained outages’) is becoming a growing problem. As service...

Transmission Line Arresters Lower Losses & Increase Reliability

January 2, 2018 • Article of the week, Utility Practice & Experience, Woodworth on Arresters Comments (0)

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...

Insulation Aspects When Converting Transmission Lines from AC to DC

January 13, 2018 • ARTICLE ARCHIVE, Utility Practice & Experience Comments (0)

The ongoing expansion of wind power is placing growing demands on the dynamic capacity of transmission systems and utilities are therefore looking closely at how their existing lines can be utilized more efficiently. In this regard, one attractive way of...

RIS Bushing Technology: Reliability Testing & Field Experience

January 27, 2018 • ARTICLE ARCHIVE, Bushings, Testing Comments (0)

Problems with bushings are one of the leading causes of transformer failure and that means their proper selection can significantly impact transformer and substation safety. Traditional bushing technologies such as oil-impregnated paper bushings (OIP) and...

Coating Glass insulators for service in severe environments

Coating Glass Insulators for Service in Severe Environments

January 2, 2018 • ARTICLE ARCHIVE, Glass, Insulators Comments (0)

RTV silicone material has been used to prevent pollution flashovers at substations for more than 30 years. More recently, this same remedial measure has also been adopted by power utilities worldwide to resolve service problems due to extreme contamination...

Ice Storm in North America

January 6, 2018 • ARTICLE ARCHIVE, Utility Practice & Experience Comments (0)

This week, 20 years ago, was marked by one of the most massive power outages in North American history. Much on the North-East was affected but especially the Canadian Province of Québec, where hundreds of transmission structures toppled. With similar...

Testing for Safety & Risks Affecting Operation of HV Cable Terminations, Bushings & Arresters

January 6, 2018 • ARTICLE ARCHIVE, Article of the week, HV/HP Testing, Testing Comments (0)

Not long ago, a HV cable termination operating in a Mediterranean country experienced catastrophic failure, sending high velocity porcelain shards in all directions. The installation happened to be next to a parking lot but fortunately this occurred on a day...

Utilities Chose RTV-Coated Glass Insulators to Resolve Problems in Polluted Environments

January 22, 2018 • ARTICLE ARCHIVE, Glass, Utility Practice & Experience Comments (0)

These days, it is generally accepted that transmission lines passing through areas of heavy pollution, particularly marine pollution, should ideally employ composite insulators. Prevailing wisdom is that this type of insulation offers the best performance...

A Look to the Future of Composite Insulator Technology

January 27, 2018 • ARTICLE ARCHIVE, Insulators Comments (0)

Since the first INMR WORLD CONGRESS held in 1995, by far the most significant development in the field of electrical insulators has been the rapid acceptance of composite insulator technology. Over less than two decades – not that long in the world of power...

INMR advertisers include: