Corona ring

A corona ring is an annular element made ​​of electrically conductive material, usually metal, which is used to control the electric field strength at certain points of an electrical line.

Principle

The corona ring is a two-dimensional simplification of the Faraday cage dar. accordance with the laws of electrostatics is the interior of such a ring almost free of electric fields, so no corona discharges can occur there.

Application

The corona ring on an insulator causes the sometimes sharp edges of the fasteners on live end of the insulator for the electrical field have hardly any significance, as these components are within the corona ring in a nearly field-free region. Thus occur at their edges to almost no peak discharges.

Corona rings can be found, for example,

• On the insulators of high voltage cables with operating voltages above 100 kV.
• To the strain insulators even more radiant transmission towers, where high stresses occur.
• At marker lamps for air traffic control on high voltage lines.