Lhotser

Shanghai, China

We are offering corona rings. Corona discharge is an electrode-outer air current flow that happens (among other) in high-voltage power lines. One way to reduce corona discharge is using corona rings - a ring made of thick metal rod positioned orthogonal to the wire, earthed and mounted to the power line post. Corona discharge damages insulators and may produce breakdown products which can cause catastrophic insulation failure. If electric field at a certain point in air is strong enough, electrons will be stripped from the atoms and make the air a conductive plasma instead of an insulator. An object with high voltage and a small curvature (wire, sharp points) enables a field of enough high strength, forming a conductive layer of air, which is then surrounded by normal insulating air. In this case the conductive layer can increase in size (usually in one direction) until it forms a complete conductive path to another object, and then a huge arc-shaped current flow. Even a non-arc-shaped field can form a corona discharge. For that a conductive layer of plasma stops expanding and stays around the wire, ions in the plasma layer are repelled into neutral air and drift slowly in the air until discharged on another object, which is still a current flow yet much smaller. A useful secondary role is to reshape the electric field distribution across a stack of insulators so that the potential drop per insulator is more even, thereby reducing the breakdown stresses on the insulator with highest voltage drop.