Corona is referred to the local glow on a conductor that is subjected to sufficiently high voltage. A local electrical field that exceeds a threshold of about 20-30 kV/cm2, under normal atmospheric conditions, ionizes air molecules releasing electrons and anions. Electrons that gain energy from the electric field tend to revert to their original stable state while releasing that energy in the form of light. The glowing is found locally around the source because of the insulation barrier and due to the fact that the electrical field decays rapidly with distance.

Corona triggers many modes of degradation, all at once, and therefore should be monitored. 

Corona creates: 

• Audible noise 
• Acids both organic (oxalic) and inorganic (nitric) in the presence of moisture 
• Ozone 
• Radio and TV reception interferences 
• UV light. 

Corona is a destructive factor of the electrical grid and a highly reactive degrading agent leading to erosion and decomposition of insulators and affecting their mechanical and electrical properties.

Application fields: 

• Electrical Utilities routinely inspect high & medium (Hi/Med) voltage installations, see and foresee faults
• Heavy Industries maintaining reliability of their own substations & Hi/Med voltage installations
• Manufacturing Industries performing QA and compliance assessment of products for the elec. grid
• HV Laboratories testing failure & aging processes
• Service Contractors providing inspection services
• Workshops performing conformance testing of rotating machines and other
• Data Centers ensuring uninterrupted ongoing electricitysupply
• Mines & Refineries ensuring uninterrupted electricity supply and sparks free conditions
• High Speed Electrical Trains inspecting H/M Voltage installations to ensure mass transportation safety and operation

For more information about technology and available products please contact HVP.