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CORONA AS DEFINED BY IEEE STANDARD 539-1990

Corona Loss
Power lost due to corona process. On overhead power lines, this loss is expressed in watts per meter (W/m) or kilowatts per kilometer (kW/km).

Corona
A luminous discharge due to ionization of the air surrounding an electrode caused by a voltage gradient exceeding a certain critical value.

Corona, Overhead Power LinesCorona occurring at the surfaces of power-line conductors and their fittings under the positive or negative polarity of the power-line voltage.
Continuous CoronaCorona discharge that is either steady or recurring at regular intervals (approximately every cycle of an applied alternating voltage or at least several times per minute for an applied direct voltage).

Corona Pulse
A voltage or current pulse that occurs at some designated location in a circuit as a result of corona discharge.

Burst CoronaCorona mode that may be considered as the initial stage of positive glow. It occurs at a positive electrode with electric field strengths at and slightly above the corona inception voltage gradient. Burst corona appears as a bluish film of velvetlike glow adhering closely to the electrode surface. The current pulses of burst corona are of low amplitude and may last for periods of milliseconds.

Positive Glow
A bright blue discharge appearing as a luminous sheet adhering closely and uniformly to the electrode. Positive glow appears at electric field strengths above those required for burst corona and onset streamers. The corona current of positive glow is essentially pulseless.

Negative Glow
Corona mode that occurs at electric field strengths above those required for Trichel streamers. Negative glow is confined to a small portion of the electrode and appears as a small, stationary, luminous bluish fan. The corona current of negative glow is essentially pulseless.

Streamer Mode
A repetitive corona discharge characterized by luminous filaments extending into the low electric field strength region near either a positive or a negative electrode, but not completely bridging the gap.

Positive Onset Streamers
Streamers occurring at electric field strengths at and slightly above the corona inception voltage gradient. These appear as bright blue “brushes” increasing in length to several inches as the voltage gradient is increased. The associated current pulses are of appreciable magnitude, short duration (in the range of hundreds of nanoseconds), and low repetition rate (less than 1 kHz).

To know know more about the terms used in IEEE, you may refer to IEEE standard 539-1990.

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