Corona has many advantages and disadvantages. In the correct design of a high voltage overhead line, a balance should be struck between the advantages and disadvantages.
ADVANTAGES
(i) Due to corona formation, the air surrounding the conductor becomes conducting and hence virtual diameter of the conductor is increased. The increased diameter reduces the electrostatic stresses between the conductors.
(ii) Corona reduces the effects of transients produced by surges.
DIS-ADVANTAGES
(i) Corona is accompanied by a loss of energy. This affects the transmission efficiency of the line.
(ii) Ozone is produced by corona and may cause corrosion of the conductor due to chemical action.
(iii) The current drawn by the line due to corona is non-sinusoidal and hence non-sinusoidal voltage drop occurs in the line. This may cause inductive interference with neighboring communication lines.
ADVANTAGES
(i) Due to corona formation, the air surrounding the conductor becomes conducting and hence virtual diameter of the conductor is increased. The increased diameter reduces the electrostatic stresses between the conductors.
(ii) Corona reduces the effects of transients produced by surges.
DIS-ADVANTAGES
(i) Corona is accompanied by a loss of energy. This affects the transmission efficiency of the line.
(ii) Ozone is produced by corona and may cause corrosion of the conductor due to chemical action.
(iii) The current drawn by the line due to corona is non-sinusoidal and hence non-sinusoidal voltage drop occurs in the line. This may cause inductive interference with neighboring communication lines.