What is corona discharge??

Corona discharge(or corona effect) is a discharge caused by the ionization of air surrounding a conductor. corona effect is only observed in the high voltage systems like transmission lines, cathode ray tubes, etc. corona effect also produces a humming noise and produces the violet color on the conductors. it also causes the formation of ozone gas and many other gases that are toxic to living beings.

Corona Discharge

As you all know the air is not a pure insulator and can allow the passage of electric current at high voltage as we have seen in spark-gap Tesla coil where after achieving breakdown voltage electric spark is created between two points.

Suppose we have two parallel conductors separated by air are supplied with high voltage. due to this, both conductors will create their own electric field. the electrons in the air will experience a force due to the electric field. if the electric field intensity is high it will easily breakdown dielectric properties of air and spark of violet color will generate. the violet color is seen in the places where filed intensity is high, which means near the conductor. if the conductor is rough corona effect will increase. As corona discharge causes the generation of high-frequency spark, they interfere with other electronic devices like CRT television. corona discharge also causes power loss during the transmission of high voltage electricity.

How to overcome this problem

The corona effect is an unwanted effect in the power system. we can reduce the corona effect by following methods

• By increasing the diameter of conductors.
• By using bundled conductors instead of a single conductor.
• By maintaining a perfect distance between conductors.
• By using corona rings.