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Corona effect

Corona effect is a phenomenon of ionization and electrical discharge that appears around a conductor carrying high voltage. It is also known as the corona discharge. This effect can be observed in several systems such as power transmission lines, transformers, capacitors, motors, and airplane wings. In the case of power transmission lines, the corona discharge is caused by the ionization of the air surrounding a high-voltage conductor. This ionization occurs when the electric field strength around the conductor exceeds the ionization threshold of air, which is about 30 kV/cm due to this discharge, some of the energy can be lost due to when high voltage is transmitted over long distances and can cause radio interference. This does not only minimize the efficiency of the transmission, but it can also cause real damage to the power lines and the surrounding structures. It also causes radio interference. Moreover, the ionization of air molecules caused by the corona discharge produces ozone which is dangerous to humans and the environment.
Factors contributing to corona effect are high voltage levels which in return causes greater electric field strength. Another factor is the shape and surface of the conductor, rough or irregular shapes increase the corona effect. Taking into consideration the conductor spacing because the closer the two conductors are the stronger the electric field between them. Another important factor is the environmental factors such as Temperature, humidity, and air pressure can affect the ionization threshold of air, and therefore affect the onset of the corona effect. Finally, the design of the transmission line can affect the onset and severity of the corona effect.

Eng Fajer Alenezi