These days, the term Corona has become the talk of the town. However, well before this deadly virus, electrical engineers were fighting against another type of Corona, known as Corona Discharge, which, like the virus, is equally undesirable since it adversely affects the quality of power transmission systems. It will be interesting and informative for the readers to know.

Corona discharge or corona effect is caused by the ionization of air surrounding high voltage (132kV and above) transmission lines, inducing a power loss into the system. As a matter of fact, bulk electrical power is transmitted from power houses to main load centers through long-distance high voltage transmission conductors.

The electric field of these conductors ionizes the surrounding air resulting in corona discharge. This corona discharge generates an audible hissing or cracking sound and produces a violet glowing light, which is visible during nighttime at the sharp points, edges and corners of conductors as well as their junction points with towers.

Corona effect significantly reduces the efficiency of power transmission lines, especially during the rainy weather. As such, this has been a point of high concern in electrical engineering. Furthermore, the presence of dirt or roughness of the conductors makes them more prone to corona losses. Hence in big industrial areas having high pollution, the ill effects of corona on the system are more pronounced.

Although the corona losses are individually small, over the time they can add up to significant power loss in high voltage networks. As social distancing is considered the most significant precaution against corona virus, likewise increasing the spacing between conductors decreases the corona effect, subsequently reducing the power loss. If the spacing is made too large, then corona for that region of the transmission line might not occur at all. This is an interesting resemblance in prevention of corona virus and corona discharge.

ENGR. M. HAFEEZ UR RAHMAN,

Islamabad.