When a high or extra high voltage transmitted in a
transmission line, due to magnetic effect on the core of
the conductor all most all electronics pass on the surface
of the conductor. So the air outside the conductor surface
becames conducive and looks bluish and due to dielectric
breakdown of air a hissing noise comes from surrounding,
Called as corona !
Due to corona OZONE formation on the outside surface of the
conductor. The effect of this to the power system is called
as corona effect.
It generally occure at high voltage transmission. When
dielectric voltage becomes more than 30v\cm . than it
ionise the sorrounding air . So the air outside the
conductor surface becames conducive and looks bluish and
due to dielectric breakdown of air a hissing noise comes
from surrounding, Called as corona !
corona appears due to the ionizing of the surronding air
due to the electromagnetic fields surronding the cable it
has two names dark corona and corona and it a appear as
redd bluish glue it has adv and dis adv.
it generally occure at high voltage overhead transmission
lines,when the dielectric voltage becomes more than
30v/cm.the the surrounded air becomes ionized meaning
conductive and hissing noise issued due to the saturated
air by electronic, and a violet color could be seen.their
are some advantages of this phenomena we can get,one of
theme in cold region while the ice accumulate over the T.L
the heat that emitted due to the accident of electronic
dissolve the ice otherwise may the WEIGHT OF T.L becomes so
heavy and break the structures of the O.H.T.L.
when air is passed through conductor having high electric
field, velocity of electrons increases so this electrons
collide with other atom and leads to ionisation in air at
certain stage breakdown occur between the conductor with
some violet glow which produce ozone gas with some hissing
in our 6.6kv motor feeder[it is having two sources from
Bus A&B] earth fault relay is acting, we checked CBCT
connection and cable meggerd values found very good still
earth fault acting during first two are three start after
that it will hold. please clarify what was the reason. if
same motor is starting from other Bus-A it will start.