Lightning Arresters or Surge Arresters are always connected
in Shunt to the equipment to be protected, they provide a
low impedance path for the surge current to the ground.
Wave trap is a parallel tuned inductor - capacitor 'tank'
circuit made to be resonant at the desired communication
It is the effort to utilize the same transmission line
between two substation for the purpose of communications.
At this communication frequencies the tank ckt provides
high impedance and does not allow to pass through them &
onto the substation bus & into transformers.
Lightening Arrester is connected in shunt with the lines so
that is protects from lightening.
when ever the lightening occurs, there is a voltage around
some thousands of voltage appear on line (3500V to 5000V)
for a fraction of seconds(25 to 30micro sec.s) which is more
than enough to damage all the equipment in the grid
connected to it. so when a lightening arrester is connected
then is provides low resistance path such that all that high
voltage is directed towards the earth resulting the
protection of all the equipments connected to the grid.
To protect human life and property, design engineers have to
install lightning protection systems on every GRID
SUB-STATION . The main function of the system is to capture
the lightning stroke, over voltage and then conduct
discharge current safely to the ground. Since there are 100
lightning discharges to the ground every throughout the
world, installing lightning protection systems are very
important for safety to human life and station
a wawe trap is the device which trap the high frequency
signals to enter into substation.
As XL =2 Pi w f L as impedence is directly proprtional to
frequency thus provide high impedane for high frequency
(carrier frequency)& vice versa.
lightning arrester prevent the substation from lightning
impulse, under normal condion impedace of air gap is high
enough for the voltage i.e no discharge, in case of
lightning high voltage appears around air gap and cause a
discharge through air and go to ground and prevent from