2. Rajasthan Rajya Vidyut Prasaran
Nigam Limited (RVPNL)
Rajasthan Rajya Vidyut Prasaran Nigam Limited
(RVPNL) is a company of Rajasthan State Electricity
Board (RSEB) established by government of
Rajasthan.
Aim of RVPNL is to provide reliable Xmission
service to customers.
132 KV G.S.S., Bhadra (Hanumangarh) is a part
of RVPNL and power comes from SSTPS.
3. Components of A Sub-Station
1.Primary power lines 2.Ground wire 3.Overhead lines
4.Transformer for measurement of electric voltage 5.Disconnect
switch 6.Circuit breaker 7.Current transformer 8.Lightning
arrester 9.Main transformer 10.Control building 11.Security
fence 12.Secondary power lines
5. Lightning Arrester (L.A.)
Lightning Arrester is a
protective device which
provides protection against
high voltage surges.
A lightning arrester has
two terminals viz a high
voltage terminal and a
ground terminal.
10. Power Line Carrier Communication
For exchange of data and transfer of messages
between substations, voice communication is
necessary. For this purpose high frequency carrier
current is transmitted over same transmission line on
which power is transmitted. Hence this
communication is called as power line carrier
communication .
12. Isolator
It isolates the devices
from live line when
there is a maintenance.
It operates when there
is no load.It is also used
to change bus bar line
from main to reserve or
vice versa.
13. Current Transformer (C.T.)
Current Transformer is
used to measure high value
of current.
C.T. ‘s secondary is
connected to relay to
protect the system
against overcurrents.
14. Circuit Breaker
Today, two most popular
circuit breakers are used
in sub-stations which are:
Vacuum Circuit Breaker &
SF6 Circuit Breaker.
Oil and Air Blast circuit
breaker was used in earlier
decades.
15. Bus Bar
It is a metallic bar
which has high current
carrying capability.
Bus bar is made
from ‘Cu’ and ‘Al’.
Its function is to
carry electricity from
line to switchyard or
vice-versa.
16. Power Transformer
Transformer is a
static device that transfers
electrical energy from one
electric circuit to another
electric circuit by means of
a common magnetic circuit.
Transformer can link
two or more electric circuits.
17. Main Parts of Power Transformer
(a) Core
(b) Windings (H.V. winding, I.V. winding & L.V. winding)
(c) Tap changer
(d) Main tank
(e) Conservator Tank
(f) Buchholz Relay
(g) Dehydrating Breather
(h) Oil Temperature Indicator
(i) Winding Temperature Indicator
19. Protective Relays
Protective Relay is
a sensing device and
is designed to detect
operating conditions
on an electric circuit.
It trips the circuit
breaker when fault is
detected.
