Introduction of PLCC
Maintenance & Fault Tracking
Name Of Industry : Rajasthan Rajya Vidyut Prasaran
Location: 132KV CHAMBAL GSS, Jaipur
Reporting Officer: R.P. MEENA
Duration of training : 1th June to 15th July
Department of training :Electronics & Communication
RRVPNL started working from july1957
Sh.Shailendra Agarwal,IAS is the Chairman & MD of
RVPN Provides the pathway for power within whole
This is the body of big organization act , like
public limited companies
It works as electric Power distribution
regulator within the state.
• PLCC is the method of transmitting information
using power network.
• Its equipment are used for point-to-point
communication over high voltage power lines
• Its equipments are used send/receive
• It’s the most economical and reliable method
of communication for medium or long distance.
• The telephone communication system cannot
be directly connected to the high voltage
lines suitably designed coupling devices.
• These usually consist of high voltage
capacitor with polaritical devices used in
conjunction with suitable line matching unit
(LMU) for matching the impedance of line to
that of the coaxial cable connecting the unit
to the PLC transmit-receive equipment.
The signal that can be transmitted over the PLCC
Speech signal (300-2000Hz )
Data signal (2000-3000Hz)
Line matching Unit
Co axial Cable
It is the station where
(modulation)Transmitting , Receiving
(Demodulation ) , Amplification , Filtration are
It is Control Voltage transformer/ Coupling capacitor.
This is used for blocking the high voltage entering
the PLCC Equipment.
This is used at the time of maintenance of LMU.
• Used to protect the system from the damaging
effect of lightening.
• It works as an insulator between light and the
Co axial Cable
This is used for inter connection between
PLCC & L.M.U for carrying the high frequency signal.
The out-put of PLCC is connected to the matching unit
before to the power lines to achieve the proper impedance
matching in between PLCC Equipments and power line.
• Consists of a number choke
coils connected in series.
• It prevents carrier current from
entering to the power equipment.
• Offer negligible impedance to
power frequency & high
impedance to carrier frequency
• The power frequency and radio frequency currents
are sorted by this arrangement
• Carrier currents are prevented to enter station bus by
wave trap & power frequency current is blocked by
coupling capacitor, from the PLC equipment.
• Hence we get power current at the bus & carrier
current at PLC equipment.
• PLCC work on rectified AC or main supply, when
supply goes off, we make use of a device for proper
functioning of PLCC called battery charger.
• This is the device that provide supply to the PLCC
equipment for uninterrupted working.
• It provide DC to the panel by battery.
In fault analysis the faulty devices are checked in this serial or
Telephone or tale operation signal
Cabling low frequency circuit or DC power supply
HF transmission path
The control circuit boards should be inserted far firmly.
The charger should be switch off once in every month.
The battery terminal should be connected first and the
AC input after that.
All mounting bolts should be checked before
No separate wires are needed for
Both communication and power transfer
can be possible on same circuit.
Power lines provides the shortest route
between the power station.
Lower attenuation over long distance.
Implementation cost is reduced.
Reflection are produced on spur lines connected to
high voltage line. This increased attenuation and
create other problem.
High voltage lines have transformer connections,
which attenuate carrier currents.
Noise introduced by power lines is far more than in
case of telephone lines.
PLCC is mainly used for telecommunication, tele-protection and
tele-monitoring between electrical substations through power
In a PLCC system the communication is established through the
The carrier frequency range is allocated to include the audio
signal, protection and the pilot frequency.
The Training was based on communication over
existing power line
Rajasthan Rajya Vidyut Utpadan Nigam Ltd.
Jodhpur dicom vidyut vitran nigam limited
Department of Energy Government of Rajasthan
Jaipur vidhut vitran nigam limited
Rajasthan state load dispatch center