PLCC Summer Training Report Summary

i
S.K.CHAUDHARY EDUCATIONAL TRUST’S
SHANKARA INSTITUTE OF TECHNOLOGY
KUKAS, JAIPUR
DEPARTMENT OF ELECTRONICS &COMMUNICATION
SESSION (2015-2016)
A SUMMER TRAINING REPORT
SUBMITTED IN PARTIAL FULFILLMENT FOR AWARD OF DEGREE OF
BACHELOR OF TECHNOLOGY
RAJASTHAN TECHNICAL UNIVERSITY, KOTA (RAJASTHAN)
RAJASTHAN RAJYA VIDYUT PRASARAN
NIGAM LIMITED, JAIPUR
DURATION OF TRAINING:- 60 DAYS
DATE OF TRAINING:-25.05.2015 TO 25.07.2015
SUBMITTED TO SUBMITTED BY
Mr. ASHUTOSH MISHRA RAMANAND SAGAR
H.O.D B.TECH (VIITH
SEM)
(ECE DEPARTMENT) (12ESIEC047)

ii
PREFACE
The objective of a practical training is to learn something about industries practically and to
be familiar with a working style of a technical worker to adjust simply according to industrial
environment. As a part of academic syllabus of four year degree course in ECE, every student
is required to undergo practical training of 60 days. We are student of 3rd year ECE and this
report is written on the basis of practical knowledge acquired by our batch of 4 students
during the period of practical training taken at PLCC section of 132 KV, Chambal G.S.S
(Grid Substation) Jaipur.
This report deals with the equipments their relation and their general operating principle.
Sincere efforts have been made to present this report on PLCC with relevant diagrams and
proper description.
Inspire of all our best efforts, some unintentional errors might have eluded, it is requested to
neglect

iii
ACKNOWLEDGEMENT
I am grateful to Mr. R. P. Meena (Assistant engineer) for providing me an opportunity to
work as a trainee in PLCC section of Chambal G.S.S. I am thankful to Mr. Rajesh Chander
Singh (R.M-II) all other technical staff of PLCC of their valuable practical guidance and
their keen interest in my training.
I am very grateful to Mr. Ashutosh Mishra (HOD of ECE Department) to give me
opportunity to go under training at PLCC SECTION 132 KV, CHAMBAL G.S.S.,
JAIPUR as I was very enthusiastic about this. I am also very thankful to our seminar in-
charge Mr. Rajesh Kanwadia(Assistant professor of ECE Depatment and Ms. Shweta
Agarwal(Assistant professor of ECE Department).
I am thankful to my batch- mate and as well as my training colleague.
RAMANAND SAGAR

iv
INDEX
S.NO. TOPIC PAGE NO.
Chapter 1 INTRODUCTION TO PLCC………………………………………………… 1-2
Chapter 2 HISTORY………………………………………………………………………3-3
Chapter 3 BASIC PRINCIPAL OF PLCC………………………………………………..4-6
Chapter 4 EQUIPMENTS USED IN PLCC………………………………………………..7
4.1 OUTDOOR EQUIPMENTS…………………………………………………..7
4.2 INDOOR EQUIPMENTS……………………………………………………..7
Chapter 5 MAIN COMPONENTS OF PLCC……………………………………………...8
5.1 COUPLING CAPACITOR……………………………………………………8-9
5.2 LINE TRAP-UNIT/ WAVE TRAP…………………………………………...10
5.3 TRANSMITTER AND RECIVER……………………………………………10
5.4 HYPBRIDS AND FILTER…………………………………………………….11
5.5 LINE TUNERS………………………………………………………………..11
5.6 PROTECTION AND EAETHING OF COUPLING EQUIPMENTS………..12
5.7 LIGHTNING ARRESTER…………………………………………………….12
5.8 DRINAGE COIL………………………………………………………………13
5.9 LINE MATCHING UNIT……………………………………………………..13
5.10 CO-AXIAL CABLE…………………………………………………………13
Chapter 6 BASIC COUPLING ARRANGEMENT………………………………………..14
6.1 TYPES OF COUPLING……………………………………………………….15
6.1.1 PHASE TO GROUND COUPLING…………………………………………15
6.1.2 PHASE TO PHASE COUPLING……………………………………………15
6.1.3 INTERLINE COUPLING……………………………………………………16
6.2 COMPARISION OF PHASE TO PHASE AND GROUND COUPLING…17-18
Chapter 7 INDOOR EQUIPMENTS……………………………………………………….19
7.1 RTU (REMOTE TERMINAL UNIT)…………………………………………19
7.2 EPAX 2003(PLCC)…………………………………………………………….19
7.3 BATTERY BANK………………………………………………………………20
Chapter 8 CONSTRUCTION OF PLCC……………………………………………….21-22

v
Chapter 9 SPECIFICATION OF PLCC……………………………………………………23
9.1 GENERAL…………………………………………………………………….23
9.2 TRANSMITTER………………………………………………………………23
9.3 TRUNK DIALING……………………………………………………………23
9.4 POWER SUPPLY……………………………………………………………..24
9.5 CAUTION……………………………………………………………………..24
Chapter 10 GENERAL DISCRIPTION OF PLCC EQUIPMENTS……………………….25
10.1 TELEPHONY AND TELE-OPERATION…………………………………..25
10.2 TELE-PROTECTION SIGNALS……………………….………………25-26
Chapter 11 APPLICATION OF ETI EQUIPMENTS……………………………………...27
11.1 PLC EQUIPMENTS AND COMBINED UNIT…………………………….27
11.2 REMOTE AT MULTIPLEXER CONNECTED BY A LONG CABLE…….28
11.3 BRIEF CHARACTERSTICS……………………………………………….28
11.4 REMOTE AT MULTIPLEXER CONNECTED BY A SHORT LINE……..28
11.5 PROTECTION SIGNALLING OVER PLCC EQUIPMENT………………28
11.6 REPEATERS…………………………………………………………………28
Chapter 12 MODE OF OPERATION………………………………………………………29
12.1.1 TELEPHONE FASCILITIES……………………………………………..29
12.1.2 COMPRESSOR AND EXPANDER………………………………………29
12.1.3 FOR WIRE HAND/ EMERGENCY CALL………………………………29
12.1.4 SERVICE TELEPHONE………………………………………………….30
12.1.5 TELE-OPERATION SIGNAL…………………………………………….30
12.1.6 SIGNAL BOOSTING……………………………………………………..30
12.2 FAULT ANALYSIS & TEST PROCEDURES………………………….30
12.2.1 TEST EQUIPMENTS……………………………………………………..31
12.2.3 FAULT ANALYSIS………………………………………………………..31
Chapter 13 BATTERY CHARGER………………………………………………………..32
13.1 GENERAL DESCRIPTION…………………………………………………32
13.2 TECHNICAL SPECIFICATION…………………………………………….33
13.3 FLOAT CHARGER SECTION………………………………………………33
13.3.1 CIRCUIT DESCRIPTION…………………………………………………33
13.3.2 FUSE FAIL ALARM……………………………………………………….34

vi
13.4 BOOST CHARGER………………………………………………………….34
13.4.1DESCRIPTION OF CIRCUITS……………………………………………34
13.4.2OPERATION OF CHARGER………………………………………….34-35
Chapter 14 APPLICATION OF PLCC……………………………………………………36
Chapter 15 ADVANTAGE AND DISADVANATAGE OF PLCC………………………37
Chapter 16 PRECAUTIONS & MAINTENANCE………………………………………38
Chapter 17 CONCLUSION………………………………………………………………39
Chapter 18 REFRENCES…………………………………………………………………34

vii
LIST OF FIGURES
S.NO TOPICS PAGE NO.
FIG3.1 AM and FM.............................................…………………………….............06
FIG3.2 PLCC indoor Equipment...................................................................................07
FIG3.3 PLCC outdoor Equipment…………….......…….............................................07
FIG 3.4 Typical PLCC System..........…………...........................…….........................08
FIG 5.1 PLCC component-coupling capacitor...................……...................................11
FIG 5.2 Wave Trap...................................................................................……….........11
FIG 5.3 Transmitter and Reciver...............……………...........................………........12
FIG 5.4 Protection and Earthing of Coupling Equipments............................................14
FIG 5.5 Lightning Arrester……….………...................................................................14
FIG 6.1 Basic coupling arrangement......................................………….......................16
FIG 6.2 Phase to Ground Coupling...............................................................................17
FIG 6.3 Phase to Phase coupling...................................................................................18
FIG 6.4 Inter Circuit Coupling......................................................................................19
FIG 7.1 Indoor Unit.....................................................................………......................21
FIG 13.1 Battery Charger................................................................................................34
FIG 13.2 Block Diagram of Float snd Boost Charger.....................................................34

viii
INTRODUCTION OF RSEB
The history of power development in Rajasthan goes back to the year 1949, when 19 princely
states merged to form Rajasthan. At that time,
Electric power was confined to very few towns and electricity was considered a luxury. The
total number of towns and villages electrified at that time did not exceed 42 and the installed
generating capacity was only 13.27 MW. However, with the formation of Rajasthan State
Electricity Board (RSEB) on 1st July 1957, power sector in Rajasthan received priority and
power projects began to mushroom all over State.
Rajasthan State Electricity Board Companies Government of Rajasthan on 19th July
2000,issued a gazette notification unbundling Rajasthan State Electricity Board into five
different companies so that board will run efficiently.
1. Rajasthan RajyaVidyutUtpadan Nigam Ltd.(RVUN), the generation Company.
2. Rajasthan Rajya Vidyut Prasaran Nigam Ltd.,(RVPN), the transmission Company.
3. Jaipur Vidyut Vitran Nigam Ltd.,(JVVNL) , a regional distribution company.
4. Ajmer Vidyut Vitran Nigam Ltd.(AVVNL) a regional distribution company.
5. Jodhpur Vidyut Vitran Nigam Ltd.(JDVVNL) a regional distribution company.
Rajasthan State Electricity Board Companies Functions
The Generation Company owns and operates the thermal power stations at Kota and
Suratgarh, Gas based power station at Ramgarh, Hydel power station at Mahi and mini hydel
stations in the State. The Transmission Company operates all the 765kV, 400kV, 220 kV and
132 kV electricity lines and system in the State. The three distribution Companies operate and
maintain the electricity system below 132kV in
the State in their respective areas.[1]

ix
CHAPTER 1
INTRODUCTION TO PLCC
(POWER LINE CARRIER COMMUNICATION)
The basic idea of this project into get benefit by transmitting /receiving data as well as power
through HF (high frequency)cables. Power Line Communication (PLC) is a communication
technology that enables sending data over existing power cables. This means that, with just
power cables running to an electronic device (for example) one can both power it up and at
the same time control/retrieve data from it in a half-duplex manner.
Use of PLCC in modern electrical power system is mainly for telemetry and tele control. Tele
means remote. Telemetry refers to science of measurement from remote location. Different
types of data transmission system can be used depending upon the network requirement and
conditions.
Main data transmission system for telemetry and tele-control are:
1. Use of telephone lines
2. Use of separate cables
3. Power Line carrier communication
4. Radio wave micro wave channel [2]
PLCC is said to be backbone of Electrical transmission system. For large power system
power line carrier communication is used for
1. Speech transmission
2. Data transmission and
3.Protection of transmission lines.
Carrier current has a frequency range of30 to200 kHz in USA 80 to 500 kHz in UK,24 kHz
to 500 kHz in INDIA.
NEED OF PLCC
1. To cope up with ever increasing size of power grid
2. Need for economic and reliable means of intercommunication between various
generating station, substation and control room
3. Avoid dependence of busy telephone lines
Each end of transmission line is provided withidentical PLCC equipment consisting

x
ofequipment:
1. Transmitters and Receivers
2. Hybrids and Filters
3. Line Tuners
4. Line Traps
5. Power amplifier
6. Coupling capacitor

xi
CHAPTER 2
HISTORY
The idea of using an existing medium to send the communication signals is as old as the
telegraph itself. But it had not been possible until the recent decades. The first significant step
in the field was when two patents were issued to American Telephone and Telegraph
Company in the name of 'Carrier Transmission over Power Circuits' in 1920. After four years
later in 1924 two other patents were filed for the systems transmitting and receiving
communication signals over three phase power lines.
Harsh characteristics of the power cables were the key problem in further development.
Researchers were involved to overcome the unpredictable characteristics of the power lines.
Since the early 1980, spread spectrum power line communication was the main focus of the
research. This technology is now developed far better than that initial improvement and is
promising a reliable utilization in home automation and security systems.
This technology has been in wide use since 1950 and was mainly used by the grid stations to
transmit information at high speed.[3]

xii
CHAPTER 3
BASIC PRINCIPAL OF PLCC
Power-line communications systems operate by adding a modulated carrier
signal on one conductor, on two conductors or on all three conductors of a high-
voltage AC transmission line. Different types of power-line communications use
different frequency bands. Since the power distribution system was originally
intended for transmission of AC power at typical frequencies of 50 or 60 Hz,
power wire circuits have only a limited ability to carry higher frequencies. So,
allotted frequencies range for this purpose is from 24 to500 kHz, with
transmitter power levels up to hundreds of watts.[4]
To carry out this communication there is a need of modulation. For PLCC,
generally amplitude modulation (AM) is used.
Fig-3.1( AM and FM)
In amplitude modulation, the amplitude (signal strength) of the carrier wave is
varied according to modulating signal. Sometimes frequency modulation is also
used if transmitting medium is optical fiber instead of coaxial cable.[5]
PLCC has some equipment inside the PLCC room and some part in switch yard.

xiii
Fig- 3.2 (PLCC indoor Equipment)
Carrier signal which is generated by oscillator is modulated with message signal
with the help of modem, there after it is allowed to pass through band pass
filter; output of band pass filter is amplified before transmission via hybrid
section, this modulated signal is transmitted through high frequency co-axial
cable to yard.
Fig- 3.3 (PLCC outdoor Equipment)
Since telephone communication system cannot directly connected to the high
voltage lines suitably designed coupling devices have therefore to be employed.
These usually consists of high voltage capacitor or capacitor with polarized
devices used in conjunction with suitable lines matching unit (LMU’s) for
matching the impedance of line to that of the coaxial cable connecting the unit
to the PLCC transmit-receive equipment.
To sectionalize the transmission network and protect against failures, a "wave
trap" is connected in series with the power (transmission) line. They consist of
one or more sections of resonant circuits, which block the high frequency carrier

xiv
waves (24 kHz to 500 kHz) and let power frequency current (50 Hz – 60 Hz)
pass through. Wave traps are used in switchyard of most power stations to
prevent carrier from entering the station equipment. Each wave trap has
alighting arrester to protect it from surge voltages.
A coupling capacitor is used to connect the transmitters and receivers to the high
voltage line. This provides low impedance path for carrier energy to HV line but
blocks the power frequency circuit by being a high impedance path. The
coupling capacitor may be part of a capacitor voltage transformer used for
voltage measurement.
Fig-3.4( Typical PLCC system)

xv
CHAPTER 4
EQUIPMENTS USED IN PLCC
4.1EQUIPMENTS OF SUB-STATION OR OUTDOOR EQUIPMENT
1) Lightning arrester
2) Wave traps.
3) Drainage coils
4) LMU
5) Earthing switch
6) CC/CVT
7) Co-axial cable
4.2INDOOR EQUIPMENT
1) PLCC panel
2) Battery bank
3) Battery charger
4) EPBAX
5) RTU
6) Modem

xvi
CHAPTER 5
Main Components of PLCC
5.1 Coupling Capacitor
Couples high frequency carrier with power line (4000-10000pF)
Fig-5.1(PLCC component - Coupling Capacitor)
Coupling capacitor connects the carrier equipment to the transmission line. The coupling
capacitor’s capacitance is of such a value that it offers low impedance to carrier frequency
(1/ωC) but high impedance to power frequency (50 Hz).
For example 2000pF capacitor offers 1. 5MΩ to50 Hz but 150Ω to 500 kHz.
Thus coupling capacitor allows carrier frequency signal to enter the carrier equipment.
To decrease the impedance further and make the circuit purely resistive so that there is
nonreactive power in the circuit, low impedance is connected in series with coupling
capacitor to form resonance at carrier frequency.[2]
5.2 Line trap Unit /WAVE TRAP-
Do not allow the transmitted HFcarrier to enter inside the sub-station. without line trap HF
carrier get bypassed to some other line on the same bus bar and may leak to ground.

xvii
Fig-5.2 (WAVE TRAP)
The carrier energy on the transmission line must be directed toward the remote line terminal
and not toward the station bus and it must be isolated from bus impedance variations. This
task is performed by the line trap. The line trap is usually a form of a parallel resonant circuit
which is tuned to the carrier energy frequency.
A parallel resonant circuit has high impedance at its tuned frequency, and it then causes most
of the carrier energy to flow toward the remote line terminal. The coil of the line trap
provides a low impedance path for the flow of the power frequency energy.
Since the power flow is rather large at times, the coil used in a line trap must be large in terms
of physical size. Hence a line trap unit /Wave trap is inserted between bus bar and connection
of coupling capacitor to the line. It is a parallel tuned circuit comprising of inductance (L) and
Capacitance (C).It has low impedance (lessthan0.1)for power frequency (50 Hz) and high
impedance to carrier frequency .This unit prevents the high frequency carrier signal from
entering the neighboring line.
Tuning Device (T.D.):
These are used with high voltage, high stability mica capacitors with no losses. For lower

xviii
voltage class of tuning units (with impulse test voltage rating up to 40 KV)
Polystyrene capacitors are used by some manufactures. For higher voltage class of
tuning units with impulse test voltage rating up to 150 KV, capacitors with mineral oils
impregnated paper dielectric are used which rare
similar in construction to coupling capacitors all types are mounted in epoxy resin.
Single frequency traps have a single and double frequency traps and double tuned parallel
resonant circuits.
All the elements belonging to the tuning circuits are usually mounted in a common housing,
which can be resolved and substituted with another similar tuning device to resonate trap to a
different frequency.[2]
5.3 Transmitters and Receivers:-
The carrier transmitters and receivers are usually mounted in a rack or cabinet in the control
house, and the line tuner is out in the switchyard .This then means there is a large distance
between the equipment and the tuner, and the connection between the two is made using a co-
axial cable.
Fig-5.3(PLCC component-Transmitters and receivers)
The coaxial cable provides shielding so that noise cannot get into the cable and cause
interference. The coaxial cable is connected to the line tuner which must be mounted at the
base of the coupling capacitor. If there is more than one transmitter involved per terminal the
signal must go through isolation circuits, typically hybrids , before connection to the line
tuner.[2]

xix
5.4 Hybrids and Filters :-
The purpose of the hybrid circuits is to enable the connection of two or more transmitters
together on one coaxial cable without causing intermediation distortion due to the signal from
one transmitter affecting the output stages of the other transmitter. Hybrids may also be
required between transmitters and receivers, depending on the application. The hybrid circuits
can, of course, cause large losses in the carrier path and must be used appropriately. High
/low -pass and band-pass networks may also be used, in some applications, to isolate carrier
equipment from each other.[2]
5.5.Line Tuners:-
The purpose of the line tuner in conjunction with the coupling capacitor is to provide low
impedance path for the carrier energy to the transmission line and a high impedance path to
the power frequency energy.
The line tuner /coupling capacitor combination provides a low impedance path to the power
line by forming a series resonant circuit tuned to the carrier frequency.
On the other hand, the capacitance of the coupling capacitor is high impedance to the power
frequency energy. Even though the coupling capacitor has high impedance at power
frequencies, there must be a path to ground in order that the capacitor may do its job. This
function is provided by the drain coil, which is in the base of the coupling capacitor. The
drain coil is designed to be low impedance at the power frequency and because of its
inductance it will have high impedance to the carrier frequency.
Thus the combination of the line tuner, coupling capacitor, and the drain coil provide the
necessary tools for coupling the carrier energy to the transmission line and blocking the
power frequency energy. One last function of the line tuner is to provide matching of
impedance between carrier coaxial cable, usually 50 to 75 ohms, and the power line which
will have an impedance of 150 to 500ohms.[2]

xx
5.6. Protection and earthing of couplingequipment:-
Over voltage can be caused due to lightning, switching and sudden loss of load etc.
They produce stress on coupling equipment and line trap units. Non linier resistor in series
with protective gap is connected across the line trap unit and inductor of coupling unit.
The gap is adjusted to spark at a set value of over voltage.
Coupling unit and PLCC equipment are earthed through a separate and dedicated system,
so that ground potential rise of station ear thing system does not affect the reference voltage
level /Power supply common ground of the PLCC equipment.[2]
Fig-5.4 Fig-5.5
5.7.Lightning arrester :
A lightning arrester (in Europe: surge arrester) is a device used on electrical power systems
and telecommunications systems to protect the insulation and conductors of the system from
the damaging effect of lightning. The typical lightning arrester has a high-voltage terminal
and a ground terminal. When a lightning surge (or switching surge, which is very similar)
travels along the power line to the arrester, the current from the surge is diverted through the
arrestor, in most cases to earth.
5.8.Drainage coil :

xxi
When supply is given, all equipments start working. Wave trap block high frequency signals
like 200khz and pass low frequency signal like 50hz and coupling capacitor passes the high
frequency signals of 200 kHz and blocks low frequency signal of 50 Hz. During all this
process if any leakage current flows due to any distortion, then this drainage coil arrests all
leakage current and ground it so that it does not cause any harm to the network.
5.9 Line Matching Unit:-
The out-put of PLCC is connected to the line matching unit before to the power lines to
achieve the proper impedance matching in between PLCC Equipments and power line.
LMU is a composite unit consisting of Drain Coil, Isolation transformer with Lightning
Arrester on its both the sides, a Tuning Device and an earth switch. Tuning Device is the
combination of R-L-C circuits which act as filter circuit. LMU is also known as Coupling
Device. Together with coupling capacitor, LMU serves the purpose of connecting effectively
the Audio/Radio frequency signals to either transmission line or PLC terminal and protection
of the PLCC unit from the over voltages caused due to transients on power system.
5.10 CO-AXIAL CABLE :-
This is used for inter connection between PLCC & L.M.U. for carrying the high frequency
signal.
CHAPTER 6
BASIC COUPLING ARRANGEMENT
The power frequency and radio frequency currents are sorted by this arrangement.
Carrier currents are prevented to enter station bus by wave trap and power frequency current
is blocked by coupling capacitor, from the PLC equipment.

xxii
Hence we get power current at the bus and carrier current at PLC equipment.
Earth switch is used at the time of maintenance of LMU.
Lightening Arrestor is used to protect the system from the damaging effect of lightening.
Drainage coil has a pondered iron core serves to ground the power frequency
charging to appear in the output of the unit.
Fig-6.1 (Basic coupling arrangement)
6.1TYPES OF COUPLING
6.1.1Phase to ground coupling

xxiii
Fig-6.2 (Phase to Ground Coupling)
This figure describes that the wave trap and coupling capacitors are all connected to one
conductor of the power line. The remaining two conductors, though not directly connected to
the line carry a portion of the returning carrier current because these two conductors do not
have wave traps, a portion of the carrier energy is 1 lost. Also radiation losses are gone high
as earth forms a part of the circuit and the noise pickup is correspondingly higher. The
method of connecting is inefficient and the connection at the receiving end cannot be made to
match the line perfectly. This is because the impedance of the line cannot be calculated
correctly as it depends partly on the soil conductivity enroot the line which varies from place
to place and time to time and partly on station switching condition.
6.1.2 Phase to phase coupling

xxiv
Fig-6.3 (Phase to Phase coupling)
This type of coupling was formally being used to improve the reliability of communication
case of breakage of one of the coupled conductors. The system used double the number of
wave traps and coupling capacitors used in phase to ground and hence is costlier. This
coupling capacitor at each and have the line are connected in parallel to the LMUs.
Through this type of coupling there is increment in the reliability of communication, the
attenuation, the interference from radio transmission and monitoring possibilities are all
higher than those of phase to ground coupling. Hence this type of coupling has been
discontinued and super sided by the phase-to-phase coupling system.
6.1.3 Inter linecoupling.
Fig-6.4( Inter circuit coupling)
This is the same as phase to phase coupling but with the difference that the two conductors
used for communication belong to two-different power circuits carrier on common towers.
This type of coupling is not employed where the two circuits are carrier on two separate sets
of towers as it then behaves more like a double phase to ground coupling and is found to be
impracticable.
This type of coupling is even more reliable than phase-to-phase coupling on the same circuit
than it permits operation with one of the two circuits opened out and founded for maintenance

xxv
purpose.
Inter phase or inter systems coupling are always employed on 220KV and 400KV lines where
the interference levels are therefore also used on very long 110KV lines where attenuation
becomes a problem. This type of coupling permit higher reliability of operation under breaker
conductor conditions and are always employed where carrier line protection systems are
employed.
6.2.Comparison of phase to phase and phase to ground coupling:-
The phase to phase coupling has the advantage of requiring only half the number of wave
traps and coupling capacitors in comparison to phase-to-ground. But it is inferior to many
respects as would be evident from the following points:-
1. The phase-to-ground coupling has higher attenuation and unlike phase-to-phase
coupling, the attenuation varies with station switching conditions.
2. The variation of attenuation function with changes in weather condition is greater in
phase-to-ground coupling.
3. Reflection and echoes due to mismatch difficulties are much greater in phase-to-
ground coupling.
4. Signal-to-noise ratio is poorer due to longitudinal noise voltage induced in the line. In
phase-to-phase coupling the noise voltage tend to coupled conductors, which oppose
each other in the circuit.
5. Radiation from phase-to-ground case is about double than that in the other case.
6. A break or fault of some other kind will hamper the transmission in phase-to-ground
coupling much more seriously than in the other case.
Hence, phase-to-ground coupling is used due to its cheapness, especially when frequency
used and distance to be covered is suitable, and radiation not particularly objectionable, as
may be the situation in sparsely populated areas.

xxvi
CHAPTER 7
INDOOR EQUIPMENTS
Fig-7.1(Indoor unit)
7.1.R.T.U (REMOTE TERMINAL UNIT) :
• Interface with the electrical network to be monitored/controlled.
• Collects, filters& processes the power system data and transmits it to the control center.
• Receives the control commands from the control centre.
7.2.EPAX 2003(PLCC):-
The EPAX system 2003 (PLCC version) is an advanced, state of art, stored program
microprocessor controlled exchange, using 8-bit microprocessor. The control functions are
implemented with digital hardware and voice switching is done with TDM technique. The
microprocessor control ensures most reliable switching because the system employs only
electronic circuit. It eliminates periodic preventive maintenance and makes system noiseless
unlike conventional electromechanical exchanges. The PA2003 (PLCC) system accepts
decaying dialing pulses and is therefore compatible with rotary dialing instruments or pulsing

xxvii
type button telephone instruments. The PA2003 (PLCC) system has been specially designed
to be connected to be connected to another PAX through power line carrier communication
equipment. This system is intended to be a direct replacement for the electromechanical
exchange now in use in power generation system and industries. The exchange can interface
directly with PLCC terminal on one hand and the existing telephone sets all the others. Hence
the exchange software has been designed to meet all the existing needs of the presently used
electromechanical exchange.
7.3.BATTERY BANK:-
 In case main supply is off, battery bank supply required amount of supply power.
 Now a day care-free VARLA BATTERR is used.
 VARLA stands for

xxviii
CHAPTER 8
CONSTRUCTION OF PLCC
The PLC equipment, built in MODULE ELECTRONIC SYSTEM (MES) is especially
compact. For all equipment variations, the single channel equipment ETI-21 can be
accommodated in 3 tiers, the double channel equipment ETI-22 in 4 tiers and the double
channel, 40W equipment ETI-22(s) in 6 tiers. Furthermore, a mechanical coding system
ensures all plug in units can only be inserted in their correct position.
The ABB free standing cabinet type E-35 can for example, accommodate two single channel
PLC equipment with the associated protection signaling units and an electronic trunk-dialing
unit for 8 telephone subscribers.
A nameplate on the front door of the carrier cabinet carriers relevant information of the PLC
link, such as equipment type, station names, carrier frequency etc.
To enable printed circuit boards to be exchanged without any readjustment being required,
there is on the rear side a strapping field for the initial programming of the system variant and
also for the adjustment of the PLC equalizer.[6]
DESCRIPTION OF PANEL CARDS [6]
PLCC section contains different card which enable it to do its work properly. This card is
specified by the some number and contains inbuilt circuit that performs accordingly.
Different card have different specification these specification can be summed in following
way:-
E3EC Receiver RF Filter
N3FL Test matter
P3EO RF hybrid
E5EA Transmit filter
B5EC Power supply

xxix
B3EA 40 VOLT REGULATOR
B3EB 24 VOLT REGULATOR
P5EA POWER AMPLIFIER
O3EI SUPERVISION
P3EC RECEIVE IF DEMODULATOR
E3ED RECEIVE IF FILTER
P3ED RF & AGC AMPIFIER
P3EF RECEIVE IF MODULATOR
O3EH SIGNAL OUTPUT PIOLT
O3EE TELEPHONE ADAPTOR
O3EG VOICE AMPIFIER
E3EF VOCE FILTER
O3EA TELE OPERATIONAL INPUT
O3ED EXPANDER OR COMPANDER
O3EC SIGNAL ADAPTOR
O3ED DIAL MODULE PIOLT TONE
P3EA TRANSMIT IF MODULATOR
E3EA TRASMIT IF FILTER
P3EB TRANSMIT RADIO FREQUENCY
MODULATOR
E3EB TRANSMIT PER FILTER

xxx
CHAPTER 9
SPECIFICATION OF PLCC
9.1.General:-
1. Carrier frequency range : - 40to512KHZ
2. Gross channel band witch :- 4 kHz
3. Useful AF band : - 300to3700KHZ
Permissible room temperature in climates
1. Data guaranteed within reliable :-0 to 45 degree
centigrade
2. Operation guarantee :-20 to 45 degree
centigrade
3. Frequency stability of RF.F oscillator :-5HZ
9.2.TRANSMITTER
1. R.F. transmitting power
2. Peak envelope power :-25W
3. Side band power :-15W
4. Auxiliary carrier frequency :-16 KHz
At frequency 250 KHZ their power lower by 2 db
1. I.F. carrier frequency :-16 KHz
2. Pilot tone :-3600 Hz
3. Test tone :-1000 Hz
4. Synthesizer reference frequency :-8 KHz
5. Dummy load :-20 OHMS
9.3.TRUNK DIALING

xxxi
Shifting the pilot oscillator frequency of 3600+/-30 transmits dialing criterions’ of a
speed of normally 1- pulses per second.
9.4.POWER SUPPLY
1. DC supply :-49 to 60(-10/+25%),180W
Approximate maximum supply 2 percent
2. Capacity :-800AH
3. A.C. supply :-220+/-15%,50HZ
4. Power consumption :- <80W
In normal rooms the ETI equipment generally erected on an open rack or on a frame of
freestanding cabinet.
The room for the erection of the equipment should have a dust free floor , which is washable.
The room should be well ventilated and of normal temperature and humidity and where
necessary provided with a ventilator fan having a dust filters.
The cabinets should be checked for damage before mounting.
Cabinets should prevent from tilting when opened.
9.5.Caution:-
Before opening the hinged frame, make sure that the cabinet can not tip forward.[6]

xxxii
CHAPTER 10
GENERAL DESCRIPTION OF PLCC EQUIPMENTS
The multipurpose equipment type ETI-21 and ETI-22 transmit simultaneously speech and
multiplexed tele-operation signals in SSB technique over high voltage lines of cables.
The transmitted intelligence is suitable for:
10.1.Telephony tele-operations:-
1. Telemetry
2. Remote control
3. Remote analogue metering
4. Tele-printer
10.2.Tele –protection signals for: -
1. high voltage power equipment
2. High voltage power lines
While the telephone and tele operations facilities are typically used for economic control and
supervision of energy network. The tele-protection channels are kept continuously on hot
standby and are used only in rare cases of a power fault for the planning of new networks and
the extension of existing equipment, the ETI series offers a complete range of variation made
possible by a combination of tiers and plug-in PCB.
The equipment is made of 3 main parts:
1. The low frequency multiplex section:-with the speech and up to 5 tele-
operations channels, together with an optional speech compander.
2. The carrier frequency section:-designed for single channels duplex or
double channel duplex working in a 4 KHz raster. The carrier frequency range
from 24 KHz to 500 KHz and with transmitted power of 20 Watts or a variant
100 Watts.
3. Power supply unit:- which can be operated from 110/220V, 50/60Hz or a
separate battery or charger unit of 24V, 48V or 60V.
The techniques of simple side band modulation with double conversion provides frequency
equalization, automatic gain control and frequency synchronization and ensures perfect

xxxiii
reproduction of the transmitted intelligence, proper distribution of the transmitting power in
normal operation and for the boosting of protection trip signals enables optimum distance to
be converted. The front panel arrangement of operational and servicing elements such as
switches, potentiometer, lambs etc. allows the non- specialist to carry out maintenance of the
equipment with the aid of a built-in test oscillator and handy audio test instrument, a quick
test and level adjustment can be carried out so that with the local transmitter and receiver
connected back-to-back a complete stimulation of the PLC link is established.

xxxiv
CHAPTER 11
APPLICATION OF ETI EQUIPMENTS
The Power Line Carrier (PLC) equipments and the associated protection signaling units are
required to be situated in the area of the high voltage apparatus, thereby facilitating
connections to the PLC’s line coupling equipment. In contrast, the telephone exchange and
Tele control equipments are usually more conveniently situated in a control building some
distance from the high voltage equipment.
According to the type of installation various arrangements are possible. These are as follows:-
11.1.PLC equipment and AF Multiplexer as a combined unit:-
The majority of electricity authorities adopt this arrangement since the complete PLC is
contained in a single cabinet or rack and is easily placed in a suitable telecommunication
room. From this room the individual connections are taken directly to the associated HV
protection circuits and via an appropriate frame, connections to the telephone and Tele control
equipments.
11.2.Remote at multiplexer connected by a long cable:-
The case is that the high voltage lines are terminated in the sub-stations as the edge of the city
while the associated control building or load-dispatching office is situated some Km. away in
the centre of the city. A long 4-wire interconnection cable (Zo = 600chms) connects the
parent PLC equipments with the remote multiplexer.
11.3.Brief characteristics:-
Cable Attenuation - permitted 32 dB maximum
Planning value 26 dB
Frequency band - 300 to 3700 HZ
300 to 3400 HZ Optimal
Adjustable attenuation equalizes for loaded lines, located at both ends.
The facilities available are:-
1. 4 wire duplex speech, from remote location.
2. Duplex tele-operational channels, from remote location.
3. Duplex pilot/signaling channel, from remote location.

xxxv
4. Possibilities for input and output connections of tele-operation signals from
PLC equipment.
5. Optional: service telephone from parent PLC equipment to opposite PLC
station.
11.4Remote at Multiplexer connected by a short line:-
When the distance between the PLC and remote multiplexer is relatively short, i.e. up to
about 3 KMs, And is connected by a 4-wire pilot cable (Zo=600 ohm). Due to the lower cable
attenuation the line amplifier with line equalizer is unnecessary and the cable will be
terminated on the tele-operation input/output circuit (03EA and 03EH/S respectively).
11.5.Protection signaling over PLC equipments where AF Multiplexer is
Remote:-
Tele-protection equipment can be coupled directly to the PLC equipment. This means the
PLC has to function fully independently of the transmit signals from the remote multiplexer.
This will be the case when a pilot signal P-1 is used from AF Multiplexer to PLC equipment.
A further pilot tone P-2 of the same frequency is transmitted from the PLC equipment to the
opposite PLC station. The signaling impulses carried by the pilot tones are looped from p-1 to
P-2 in DC form at the PLC equipment. The pilot tone P-3 from the opposite station is
received directly at the remote multiplexer.
11.6.Repeaters:-
When several transmission sections are joined together to form a long transmission path, the
ETI equipment can serve as repeaters at the intermediate station. In each transmission section
the carrier signal will be individually regulated, synchronized and equalized and the
transmitted intelligence at each repeater station will be demodulated and passed on to the next
station.

xxxvi
CHAPTER 12
MODE OF OPERATION
The PLC equipment is suitable for connecting to a telephone exchange and further more, a 4
wire remote/emergency call station can be created by operating it in parallel with the built in
service telephone equipment. The transmission facilities for tele operation working
(telemetry, tele-control and protection signals) use separate input and separate output circuits
according to their classifications.
When 4-Khz equipment carries simultaneously the speech and Tele operation signals , they
are transmitted in frequency multiplex and accordingly the audio frequency band is divided
into two parts. The lower part is used for speech and the upper part for tele operation signals.
12.1.1.Telephone facilities:-
The associated automatic telephone exchange (PAX) is suitable for a network with a limited
number of subscribers. Between the PAX and PLC channels, controls circuits give out-signals
for the setting up, dialing and later releasing a telephone connection and the switching criteria
between PAX and PLC equipment is performed by potential free contacts. The PAX sending
contact will, via the PLC signaling channel close an output contact in the PLC receiver and
the distant end of the link.
12.1.2.Compressor and Expander:-
The inclusion of a Compander improves the carrier signal quality of the speech and in
normally reserved for use over lines with high noise. The improvement in the signals to noise
ratios is approximately 12 dB. When the speech is carried over several PLC links in series, it
is recommended that only one Compander be used, the compressor being installed at the
sending end of the line and the expander in the farthest receiving station. The ETI series is
fully wired for a later inclusion of the compander equipment when required.
12.1.3.For wire hand/emergency call:-
The equipment, especially in the extension phases can, without additional units in the HF
equipment is equipped throughout with hand/emergency call telephone. This telephone with
DC dell can be connected directly via a 6-wire extension cable. The calling of the opposite
station is accomplished lifting the handset and pressing the calling button in the opposite
station after a 2 second delay the bell rings as long as the push button is pressed. By lifting

xxxvii
the handset the called station, the bell is automatically disconnected. After the call is
completed both handsets must be replaced. The calling tone is fixed at 1 KHz in the speech
band.
12.1.4.Service telephone:-
With the help of the built in speech facilities, service calls can be carried out in 4 wire from
the front panel associated equipment, including the DC belt and the plug in 4 wire handset are
supplied.
12.1.5.Tele-operation signals:-
Individual and adjustable Tele operation inputs are the essential requirements of the PLC
equipments for the interfacing with the various manufacturers’ low frequency transmission
channels and for PLC through switching/transit working. The 5 input and 3 output
possibilities, each individually adjustable and fully de-coupled together with the separated
terminals. For protection signaling equipment, offer the necessary flexibility. A strapping field
is provided for choosing the various modes of operation.
12.1.6.Signal boosting:-
The equipment offers the possibility of signal boosting of one or two especially important
signals, for example protection signals for high voltage lines or equipment. This is
advantageous during unfavorable transmission condition caused by perhaps fault conditions
on the power line. During boosting , the less importing channels, for example, the speech are
disconnected (known as disconnected channels) whereas other channels can be allowed to
work normally (non-disconnect -able channels).
The arrangement of speech and Tele operation channels fall into one of three categories and is
achieved by connecting to one of the following input:-
1. The disconnect able bus (D)
2. The non-disconnect able bus (ND)
3. Signal boosting bus (B) with a predetermined amplification.
12.2.Fault analysis, test equipment and test procedure:-
12.2.1Test equipments:-

xxxviii
Test oscillator enables the commissioning of the PLC link without aid of external signals,
pressing the CALL button initiate a test tone of 1KHz which is fed to the voice amplifier and
passes through all transmit stages of the PLC equipment with the exception of the telephone
adaptor. It is possible to check at any test point the dB value printed in the front side of the
equipment is against the measured dB reading. The following signals can be checked in the
AF section of the equipment:-speech, tele operation/data dialing.
12.2.2Fault analysis:-
In fault analysis the faulty devices are checked in this serial or manner:
1. Telephone or Tele operation signals
2. Cabling low frequency circuits or DC power supplies
3. PLC Equipment
4. HF transmission path
Comparisons with the transmissions levels and working voltages measured under healthy
conditions are valuable aids to fault analysis. The back-to-back testing of the equipment using
the dummy load is also a very useful aid.

xxxix
CHAPTER 13
BATTERY CHARGER
Fig-13.1(Battery charger) Fig-13.2(Block Dia. Of Float Charger and Boost Charger)
PLCC works on rectified AC or main, when make supply goes off. We use of a device for
proper functioning of PLCC, called BATTERY CHARGER. This is the device that provides

xl
supply to the PLCC equipment for uninterrupted working. It provides DC to the panel by
battery of 48V. In this type 24 batteries are connected in series and individually per battery
has approximately 2V capacities.
13.1.General description:-
Battery charger mainly consists of 4 sections:-
1. Float charger
2. Boost charger section
3. Control section
4. Alarm section
All the four sections are situated in mounted sheet steel. The sides and tops of the frame are
provided with removable panels suitable recess has been provided in front panel to prevent
the component from projecting out. All meters indicating lamps, push buttons have been
mounted on front panel.
13.2.Technical specifications:-
1. Normal input :- 415 V AC 3 Phase
2. Input variation :- +/- 20% of voltage
Float charger:-
1. Efficiency :- >70%
2. Line regulation & load regulation :- +/- 1% individual
3. Ripple :- 0.6 V PP (Peak to peak)
Boost charger:-
1. DC output :- 43.2 to 67.2 V
2. Output current: - 25-70 Amps.
3. Over load :- 10%
4. Efficiency :- >80%
13.3.Float charger:-
The float charger is basically static type 3-phase charger with stabilized output DC voltage.
The charger output DC voltage is constantly compared with standard DC reference voltage
and error voltage is again amplified. This amplified voltage controls the triggering signals of
all the 3 thrusters of 3 phase bridge control rectifier, as the output voltage tends to decrease

xli
than it’s selected value, it makes the triggering signals of each thyristor of all 3 phase, to
advance for firing them, so that the output voltage remains within the specified accuracy. If
the output voltage tends to increase more than the selected value, the triggering pulses of
these thyristors of all 3 phase are delayed in firing operations in such a way so that the output
DC voltage is again brought back to its stabilized voltage.
13.3.1.Circuit description:-
The 3-phase AC output is applied through the 3-poles 2 way switch (RS-I) and fuse F-18 to
F-20 to the float input contractor (CON-1). Resistance R-3, capacitor C-2 and also resistance
R-2, capacitor C-1 are incorporated to remove the instabilities like hunting. Operational
amplifier ( IC-2 1 liner amplifier )drop mV across shunt. The ratio of the amplifier and RV-2
on sub assembly sets the charging current increases the mV drop across pin No. 2 & 3 of IC-2
will be increased. This voltage is applied to the base of TR-4 through R-11. Transistor TR-4
will be the base current of TR-3 will increase the voltage from D-2 will control the voltage
correcting operational amplifier IC-1. This will result in decrease in DC output voltage to
keep the battery current at set level, which can be adjusted by potentiometer RV-2.It is
desired that output of the rectifier attain its steady state values slowly rather than by
step.
13.3.2.Fuse fail alarm:-
Fuse fail alarm is also available in float charger. In the event of any HRC fuse failure.
Corresponding types fuse blows and trip the corresponding relay.
13.4.Boost charger section:-
13.4.1.Description of circuit:-
Boost charger is used to charge the batteries after power resumption. The input supply is
switched on mains of rotator switch RS-1, three numbers HRC fuse. F-21 to F-23 has been
provided for over current protection. AC contractor CON-2 has also been provided.
Transformer-6 steps down the input AC voltage to suitable level. Necessary taps are provided
in the primary of transformer to cater for varying input voltage that may prevail at sub-
station. The secondary voltage of transformer-6 is applied to a bridge rectifier, which consists
of 6 silicon diodes D-6 to D-11, for rectification of AC to DC. These diodes are mounted on
individual heat sinks for cooling so that junction temperature of the device is within specified
limit. The diodes are protected by capacitors and resistances against have storage effects and

xlii
transmit over voltage in also by HRC fuses F-10 to F-15.
The battery can be charged by using the two rotator switches provided on front panel for
coarse and fine control and that charging current can be read by ammeter A-3 provided on the
front panel. The operator must ensure that the rotatory switches are in minimum position
before switching on the boost charger.
13.4.2.Operation of charger:-
The float or boost charger can be switches ‘ON’ by means of selector switch RS-1. Thus at a
time only one charger either float or boost can be operated.
When the charger is operated in float mode the battery is on float charge and all the VDD’s
are bypassed through the contacts of DC contractor. This enables complete voltage appearing
on the load. In case of mains fall also the entire battery voltage is available on load through
contacts of DC contractor. When the charger is operated on boost mode, the contacts of DC
contractor are opened. Load voltage can be adjusted by VDD switch RS-8 as per the
requirement main switch RS-9 have been provided to isolate the charger from load and
battery. When the selector switch RS-9 is in charger mode then it will supplying load as well
as trickle charger. The batteries in float and boost charger, the batteries mode when the switch
RS-9 is in mains mode, then the load will be supplied by the battery and the charger is totally
isolated from battery for charger mains purpose.[9]

xliii
CHAPTER 14
APPLICATIONS OF PLCC
PLCC technology can be deployed into different types of applications in order to provide
economic networking solutions. Hence merging with other technologies it proves useful in
different areas. These are few key areas where PLC communications are utilized:
1. Transmission & Distribution Network: PLCC was first adopted in the
electrical transmission and distribution system to transmit information at a fast rate.
2. Home control and Automation: PLCC technology is used in home control
and automation. This technology can reduce the resources as well as efforts for
activities like power management, energy conservation, etc.
3. Entertainment: PLCC is used to distribute the multimedia content throughout
the home.
4. Telecommunication: Data transmission for different types of communications
like telephonic communication, audio, video communication can be made with the
use of PLCC technology.
5. Security Systems: In monitoring houses or businesses through surveillance
cameras, PLCC technology is far useful.
6. Automatic Meter Reading :Automatic Meter reading applications use the
PLCC technology to send the data from home meters to Host Central Station[7]

xliv
CHAPTER 15
ADVANTAGES& DISADVANTAGES OF PLCC
15.1.Advantages:-
1. No separate wires are needed for communication purposes, as the power lines
themselves carry power as well as communication signals. Hence the cost of
constructing separate telephone lines is saved.
2. When compared with the ordinary lines the power lines have appreciably
higher mechanical strength. They would normally remain unaffected under the
conditions, which might seriously damage telephone lines.
3. Power lines usually provide the shortest route between the power stations.
4. Power lines have large cross-sectional areas resulting in very low resistance
per unit length. Consequently the carrier signals suffer much less attenuation
than when they travel on usual telephone lines of equal lengths.
5. Power lines are well insulated to provide only negligible leakage between
conductors and ground even in adverse weather conditions.
6. Largest spacing between conductors reduces capacitance, which results in
smaller attenuation at high frequencies. The large spacing also reduces the
cross talk to a considerable extent.
15.2.Disadvantages:-
1. Proper care has to be taken to guard carrier equipment and persons using them
against high voltages and currents on the lines.
2. Reflections are produced on spur lines connected to high voltage lines. This
increases attenuation and creates other problems.
3. High voltage lines have transformer corrections, attenuation carrier currents.
Sub-station equipments adversely affect the carrier currents.
4. Noise introduced by power lines is far more than in case of telephone lines.
This is due to the noise generated by discharge across insulators, corona and
switching processes.It is obvious that an effective power lines
carrier system must overcome these and many other
difficulties.

xlv
CHAPTER 16
PRECAUTIONS& MAINTENANCE
1. All connections should be thoroughly checked.
2. The control circuit boards should be inserted far firmly in their respective
sockets before energizing the battery charger.
3. All mounting bolts/screws should be checked before energizing as loose
mounting will cause vibrations.
4. The charger should be switched off once in every month and the connections
and mounting should be checked.
5. The battery terminals should be connected first and the AC input after that.

xlvi
CHAPTER 17
CONCLUSION
Companies used Power Line Communication to maintain power grid due to past low data rate
communication needs. High data-rate communication over low-tension lines is one of the
major applications in new technologies. Power Line Carrier Communication offers symmetric
as well as two way communication along with a permanent connection. Load management
and meter reading from a distance are the two Primary motivations for Power line
communications in future. In Automatic Meter Reading electronic data that is the meter
reading is transmitted over power lines from a distant place back to the substation where the
reading has to be noted, then the reading is relayed to a central computer in the utility's main
office. Hence this would be considered a type of fixed network system.
In today world power-line-communication is being used for many applications to control
various systems such as street lighting or energy management systems. In homes the so called
"baby-phones" are very popular in which power line communication is used in which low
quality analogue voice signals is transmitted through a 230V mains wiring. In comparison to
the old analogue systems used for communications, digital data which is transferred using the
power-line as communication media is a very useful alternative for domestic applications,
particularly for devices which are already connected to the mains (e.g. washing machines or
refrigerators, linked together for energy management). Power line communication saves the
biggest part of installation costs if it is used in buildings where electric wiring is already
present hence no need for wiring separately for communication. Hence power line
communication meets the customers’ needs for low cost.
Indoor power line communication should not be mixed with outdoor power Line
communications as both are different from one another regarding the availability. The indoor
power line communication is capable to transmit information at a rate of 2400bps (bits per
second) at a very low cost. For domestic applications this rate of data transmission is good
enough as in most of the cases in domestic applications the devices have to transmit only
control signals such as on/off, dimming values etc.

xlvii
REFRENCES
[1] http://www.rajasthandirect.com/government-department/rajasthan-state-electricity-board
[2] http://electrical-engineering-portal.com/power-line-career-communication-plcc
[3] http://www.engineersgarage.com/articles/plcc-power-line-carrier-communication
[4] en.m.wikipedia.org/wiki/Power-line_communication
[5] en.m.wikipedia.org/wiki/Amplitude_modulation
[6] Manual of ETI equipment
A.B.B(Asea Brown Bowery Ltd)
[7] ] http://www.engineersgarage.com/articles/plcc-power-line-carrier-communication
[8] [ N.N.Biswas and Edition-1975], “Principles of carrier communication”.
Page no.101-103
[9].Manual on Battery Charger
Omega Electroics
[10] slideshare.net/mobile/vishu_angira/power-line-career-communication

PLCC Summer Training Report Summary

Recomendados

Recomendados

Más contenido relacionado

La actualidad más candente

La actualidad más candente (20)

Destacado

Destacado (12)

Similar a PLCC Summer Training Report Summary

Similar a PLCC Summer Training Report Summary (20)

Último

Último (20)

PLCC Summer Training Report Summary