INDUCTION LEVEL TRAINING AT RTC MSETCL AURANGABAD
Power Line Carrier
Communication (PLCC)
Work book 1
(For Private Circulation only)
Guided by
Shashank S. Jewalikar
SE TCC MSETCL Aurangabad
Dedicated to
My mother who taught me to do my
best at all times
Compiled by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Mobile no. 9405600828 (P) / 9767104420 (O)
E mail ID - kulkarni.sunildatta@gmail.com, dyeetelecom@gmail.com
First Edition (dt. 4/12/2012)
Notes
Page 1 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Power Line Carrier Communication
Complete the sentences with the words from the box given below
The power line carrier communication is a technology which uses
__________________________ as physical media for ______________, __________&
______________________________________ transmission.
Fig Power line carrier communication
As shown in fig the __________________________________________ are used for
communication instead of separate telephone lines.
Power lines are extremely robust & connect the nodal points between which
communication is normally required.
Who helps you to keep Electrical power flowing?
____________________________ Networks help power utilities keep _______________
flowing all the way from generator to consumer.
Power utility operators communicate with each other to
____________________________ & exchange all kinds of ________________________
information.
Speech, data, protection signal, power line, communication, power line
conductors, operational, co ordinate actions, electricity
Page 2 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Exercise
Look at the pictures & write their names in the blanks provided below the pictures.
1.__________________________
2_________________________
4 ________________
3_______________________
5 ____________________
6_______________
Page 3 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
________ TRAP
Complete the sentences with the words from the box given below
Wave traps are _______________ connected to the transmission lines.
The Wave trap is ___________ tuned circuit that presents _________ impedance to
carrier frequencies (50 KHz to 500 KHz) and ___________ impedance to the power
frequency (50 Hz).
Main components
1. L (Main Coil) – The coil is rated to carry _______ line power frequency
current.
2. Tuning Pot is used to ___________ the carrier frequency entering the substation.
3. LA (Protective device) protects against high voltage __________ caused by
_____________________ or _______________________________.
In Wave trap Main Coil, LA & Tuning device are _________ connected to
each other.
The __________________ of a trap is judged by its _________________ loss &
Blocking ______________________________.
For an ideal wave trap the insertion loss would be _____________ & blocking
attenuation __________________.
For a well designed wave trap insertion loss is 1 to 3 dB & Blocking Attenuation is 8
to 10 dB.
Insertion, Attenuation, Series, Parallel, Wave, Low, Shunt, High, Full, surges, Efficiency, Block,
infinite, switching operations, zero, Atmospheric effects
Page 4 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Exercise
1. Label the parts of Line trap (Wave trap) given below.
Page 5 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Exercise
Select Blocking band for Power line carrier terminal having frequency 176/172 U KHz.
Fig Tuning pot
1. Band I (90 – 150 ) KHz - Connect the Line trap across A & B and Short B & B1.
2. Band II ( 150 – 500 ) KHz – Connect the line trap across C & D and Short D & D1.
Answer –
Page 6 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Coupling ___________________________
Complete the sentences with the words from the box given below
The main _____________ of coupling Capacitor is twofold.
1. _______________ Of PLCC terminals from ___________________ voltage.
2. ________________ the HF signal with __________________ attenuation.
It is permanently energized by the ____________ voltage of the power line and
should be able to withstand, without damage, the over voltages due to steep fronted waves,
which may on occasions reach several times the rated voltages.
One end of the Coupling Capacitor must be securely connected to ____________.
Otherwise _______________ voltages up to the magnitude of the operating voltage may
occur on the equipment side of the capacitor.
Protection ,Purpose, Extra High , Minimum, Coupling, Passing, Over, Ground, Normal,
capacitor
Exercise
2. Label the parts of Coupling Capacitor given below.
Page 7 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Capacitive ______________ Transformer
Complete the sentences with the words from the box given below
CVT consists of Coupling __________________________________ &
________________________________________________Transformer.
_________________________________ Transformer for
____________________________or control
& Coupling Capacitor for ___________________________________
communication.
Voltage, Capacitor, Potential, Monitoring, Carrier
Page 8 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Line _________________ unit (LMU) or coupling device (CD)
LMU is mounted on the structure that supports the coupling capacitor.
Exercise
1. Label the parts of Line Matching Unit (LMU) given below.
Page 9 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Complete the sentences with the words from the box given below
1. BT ______________________________ provides better
_______________________ & couples the output of the PLC terminal to the
coupling filter.
It ensures the carrier signals are in healthy condition even under the failure of
any of the coupled phases & thus provides greater channel dependability.
2. MT ______________________________________________________ performs the
function of ________________________ matching and high voltage
______________ between carrier equipment & line side.
3. The coupling filter together with the external coupling capacitor forms a T section
__________________________________________________.
Matching Transformer, Balancing Transformer, Phase
splitting, Impedance, Band Pass filter, Isolation
Exercise
2. Select the Pass band of LMU for Power Line Carrier Terminal having frequency
( 176/172 ) U KHz
Pass band
1. 35 - 50 KHz
2. 50 – 90 KHz
3. 90 – 500 KHz
Page 10 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Three elements _____________________ device
Complete the sentences with the words from the box given below
Three element protection device
The three element Protection device consists of ____________________ coil, LA &
____________________________ switch.
1. ________________________________ for draining of ________________
frequency currents to earth.
2. LA for ____________________ protection at the primary terminals of coupling
device.
3. Earthing switch for _______________ and _________________ earthing of primary
Terminals.
Direct, Protection, Efficient, Drain, Earth, Drain coil,
Power, Transients
Page 11 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Insulated Single Conductor Lead in wire
Complete the sentences with the words from the box given below
To connect the coupling capacitor to the ____________________________, use an
____________________________________________________________________.
Bare __________________ & ____________________________ cable should not
be used for this because it is possible to introduce excessive
___________________________ with former case & excessive
________________________________ with the latter.
The connection between the CC & LMU is a _____________________ impedance
point in the ___________________________ tuned circuit formed by the tuning
inductor & coupling capacitor.
Stray capacitance & leakage to ground will increase the ___________________ of
LMU and affect the _________________________.
Bandwidth, Losses, Series, High, Coaxial, Conductors, leakage to Ground, Capacitance, Insulated single
conductor lead in wire , Line matching Unit
Page 12 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
HF Cable or Coaxial cable
Complete the sentences with the words from the box given below
Coaxial cable is a __________ conductor cable made of a single conductor
surrounded by a ________________________, with a plastic insulating material separating
the two.
. The coaxial cable provides ____________________________ so that noise cannot
get into the cable and cause ________________________________.
The characteristic impedance of the coaxial cable is either _____ or _________
Ohms.
Characteristic Impedance( Z0 ) of a transmission line is defined as the ratio of the
voltage to the current of a traveling wave on a line of __________________ length.
Characteristic impedance of line, Z 0 = 276 log D/r
Where D-Distance between Conductors, r- Radius of Conductor
Characteristic Impedance is also known as _______________________ Impedance, due to
the temporarily ______________________________________________ behavior of any
length transmission line .
75, Resistive, Shielding, Surge, Infinite, 125 , Braided wire jacket, two, interference,
Page 13 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Power line Carrier Terminal (PLCT)
Complete the sentences with the words from the box given below
Fig Power line Carrier Terminal
Power line carrier Terminal ________________ a input signal of 4 KHz
bandwidth to the Radio Frequency RF signal and ____________________ this signal to the
desired output power level up to ________ watts.
The RF range in PLCC system is _______KHz to __________KHz.
PLCC works on Modulation and Demodulation Process.
• _____________________ is a technique used to convert a ________ frequency
signal (information signal) to a higher frequency signal (modulated signal) using a
______________ frequency signal (carrier).
• __________________ is the opposite technique where information signal is extracted
from the carrier.
• Modulation & Demodulation requires ____________ frequency which is generated
in PLCC Panel.
Carrier, Amplitude, Demodulation, Modulation, Low, higher, 500 , 50 , converts, amplifies, 40
Page 14 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Power Line Carrier Link (PLC link)
Complete the sentences with the words from the box given below
(Make, Type, SC/TC & Tx Rx Fr.)
(Make, Type,SC/TC & Tx Rx Fr.)
PLCC Terminals /Panels /sets/Cabinets are used as a ___________, one at each end
of the power line (between substations)
Each PLCC Terminal is designated for a set of _______________ and
_____________ frequencies (Channel Frequencies).
These frequencies may be ______________ or _________________.
The corresponding PLCC terminal at the other end will be designated for the
_______________ value of the transmission and reception frequencies.
The channel Frequency will be either in __ KHz or ____ KHz bandwidth depending
upon _________ channel or _______ channel.
8,4, Single, Twin, reverse, Separate, pair, adjacent, Receive, transmit,
Page 15 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Exercise
Fill in the blanks
1. PLCC freq band from ______to ___________KHz
2. Pilot Frequency
________________Hz
3. Telephone frequency from _____to ________Hz
4. Dial Frequency __________________Hz
5. Guard Frequency _________________Hz
6. Protection (Trip) Frequency ________Hz
7. Data Frequency band _____________ KHz
Page 16 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
PLCC Coupling Schemes
Economic, Engineering & common sense
Mode 1 coupling
Center ph to Outer ph (No Mode 3)
Center ph to Ground ( No mode 2)
Outer ph to outer ph with Ground return (No mode 2)
Outer ph to Ground ( All 3 modes)
Modal Analysis
Complete the sentences with the words from the box given below
Modal analysis is a ________________ tool similar to symmetrical
components used for analyzing __________________ faults on three phase power systems.
It can be shown that the number of natural _________ is equal to the number
of ____________ involved in the propagation,
For example, _____ nodes in the case of a ____________ circuit line with
__________ earth wires earthed at each tower
The phase conductor currents or voltages can be ___________ into ________
sets of natural mode components at any point on a lossy, reflection free three phase line.
Each mode has its own characteristics.
Resolved, three, mathematical, unbalanced, nodes, conductors, single, three,
Page 17 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Mode 1 is the _______ attenuated and least ____________ dependent
Mode 2 is __________ frequency dependent and has more ___________ than mode 1.
Mode 3 is the ___________ attenuated mode and is propagated on all _____ phases and
___________ via the ground.
1. Centre Phase to Ground Coupling
2. Outer Phase to Ground Coupling
3. Center to Outer Push Pull coupling
4. Outer to Outer Push Push coupling
Least, Frequency, attenuation, more, highest, three, returns
Page 18 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
PLCC Network
Complete the sentences with the words from the box given below
Telephone –
1.
A user end instrument that is used to transmit &
receive ______________ frequency signals.
2.
Voice frequency is audio range used for transmission of
__________ ( _______ to _________________ Hz)
3.
Telephone bandwidth for a ________ voice frequency
channel is ______________KHz.
Single, 4, Voice, Speech, 3400 , 300,
Page 19 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Main Parts of Telephone
Transmitter (________________________)
Receiver (_____________________________)
Hook switch
Keypad
Tone Dialing
PLCC Numbering Scheme
PLCC Numbering scheme is ___________ numbering scheme.
Whenever subscriber dials a number he knows whether he is dialing for the local
exchange or remote PLCC exchange.
The dialing is ___________________ to the subscriber.
Network Access code + Reachable ID + Subscriber no.
0
+ 32
+ 41
Transparent, Open, Speaker, Microphone
Page 20 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Complete the sentences with the words from the box given below
Conventional __________ distance Protection System
Fig Conventional Protection System
Fig Trip Logic
In the absence of communication link, the operation of End zone fault is
_______________ & ___________________________________________ is not possible.
Zone 1 time
Zone 2 time
Zone 3 time
400 KV
0 ms
300 ms
500 ms
220 KV
0 ms
400 ms
700 ms
Auto reclosing, longer, 3 Zone
Page 21 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Complete the sentences with the words from the box given below
Carrier _________________ Protection
Carrier aided protection scheme is used for ________________ tripping of near &
far end ______________________.
Protection Coupler equipments can be used along with PLCC terminals for
Tele protection requirements.
Fig Carrier aided protection
Fig Trip Logic for Carrier aided Protection
Circuit Breakers, Simultaneous, Aided
Page 22 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Complete the sentences with the words from the box given below
Principle of operation
Under ________________ conditions, i.e. when there is __________________ in the
line, _______________ frequency or frequencies G1 & G2 will be continuously
transmitted through the PLC channel for monitoring the __________________ of the
equipment.
In the event of operation of protection due to ___________, the guard signals will be
cut & corresponding ___________________signals will be transmitted in the
_______________band.
____________ & any other _______________ transmission are interupted while the
trip signals are being transmitted.
Exercise
Show Protection Signal Path from sub A to B in Figure below –
Trip, Normal, Guard, healthiness, no fault, Speech, Data, fault,
Page 23 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Data / Telemetering
PLCC terminals can be used for sending / receiving data signals for
Telemetering, etc.
The input signal for this channel will be between 2000 to 4000 HZ.
VFT – MODEM will be connected with PLCC for this purpose along with RTU.
The NSK 5 is a new, fully programmable frequency shift keying (FSK) modem
for data transmission over PLC links.
Speed of the data transmission starts from 50 Baud (Available 50.100, 200,
.300, 600, 1200 & 2400 Baud)
Generally 300 or 600 Baud rate is used over PLCC.
In case of more Baud rate is required Full AF Band of PLCC to be used.
Output & Input of NSK 5 to be interfaced with data Input & Output section of
PLCC.
Page 24 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune
Programming with NSK 5
Switch S1 – 1,2,3 for baud rate setting & 4 to 8 for Transmit frequency setting
Switch S2 - 1,2,3 for Rx sensitivity setting & 4 to8 for Receive frequency setting
CA.CB,CC,CD,CE,CF – Transmit level setting
AH/AF, AB/AA – Jumper setting for Transmitter & Receiver termination impedance
Page 25 of 26
PLCC Workbook 1 by Sunildatta V Kulkarni DyEE PLCC MSETCL Pune