Relay Protection

1. SEMINAR REPORT ON:
SWITCHYARD EQUIPMENTS & PROTECTION SYSTEMS.
At
Submitted By:
PARTHA SARATHI PARIDA
REG NO. 10010133
7TH SEMESTER
ELECTRICAL ENGINEERING
NTPC-SAIL Power Company Private Limited, Rourkela.
VEER SURENDRA SAI UNIVERSITY OF TECHNOLOGY, BURLA, ODISHA.
DEPARTMENT OF ELECTRICAL ENGINEERING

2. NSPCL, ROURKELA CAPTIVE POWER PLANT
NTPC Ltd formed joint venture with SAIL on 50:50 basis in March 2001 in the name
of NTPC-SAIL Power Company Private Limited (NSPCL). NSPCL took over captive
power plant-II located at Rourkela Steel Plant (2X60 MW) from SAIL.
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013

3. AN OVERVIEW OF CPP :-
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013

4. MAJOR EQUIPMENT IN CPP :-
• 2 GENERATORS
• 2 GENERATOR TRANSFORMERS
• 2 UNIT AUXILIARY TRANSFORMERS
• STATION TRANSFORMERS
• FEEDERS
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013

5. TECHNICAL DATA OF GENERATOR UNIT 1 AND 2:
• Generator Type : THRI 86/35
• Year of manufacture : 1985
• Stator No. : 1134 & 1135
• Rotor No. : 1134 & 1135
• Exciter type : Static
• Apparent power : 75 MVA
• Active power : 60 MW
• Current : 3.766 KA
• Voltage : 11.5 KV +5%
• Speed : 3000 Rpm
• Frequency : 50 Hz
• Power Factor : 0.8
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013

6. TECHNICAL DATA OF GEN. TRANSFORMER UNIT
1 AND 2:
• Make : Crompton Greaves Ltd
• Rating : 16.5/33/82.5/ MVA
• Type of cooling : ONAN/ONAF/OFAF
• No load voltage : HV : 138KV , LV : 11.5KV
• Winding : HV : STAR , LV : DELTA
• Phases : 3/3
• Frequency : 50 Hz
• Vector group : Ynd 11
• Rated current : HV : 345.20Amps ,LV 4141.90
Amps
• Total oil qty : 24,470 Lts
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013

7. TECHNICAL DATA OF UNIT AUX. TRANSFORMER
UNIT 1 AND 2:
• Make : Crompton Greaves Ltd
• Rating : 12.5 MVA
• Type of cooling : ONAN
• Voltage : HV : 11.5 KV , LV : 6.9 KV
• Phases : 3/3
• Frequency : 50 Hz
• Vector group : DYN 1
• Rated current : HV : 627.5 Amps ,
LV:1045.9 Amps
• Total oil qty. : 9,000 Lts
• Percentage impedance voltage : 7%
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013

8. TECHNICAL DATA OF STATION AUXILIARY
TRANSFORMER:
• Make : Crompton Graeves Ltd
• Rating : 20/25 MVA
• Cooling : ONAN/ONAF
• No Load voltage : 132/6.9/3.3 KV (UNLOADED )
• Current: HV 109.3 Amps LV 2091.8 Amps
• Frequency : 50 Hz
• Vector Group : YNY nd 011
• quantity of oil : 17500Lts
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013

9. SWITCHYARD:
SALIENT FEATURES OF 132KV SWITCHTYARD:-
• 20 OPERATING BAYS
• 02 GENERATORS
• 04 GRIDCO FEEDERS
• 06 SMELTER FEEDERS
• BUS COUPLER
• BUS TIE CUM BUS COUPLER
• STATION TRANSFORMERS
• 01 BT BAY
• ISOLATION TRANSFORMERS
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013

10. IMPORTANT COMPONENTS OF THE SWITCH YARD:
1. BUSBARS:
TYPES OF BUSBAR ARRANGEMENTS:
1. Single Bus-bar Arrangement.
2. Single Bus-bar System with Sectionalization
3. Ring Bus-bar system
4. Double Main and Transfer Bus-bar Arrangement
5. Duplicate Bus-bars System
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013

11. 1. SINGLE BUS-BAR ARRANGEMENT
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013
In this arrangement a set of bus-bars is used for complete power station and
to this bus-bar are connected all generators, transformers and feeders
through circuit breakers and isolating switches.

12. 2. SINGLE BUS-BAR SYSTEM WITH SECTIONALIZATION
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013
With increased number of generators and outgoing feeders connected to
the bus-bars, it becomes essential to provide arrangement for
sectionalizing the bus-bars so that a fault on any one section of the bus-
bars may not cause a complete shutdown. This is achieved by providing
a circuit breaker and isolating switches between the section.

13. 3. RING BUS-BAR SYSTEM
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013
In this arrangement each feeder is supplied from two paths, so that in
case of failure of a section, supply is not interrupted.

14. 4. DOUBLE MAIN AND TRANSFER BUS-BAR
ARRANGEMENT
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013
This arrangement incorporates all advantages of the double bus as well as
transfer bus scheme. This scheme needs a bus-coupler for the on load transfer of
circuits from one main bus to the other and a transfer coupler for taking out
circuit breaker of various circuits for maintenance.

15. DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013
2. BUS COUPLER:
• Two different bus sections of two different power transformers are
connected by means of a bus coupler.
• The bus coupler becomes useful when one of the power transformers
fails or a fault occurs in either of the bus sections.
3. INSULATORS:
• The overhead line conductors should be supported on the poles or
towers in such a way that currents from conductors do not flow to
earth through supports i.e., line conductors must be properly insulated
from supports. This is achieved by securing line conductors to supports
with the help of INSULATORS.
• The insulators provide necessary insulation between line conductors
and supports and thus prevent any leakage current from conductors to
earth.

16. TYPES OF INSULATORS:
1.PIN TYPE: 2. SUSPENSION
TYPE:
3. STRAIN
INSULATORS:
4. SHACKEL
INSULATORS:
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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03-Nov-2013

17. 4. CIRCUIT BREAKER & RELAYS:
• A circuit breaker is an automatically operated electrical switch designed
to protect an electrical current from damage caused by overload or
short circuit.
• Its basic function is to detect a fault condition and, by interrupting
continuity, to immediately discontinue electrical flow.
• The circuit breaker works along with the relays which give a tripping
signal in case of any irregularity or the faults.
• The circuit breaker then opens to open the circuit such that other
instruments of the system can be protected.
03-Nov-2013
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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18. 5. ISOLATORS: (GOD)- GROUP OPERATED DISCONNECTOR:
• It is used to make sure that an electrical circuit can be completely de-
energised for service or maintenance.
• It allows isolation of apparatus such as circuit breakers and
transformers, and transmission lines, for maintenance.
• GOD’s are provided to facilitate isolation of breakers supplying power to
various feeders. In 220kv Switchyard, they are designed as 29A, 29B,
29C & 29E as follows
 29 A – main bus side GOD.
 29 B - Equipment side GOD.
 29 C - Transfer bus side GOD.
 29 E - Earth GOD.
03-Nov-2013
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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19. 6. Current and voltage transformers
• Current or voltage instrument transformers are necessary for isolating
the protection, control and measurement equipment from the high
voltages of a power system, and for supplying the equipment with the
appropriate values of current and voltage - generally these are 1A or 5Α
for the current coils, and 120 V for the voltage coils.
03-Nov-2013
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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CURRENT TRANSFORMER VOLTAGE TRANSFORMER

20. 8. LIGHTNING ARRESTER:
• A lightning arrester is a device used on electrical power systems
and telecommunication systems to protect the insulation and
conductors of the system from the damaging effects 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.
03-Nov-2013
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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LIGHTNING ARRESTER

21. TRANSFORMER YARD:
• Transformer yard consists of following types of transformers
03-Nov-2013
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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22. CONCLUSION :-
• Switchyard is most essential part of the power system.
• It is the protective part of the whole power system.
• Switch yard is also most essential part for transmission, distribution, and
collection.
03-Nov-2013
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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BIBILIOGRAPHY :-
1. http://wikipedia.com
2. http://google.co.in
3. http://www.engineersedge.com
4. http://www.scribd.com
5. http://electricals4u.com
6. Power system Engineering by O P KOTHARI and I J NAGRATH
7. Power System By J B GUPTA

23. 03-Nov-2013
DEPARTMENT OF ELECTRICAL ENGINEERING,
V.S.S.U.T,BURLA
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