AIS & GIS Page 1 Air Insulated and Gas Insulated Substation A Seminar Report Submitted in Partial Fulfillment of the Requirements for the Degree Of Bachelor of Technology In Electrical Engineering Submitted By: Pathik Patel (13BEE079) Rajkumar Patel (13BEE081) Under Guidance of: Prof. C.R.Mehta Department of Electrical Engineering Institute of Technology, Nirma University Ahmedabad – 382481 April 2015
22
Embed
Seminar Report on Air Insulated and Gas Insulated Substation
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
AIS & GIS Page 1
Air Insulated and Gas Insulated Substation
A
Seminar Report
Submitted in Partial Fulfillment of the Requirements for the Degree
Of
Bachelor of Technology
In
Electrical Engineering
Submitted By:
Pathik Patel (13BEE079)
Rajkumar Patel (13BEE081)
Under Guidance of:
Prof. C.R.Mehta
Department of Electrical Engineering
Institute of Technology, Nirma University
Ahmedabad – 382481
April 2015
AIS & GIS Page 2
ACKNOWLEDGEMENT
It is our proud privilege and duty to acknowledge the kind of help and guidance received from
several people in preparation of this report. It would not have been possible to prepare this report
in this form without their valuable help, cooperation and guidance.
First and foremost, our sincere gratitude to our guide, Prof. C. R.Mehta, Department of
Electrical Engineering, Institute of Technology, Nirma University for guiding us in
investigations for this seminar. Our numerous discussions with his were extremely helpful.
We express our sincere gratitude to Prof. Sarika S Kanojia, Department of Electrical
Engineering, Institute of Technology, Nirma University for her valuable suggestions and
guidance throughout the period of this seminar.
The seminar on “Air Insulated and Gas Insulated Substation” was very helpful to us in giving
the necessary background information and inspiration in choosing this topic for the seminar. Our
sincere thanks to Prof. Gaurang Buch and Prof. Sukanta Sahoo Seminar Coordinator for
having supported the work related to this project.
Last but not least, our classmates who made valuable comment suggestions on this proposal
which gave us an inspiration to improve our work. We thank all the people for their help directly
and indirectly to complete our work.
Special Thanks to Microsoft Office 2007.
Place: Ahmedabad Raj Patel
Pathik Patel
AIS & GIS Page 3
ABSTRACT
Reliable and economical power transmission and distribution are key functions for the future
electric power supply. Air insulated Substation requires more space and more danger to faults.
So, Gas insulated switchgear is used in industrial areas to fulfill high-energy demands by space
saving design with a minimum of cost. Only SF6 insulated switchgear is able to fulfill these
requirements. SF6 switchgear installed in Canada in a 550 kV substation with 100 kA as the
highest breaking capacity ever achieved in one of the steps of development since then.
Consistent research and development and innovative energy led to the third generation of
nowadays compact and overall optimized switchgear. The advantages of gas-insulated
switchgear are its compact design and the modular system. The standardized modular structure is
made to match the various customers specifications and allows to realize almost all substation
configurations in compliance to them.
AIS & GIS Page 4
LIST OF FIGURES
1) Fig.1.1 (A) Air Insulated Substation
2) Fig.1.1 (B) Gas Insulated Substation
3) Fig.1.2 (A) Pole Mounted Substation
4) Fig.1.2 (B) Traction Substation
5) Fig. 1.3 ELECTRICAL DISTRIBUTION NETWORK
6) Fig. 2.1.4 Protective Relays
7) Fig. 2.1.6 (a) Pin Type Insulator
8) Fig. 2.1.6 (b) Suspension Disc Insulator
9) Fig. 2.1.6 (c) Strain type Insulator
10)Fig. 2.1.7 Lightning Arrestor
AIS & GIS Page 5
NOMENCLATURE/ABBREVIATIONS
1) AIS - Air Insulated Substation
2) GIS – Gas Insulated Substation
AIS & GIS Page 6
TABLE OF CONTENTS
ACKNOWLEDGEMENT (2) ABSTRACT (3) LIST OF FIGURES (4) NOMENCLATURE/ABBREVIATIONS (5) TABLE OF CONTENTS (6)
CHAPTER 1: INTRODUCTION (8)
1.1 INTRODUCTION TO SUBSTATION
1.2 TYPES OF SUBSTATION
1.3 BLOCK DIAGRAMS OF ELECTRICAL
DISTRIBUTION NETWORK
1.4 SITE SELECTION FOR SUBSTATION
CHAPTER 2: SUBSTATION EQUIPMENTS (13)
CHAPTER 3: COMPARISION OF AIS AND GIS (18)
CHAPTER 4: CONCLUSION AND FUTURE SCOPE (21)
REFERENCES (22)
AIS & GIS Page 7
AIS & GIS Page 8
CHAPTER 1: INTRODUCTION
1.1 INTRODUCTION TO SUBSTATION
What is a Substation??
A Substation is a part of an electrical generation, transmission, and distribution system.
Substations transform voltage from high to low, or the reverse, or perform any of several
other important functions.
Between the generating station and consumer, electric power may flow through several
substations at different voltage levels.
Globally economy and population continues to grow, results, rise in electrical power
requirements. For this purpose, substation equipment has to be made more efficient and reliable
to cope up with increase in demand, specially adapting current power distribution and
transmission system.
Air insulated Substation:-
An electric power substation that has the busbars and equipment terminations generally open to a
ir and utilizes insulation properties ofambient air for insulation to ground.
Gas insulated Substation:-
A Gas insulated substation (GIS) is a high voltage substation in which the major
structures are contained in a sealed environment with sulfur hexafluoride gas as the
insulating medium.
All the equipments are placed inside SF6 modules filled with SF6 gas.
GIS technology originated in Japan, where there was a need to develop technology to
make substations as compact as possible.
Gas Insulated Substations are high voltage Substations that are compact, requiring little
maintenance when compared to air-insulated conventional Substations.
AIS & GIS Page 9
1.2 TYPES OF SUBSTATION
Classification Based on Configuration, e.g.:
1) Conventional Air Insulated outdoor substation,
2) SF-6 Gas Insulated Substation,
3) Composite Substations having combination of above two.
Classification Based on Voltage levels, e.g.:
A.C. Substation: EHV, HV, MV, LV; HVDC Substation.
Classification Based on Outdoor or Indoor:
Outdoor Substation is Under Open Sky.
Indoor Substation is inside the building or in ground.
Pole mounted Substation:-
Fig.1.1 (A) Air Insulated
Substation
Fig.1.1 (B) Gas Insulated Substation
AIS & GIS Page 10
Pole mounted substation are mainly distribution substation constructed on two pole
Traction Substation:-
Electrified Railways use distributed and Transmission Substation.
For DC trains, Rectifier (Mercury) based Substation.
For AC trains, Rotary converters are used.
Fig. 1.2 (A) Pole mounted Substation
Fig. 1.2 (B) Traction Substation
AIS & GIS Page 11
1.3 BLOCK DIAGRAMS OF ELECTRICAL DISTRIBUTION NETWORK
Fig. 1.3 ELECTRICAL
DISTRIBUTION NETWORK
AIS & GIS Page 12
1.2 SITE SELECTION:-
It should be located at the centre of gravity of load.
It should involve minimum capital cost.
It should provide safe and reliable arrangement.
There should be space for future expansion.
There should be enough space for accessing incoming and outgoing lines.
AIS & GIS Page 13
CHAPTER 2 SUBSTAION EQUIPMENTS
2.1 Equipments used in Substation
The major equipments and accessories that may be used in substation:--
1. Bus bar,
2. Circuit Breakers,
3. Isolators,
4. Protective Relays,
5. Transformers,
6. Insulators,
7. Lightning Arrester,
8. Current Transformers,
9. Potential Transformer,
10. Control room.
2.1.1 Bus Bar:-
The bus is a line in which the incoming feeders come into and get into the instruments for
further step up or step down.
Various Incoming and outgoing circuits are connected to Bus Bars.
There may be double line in the bus so that if any fault occurs in the one the other can
still have the current and the supply will not stop.
The Cross Section of the bus bar is to be decided as follows :
1) It should be able to carry the current without any heating so that maximum temperature
doesn’t exceed 700C.
2) The current capacity generally adopted as 200 amp/mm2.
3) Corona must not be formed at normal operating voltage. To prevent corona hollow bus
bar is also used.
4) Mechanical force ∝ current I2 ∝ 1/ Spacing between two conductors
AIS & GIS Page 14
2.1.2 Circuit Breakers
Circuit breaker is used for switching during normal and abnormal conditions.
It is used to interrupt short circuit currents and connected in series with circuit.
There are many types of circuit breakers.
1) Air blast circuit breaker
2) Oil circuit breaker
3) SF-6 circuit breaker
2.1.3 Isolators
Mainly Used when repairing and maintenance of substation has to be carried out.
Operated on No load as circuit breakers are used for On Load.
2.1.4 Protective Relays
Employed to give protection to the equipments against abnormal conditions and faults in
the power system.
Isolates the faulty element from the system with the help of circuit breakers.
Fig. 2.1.4 Protective Relays
AIS & GIS Page 15
2.1.5 Transformers:
There are three transformers in the incoming feeders so that the three lines are step down
at the same time.
At the generation, it will be step-up transformer and at the distribution end, there will be
step-down transformer.
Transformer tanks up to 25 MVA capacity are generally oil filled.
And those of higher capacity are transported with N2 gas filled in transformer tank to
avoid the ingress of moisture.
2.1.6 Insulators:
There are mainly three types of insulator used as overhead insulator likewise
1. Pin Insulator
2. Suspension Insulator
3. Strain Insulator
Insulators serve two purposes
o They Support conductors (Bus Bar),
o Confine the current to the conductors.
Most Commonly used material for manufacture of insulator is porcelain.