PPT

1. SURGE ARRESTERS AND SURGE SUPPRESSORS
IN TRANSFORMER
Guided by:-
Er. SMRUTI PRAGYAN DALAI &
Er. UMESH CHANDRA MISHRA
Submitted by:-
Vikas Kumar Manjhi
Branch:-Electrical
Reg. No:-1201214203
Sec:-B

2. CONTENT
1) Introduction
2) Transformer
3) Lightning
4) Surge arresters in transformer
5) Types of surge arresters
6) How do surge arrester protect transformer
7) What exactly does a surge arrester do?
8) Advantage and disadvantage of surge arrester
9) Surge suppressor in transformer
10) How does surge suppressor protect

3. INTRODUCTION
SURGE ARRESTER:
 A device used on power system in high voltage, to protect
electrical equipments from lightning and switching surge .
 It is a surge diverter.
SURGE SUPPRESSOR:
 This is also a surge diverter but generally used in low
voltage equipments.
 It is generally used in electronics equipment.
This paper presents information about the characteristic
and design of arresters and suppressors.
In addition to applications, it also provides information
about the protection of transformer.

4. Transformer
As we all know that, “a transformer is a
static device which transfer electrical energy
from one circuit to another without change
in frequency’’.
Transformer are very important and costly
apparatus in power system.
Factor that can damage transformer
1) Lightning
2) Power frequency

5. Lightning
Lightning is a sudden electro static discharge
between two clouds during storm.
When lightning strike transmission line then a
very high voltage generated with in it.

6. This high voltage causes failure in the insulation
capacity of transformer .
Which result in the bursting of transformer or
other electrical device.
We can protect the transformer from lightning by
using
1. surge arrester
2. surge suppressor .

7. Surge arrester in transformer
 It protect transformer
from lightning and
switching surges.
 It is also called Surge
Protection Device(SPD).
 It is also used in power
transmission and
distribution system.

8. Types of arresters
Low-voltage surge arrester
Distribution arrester
DC or blowing valve-type arrester
Neutral protection arrester
 Magnetic blow valve station arrester

9. How do surge arresters protect transformer or
power system
11000 Volts
230 Volts

10. Typically
11000 Volts
230 Volts

11. Typically
11000 Volts
230 Volts
Surge arrester

12. Typically
11000 Volts
230 Volts
Surge arrester

13. What exactly does a surge
arrester do?
It does not absorb the lightning.
It does not stop the lightning.
It divert the lightning to ground.
It limit the voltage produced by lightning.
It only protects equipment electrically in
parallel with it.

14. At the Heart of all Arresters is the Metal
Oxide Varistor (MOV)
The MOV Disk is a semiconductor
that is sensitive to voltage .
At normal voltage the MOV Disk is an
insulator and will not conduct current.
But at higher voltage caused by
lightning it becomes a conductor.

15. The Metal Oxide Varistor (MOV) is a very fast acting
electronic switch.
It is an open switch to standard system AC voltage
and a closed switch to
Lightning voltages.

16. Advantage of surge arrester in transformer
The surge arrester protects the transformer.
The surge arrester alerts operator, when it is
damaged.
The surge arrester can be changed live line.
A healthy arrester is present at all times.

17. Disadvantage of surge arrester
Conducting surge arrester blow fuses.
Surge arrester has no live line capabilities.
Unsafe maintenance of surge arrester.

18. Surge suppressors in transformer
Surge suppressor (surge protector) is a device to
protect electrical devices from surge voltage.
It is also known as transient voltage surge suppressor
(TVSS).
This is also a surge diverter but used in low voltage
equipments.
 It is generally used in electronics equipment

19. How does surge suppressor
protect?
Blocking unwanted voltage or current.
Shorting to the ground.

20. What is surge voltage?
High amplitude
Short duration over voltage.

21. Reference:-
Sites:-
 www.electrical4u.com
 www.thefreedictionary.com
 www.wikipedia.com
Books
V Kamaraju(High Voltage Engineering)