Thomas Fernandes
description
Transcript of Thomas Fernandes
SERGI France – Smart Grid Middle East May 4th to 6t h 2009 Sergi Holding – Hanoi Electricity Conference – 5th December 2007 1/32
TRANSFORMER PROTECTOR
Thomas Thomas FernandesFernandes, Business Development Manager, Business Development Manager
SMART Grid Middle East SMART Grid Middle East -- Dubai UAE, May 4Dubai UAE, May 4th th to 6to 6thth, 2009, 2009
SERGI France, 186 av. du SERGI France, 186 av. du GGéénnééralral De Gaulle, 78260 De Gaulle, 78260 AchAchèèresres, France, Franceweb: web: www.sergiwww.sergi--france.comfrance.com, Office: (33) 1 39 22 48 71 , Fax: (33) 1 39 22 11 Office: (33) 1 39 22 48 71 , Fax: (33) 1 39 22 11 1111
TRANSFORMER PROTECTOR AN ANSWER TO PREVENT TRANSFORMER EXPLOSION
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
OIL FILLED TRANSFORMER EXPLOSIONS
Danger : Large quantity of Oil in contact with high voltage elements
low impedance fault transformer explosion and fire
GOAL : Prevent such dramatic explosions Protection of Transformers
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
TRANSFORMER TANK RUPTURE PREVENTION
� TRANSFORMER PROTECTOR (TP) Principle
� Physical Phenomena
� TP Operation
� Technical & Financial Benefits
� TP References
� Installation Examples
PLAN OF THE PRESENTATION
SUMMARY
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
The Principle :During a short circuit, the TP is activated within milliseconds by
the first dynamic pressure peak of the shock wave, avoiding transformer explosion before static pressure increa ses.
THE TRANSFORMER EXPLOSION PREVENTION THE PRINCIPLE
Avoiding transformer explosions before static pressure increases.
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
THE TRANSFORMER EXPLOSION PREVENTION THE PRINCIPLE
Tank Rupture
Pressure Wave / Structure Interaction
Dielectric Oil Insulation Rupture
Electric Arc
Oil Vaporization
Pressure Wave Propagation
Local Pressure Increase
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
Tank Rupture Prevented
Tank Depressurization
Pressure Wave / Structure Interaction
Dielectric Oil Insulation Rupture
Electric Arc
Oil Vaporization
Pressure Wave Propagation
Local Pressure Increase
TRANSFORMER PROTECTOR
THE TRANSFORMER EXPLOSION PREVENTION THE PRINCIPLE
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
The different components of the TP:
1. Depressurization Set
2. OLTC Depressurization Set
3. Oil-Gas Separation Tank
4. Explosive Gas Elimination Pipe
5. Cabinet
6. Explosive Gases Evacuation
7. Conservator Shutter
To create an evacuation opening before the dynamic pressure becomes uniform static pressure
5
62
4
7
31
THE TRANSFORMER EXPLOSION PREVENTION PRESENTATION
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
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1/ The dynamic pressure peak travels at the speed of sound inside oil
2/ Ruptureof the disk,depressurisation,evacuation of the oil-gases mixture
4/ Nitrogen injectionN2
3/ Opening of the air isolation shutter����
5/ Explosive gasesproduction is stopped after 45 min
THE TRANSFORMER EXPLOSION PREVENTION OPERATION
TP Operation
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
Experimental Investigations
THE TRANSFORMER EXPLOSION PREVENTION
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
Experiments
• 62 tests (28 with EDF, 34 with Cepel)
• Physical phenomena were highlighted
• The TP prevented the transformer explosion each time.
Simulation Tool
• Compressible 2 phase flow 3D modeling
• The model is validated against experimental data
• The TP operation is validated for large transformers.
The TP is activated within milliseconds by the firs t dynamic pressure peak avoiding transformer explosio n.
The Transformer Protection was designed to prevent transformer explosion
EXPERIMENTAL INVESTIGATIONS EXPERIMENTS
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
34 Live Tests
• In the CEPEL Laboratory (Brazil)
• 3 transformer sizes :Max distance between arc and TP:– T1: 8.5 m– T2: 6.0 m– T3: 6.2 m
EXPERIMENTAL INVESTIGATIONS EXPERIMENTS
T2 TRANSFORMER
T1 TRANSFORMER T3 TRANSFORMER
OGST
DEPRESSURIZATION SET
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
• 3 arc positions : A – B – C
34 Live Tests
• In the CEPEL Laboratory (Brazil)
• 3 transformer sizes :Max distance between arc and TP:– T1: 8.5 m– T2: 6.0 m– T3: 6.2 m
EXPERIMENTAL INVESTIGATIONS EXPERIMENTS
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
• Current range : 5 – 15 kA
• Time : 83 ms
• Arc Energy : up to 2.5 MJ
• 3 arc positions : A – B – C
34 Live Tests
• In the CEPEL Laboratory (Brazil)
• 3 transformer sizes :Max distance between arc and TP:– T1: 8.5 m– T2: 6.0 m– T3: 6.2 m
EXPERIMENTAL INVESTIGATIONS EXPERIMENTS
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
EXPERIMENTAL INVESTIGATIONS TEST MOVIE
Movies of the TP Operation
Test number: 30Reference: 30_T1C_140_83_ATMArc: 14000 A during 83 msArc Location: Opposite the TP close to the bottom (pos. C)Transformer weight: 72 tonsCamera Speed: 25 frames/sec
Acceleration: 400 g
Test number: 28Reference: 28_T1A_140_83_ATMArc: 14800 A during 83 msArc Location: At the cover, in the TP vicinity (pos. A)Transformer weight: 72 tonsCamera Speed: 25 frames/sec
Acceleration: 400 g
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
TRANSFORMER EXPLOSION PREVENTION
Physical Phenomena Creation of an electrical arc
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0 ms : Start of applied current
3.66 ms : Bubble generation
4 ms : Bubble volume = 9 cm3, 0.5 in.3
4.33 ms : Bubble volume = 60 cm3, 3.7 in.3
4.66 ms : Bubble volume = 97 cm3, 5.9 in.3
5 ms : Bubble volume = 190 cm3, 11.6 in.3
5.33 ms : Bubble volume = 299 cm3, 18.2 in.3
5.66 ms : Bubble volume = 399 cm3, 24.3 in.3
6 ms : Bubble volume = 568 cm3, 34.7 in.3
6.33 ms : The electrical arc ignites and creates t he first dynamic pressure peak of the shock wave
TRANSFORMER EXPLOSION PREVENTIONEXPERIMENTAL INVESTIGATIONS GAS GENERATION
ARC IGNITION, 2500 A, FILMED WITH A HIGH-SPEED CAME RA(3000 FPS)
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
EXPERIMENTAL INVESTIGATIONS GAS GENERATION
Test Number: 3
Test Reference: 2002
Arc Current: 2500 A
Arc Duration: 79 ms
Camera Speed: 3000 frames/second
• Gas bubbles appear on the arc path (1 to 2.3 m3 i.e. 35 to 80 ft3).
• Gas gets under pressure (from 100 bar/sec to 5,000 bar/sec i.e.14,500 psi/sec to 72,500 psi/sec)
• The dynamic pressure rises up to 14 bars (200 psi).
• Movie (EDF Tests):
The electrical arc creates a very violent physical phenomena with tank acceleration up to 800g, where g=9.81 m/sec² i. e. 30 ft/sec².
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
EXPERIMENTAL INVESTIGATIONS GAS GENERATION
Progressively, vaporization is increasingly difficu lt because the arcis mostly surrounded by gas ⇒⇒⇒⇒ a logarithmic extrapolation
Geração de Gás X Energia do Arco
0,0
0,5
1,0
1,5
2,0
2,5
3,0
3,5
4,0
4,5
5,0
0 10 20 30 40 50 60 70 80 90 100
Energia do Arco (MJ)
Vol
ume
de G
ás (
m3)
V - Gas Volume (m3)
E - Arc Energy (J)
Gas Generation versus Energy
Arc Energy (MJ)
Vol
ume
of G
as (
m3 )
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
TRANSFORMER EXPLOSION PREVENTION
Comparison Between Dynamic and Static Pressure
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
SIMULATION OF PRESSURE WAVE PROPAGATION
EXPERIMENTAL INVESTIGATIONS PRESSURE
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
HOW THE STATIC PRESSURE IS BUILT UP
Simulation of Test n.º 31 of CEPEL:
� Maximum Current, 34,5kA
� Maximum Voltage, 1034V
� Arc Energy, 460 kJoule
� Arc Duration, 83 milliseconds
� The tank withstands a maximum static pressure of 17 psi (1.2 bar) under atmospheric pressure
� For this test, pressure would stabilize at 88 psi (6 bar) above atmospheric pressure if not equipped with TP
The figure shows evolution of internal dynamic pressure inside of transformer tank if not protected by the TP
EXPERIMENTAL INVESTIGATIONS PRESSURE
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
Test Number: 32
Arc Current: 14,000 A
Arc Duration: 83 ms
Arc Location: at the tank cover in the TP vicinity (A)
Under Atmospheric Pressure
Pressure Peak
109 psi (7.5 bar)
Pressure Gradient
56,550 psi/s
3,900 bar/s
PRESSURE VARIATION DURING TP OPERATION
EXPERIMENTAL INVESTIGATIONS PRESSURE
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
Simulations without TPExperiments with TP
Test 31
D
Initial conditions: 450 kJ arc generating 1.9 m3 of gas
• Pressure reaches a static value higher than the static withstand limit
• Pressure remains at these levels for a long time.
The tank explodes when it is not equipped with a TP.
EXPERIMENTAL INVESTIGATIONS PRESSURE
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
Computational Investigations
COMPUTATIONAL INVESTIGATIONS 400 MVA TRANSFORMER
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
10 INCHES RUPTURE DISK
150,000 ELEMENTS
Approximately 1 Liter / Element
TP CONFIGURATION
COMPUTATIONAL INVESTIGATIONS 400 MVA TRANSFORMER
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
WITHOUT TRANFORMER PROTECTION
ELECTRICAL ARC, 80kA 110ms, 11MJ
GAS BUBBLE 3.3M3
P (bar) v (m/s)
Dimensions: 7.8m x 4m x 3.2m , Arc: 11 MJ
COMPUTATIONAL INVESTIGATIONS 400 MVA TRANSFORMER
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
WITHOUT TRANFORMER PROTECTION
The max pressure is about 15 bars near a bushingThe static pressure stabilizes at around 8 bars after 500 ms
the transformer explodes.
P (bar) v (m/s)
T=2.5ms T=20ms T=50ms
T=120ms T=200ms
COMPUTATIONAL INVESTIGATIONS 400 MVA TRANSFORMER
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
P (bar) v (m/s)
WITH TRANFORMER PROTECTION
Dimensions: 7.8m x 4m x 3.2m , Arc: 11 MJ, TP diame ter: 0.25m (10”)
COMPUTATIONAL INVESTIGATIONS 400 MVA TRANSFORMER
DEPRESSURISATION SET
ELECTRICAL ARC, 80kA 110ms, 11MJ
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
WITH TRANFORMER PROTECTION
The TP depressurizes the transformer in 130 ms
P (bar) v (m/s)T=2.5ms T=20ms T=50ms
T=120ms T=200ms
COMPUTATIONAL INVESTIGATIONS 400 MVA TRANSFORMER
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
With TP, far from the arcWith TP, close to the arc
COMPUTATIONAL INVESTIGATIONS COMPARISON
Comparison of the pressure distribution after 120 ms with and without TP
Without TP
P (bar)
• With TP , the first dynamic pressure peak of the shock wave activated the TP within milliseconds before static pressure is built up.
the transformer is safe .
• Without TP , the max pressure is 15 bars and the static pressure builds up at around 8 bars the tank explodes.
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
Comparison between the TRANSFORMER PROTECTOR and the Pressure Relief Valve
EXPERIMENTAL INVESTIGATIONS PRESSU RE RELIEF VALVE
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
PRV AND TP COMPARISON TO STATIC AND DYNAMIC PRESSUR E
TRANSFORMER TANKS UNDER INTERNAL PRESSURE
� The TRANSFORMER PROTECTOR (TP) operates before tank wall inertia is overcome by the dynamic pressure and prevents tank rupture
� The PRV cannot respond to dynamic pressure because of:
- Spring inertia: 5 milliseconds
- The very small evacuation section
at the beginning of the opening:
15% when PRV 50% opened
- U turn for oil evacuation
EXPERIMENTAL INVESTIGATIONS PRESSU RE RELIEF VALVE
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
Very transient phenomenon, rate of rise from 360 psi/s to 72,500 psi/s, 25 bar/s to
5,000 bar/s
Very strong moving forces that tank can withstand because of inertia to break
Dynamic Behavior
TRANSFORMER PROTECTOR
Pressure spatially non-uniform
Very high local dynamic overpressure < 200 psi, 14 bar
Local and moving mechanical stresses
PRV AND TP HAVE DIFFERENT OPERATING CHARACTERISTICS TO RESPOND TO DIFFERENT PHENOMENA
Uniform mechanical stresses
Static Behavior
PRESSURE RELIEF VALVE
Very slow phenomenon, rate of rise below 360 psi/s, 25 bar/s
Pressure spatially uniform
Low global static overpressure, < 14.5 psi, 1 bar
Strong forces applied on all walls leading to tank rupture
EXPERIMENTAL INVESTIGATIONS PRESSU RE RELIEF VALVE
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
Video of Gas Bubble Escaping from the Transformer after Tank Rupture
EXPERIMENTAL INVESTIGATIONS GAS GENERATION
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
� The gas bubble travels through the plant, up 2 sets of stairs , looking for oxygen and finds the door.
� There is so much energy that the door is blown off and is found 100 m away.
� The diameter of the gas bubble is approx. 4.9 ft (1.5 m) across. This translates to 62.4 ft3 (1.8 m3) of gas.
� According the energy vs. volume curve, this volume corresponds to an electrical arc energy of 0.8 MJ.
� This is a very small short circuit.
EXPERIMENTAL INVESTIGATIONS GAS GENERATION
VIDEO OF GAS BUBBLE AFTER TANK RUPTURE
� The following video shows the gas bubble that is created when there is an electrical arc in the transformer .
� Because the transformer was not protected by a TRANSFORMER PROTECTOR, the tank ruptured and the gas escapes.
� Around the edge of the gas bubble, the gas comes into contact with the oxygen and catches fire.
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
•The temperature of the fireball is approximately 27 00o F (1500o C ). The bubble has burned all of the plant equipment that was in it’s path, the light was quickly shut off.
•The conventional protections did not work:
•The security door, supposed to contain the fire in the bunker, closed well after the bubble escaped
•The fire protection equipment, including the water spray system, was not activated.
•Two people tried to escape. They were fortunate in that they were only badly burned and were not killed in the fire.
•The whole power plant (1,350 MW) was out of service for 4 months. The damaged section (450 MW) was out of service for more 13 months.
EXPERIMENTAL INVESTIGATIONS GAS GENERATION
VIDEO OF GAS BUBBLE AFTER TANK RUPTURE
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
Technical and Financial Benefits
FINANCIAL BENEFIT
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
☛ The TRANSFORMER PROTECTOR is a passive mechanical sy stem , which can only be activated by the level of the transformer tank inte rnal pressure reached during short-circuits.
☛ The TRANSFORMER PROTECTOR has therefore a very high reliability,as false activation is impossible.
☛ On request, nitrogen can be injected manually to eliminate all actuators.
Financial Benefits – RELIABILITY
FINANCIAL BENEFIT
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
MAJOR TRANSFORMER POLLUTION CASES
INCIDENT POLLUTION CONSEQUENCES
COST INFORMATION
(MUSD)
Binghamton, NY
1981
PCB contamination of an 18-story state office building
Clean-up 53
Lawsuit 100
Warren County, VA
1985
PCB contamination of the Shenandoah River
Clean-up 40
Environmental penalty
6.5
New Paltz, NY
1991
PCB Contamination of the SUNY New Paltz campus
Clean-up 50
Lawsuit 73
TRANSFORMER PROTECTIONFINANCIAL BENEFIT
Financial Benefits – Cost of LITIGATION
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
•The cost of the TRANSFORMER PROTECTOR is a fraction of the cost of an explosion.
•During an internet search for 1 year, SERGI found more than 730 transformer explosions in the US alone.
FINANCIAL BENEFIT
Financial Benefits – Cost of the TRANSFORMER PROTECT OR
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
� The TRANSFORMER PROTECTOR acts before any damage is done.
TRANSFORMER PROTECTOR TECHNOLOGY :
� In terms of damage cost reduction, the TRANSFORMER PROTECTOR offers three main advantages:
• It saves all surrounding equipment and buildings from
explosion and fire;
• It leaves the environment unharmed;
• It enables the quick internal repair of the transformer .
FINANCIAL BENEFIT
Financial Benefits – SUMMARY
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
As of December, 2008: (ref FfTPk)
- 1293 TRANSFORMER PROTECTORS have been sold
- in the world, 87 companies from 46 different count ries have included the TRANSFORMER PROTECTOR in their Technic al Specifications
NFPA Handbook – Processes and Facilities, Section 9, Chapter 14, Electric Generating Plant
The first TRANSFORMER PROTECTOR was sold in 2000 in Italy
TRANSFORMER PROTECTION
REFERENCES
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
TRANSFORMER PROTECTIONTRANSFORMER PROTECTION
Installation Examples
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
Cover and Side Manholes, Pressure Relief Valves and Existing Valves can be used for the adaptation of the Depressurization Set
DEPRESSURIZATION PIPING
RETROFITTING ON EXISTING TRANSFORMERS
The TRANSFORMER PROTECTOR is easily retrofitted with out tank machining by using the existing interfaces
TRANSFORMER PROTECTIONTRANSFORMER PROTECTION
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
OVERVIEW
TRANSFORMER PROTECTION
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
DEPRESSURIZATION SET
TRANSFORMER PROTECTION
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
OLTC EQUIPPED WITH OIL FILTRATION UNIT
TRANSFORMER PROTECTION
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
RETROFITTING ON EXISTING TRANSFORMERS
The TRANSFORMER PROTECTOR can be retrofitted on the Transformer cover by using a vertical Depressurization Set
� The TRANSFORMER PROTECTOR can be retrofitted on transformer cover by replacing the Pressure Relief Valve by a T-piece and installing a Vertical Depressurization Set
� Any manhole available on the transformer can be used as a base for retrofitting of a Vertical or Horizontal Depressurization Set
TRANSFORMER PROTECTIONTRANSFORMER PROTECTION
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
DEPRESSURIZATION SET - TRANSFORMER
TRANSFORMER PROTECTION
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
THANK YOU FOR YOUR THANK YOU FOR YOUR THANK YOU FOR YOUR THANK YOU FOR YOUR
KIND ATTENTIONKIND ATTENTIONKIND ATTENTIONKIND ATTENTION
TRANSFORMER PROTECTION
SERGI France – Smart Grid Middle East May 4th to 6t h 2009
SERGI FRANCE186, Avenue du Général de Gaulle – P.O. Box 90
78260 Achères, France���� : (33) 1 39 22 48 67
���� : (33) 1 39 22 11 11
web site : www.sergi-france.com
Our Sales Area Manager : Mr. FERNANDES
TRANSFORMER PROTECTION