José Cano, August 2015
HiDry72
Dry power transformers for subtransmission level
© ABB Group - Confidential
September 1, 2015 | Slide 1
72
HiDry
Why?
Why HiDry72?
1. Safety
Incidents in oil
transformers due
to internal or
external causes
CIGRE 2013 “Guide for transformer fire
safety practices”:
* Power transformer fire rate ~0.1% per year
Incidents in GIT,
gas insulated
Transformers due
to gas leakages of
SF6
Why HiDry72?
2. Ecology
Why HiDry72?
3. Reliability
§
Based on:
§
Very high MTBF/ Zero failure rate up to date
§
Withstand shortcircuit test passed succesfully in
CESI (31,5 MVA, 66 / 20 kV with OLTC) in 2014
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HiDry
What?
What HiDry72
The scope
Rated power
Primary voltage
up to 63 MVA
up to 72.5 kV
325 kV for IEC 60076-11
Lightning impulse
350 kV for IEEE C57.12.01
voltage
(negative wave)
Short duration AC 140 kV
Secondary voltage
up to 36 kV
Connection group
Y or D
On load tap changer/ HV side
taps
17 positions (+ 8 x 1.25%)
Cooling
AN, ANAF, AFAF, AFWF
Enclosure (IP, or its IP00, IP21 (indoor) to IP54
NEMA equivalent)
or IPX4D (outdoor)
Partial discharge
Insulation class
Environmental class
Climatic class
Fire class
< 10pC
F (155°C) or H (180°C)
E2
C2
F1
What HiDry72
DETC, Tappings (off-load)
§
The standard number of positions is 5
(+/-2x2.5%). More positions can be
manufactured on request
§
Connections are normally bolted
What HiDry72
OLTC (on-load tap changer)
Characteristics of OLTC:
§
Dry, oil-free technology
§
Air contacts
§
Vacuum breaker
§
Suitable for linear type winding configuration
§
Installation on HV side.
§
Current design
§
(*) presently limited
availability, please
contact us for
clarification
For up to 17 positions and ±10% regulation
(*)
§
Max voltage step 900 V
§
Max current 500 A
§
Low maintenance
§
Increases transformer width due to higher
clearances in air
What HiDry72
Accesories
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HiDry
Where?
Where HiDry72
Applications areas
§
Urban (inner-city) substations
§
Indoor and underground substations (Basements)
§ Airports, Commercial, Buildings, Metro, etc.
§
Fire risk, even for outdoors installations
§ Indoor substation, National Parks and forests
§
Environmentally sensitive areas
§ Water reservoir
§ Water protection areas (rivers, lakes)
§ Islands
§ Forest
§
Heavy industry substations
§ Chemical, pulp&paper, oil&gas, metals&mines, etc
§
Renewable generation
§ Hydro, off-shore wind turbines, solar, etc
§
Retrofits
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HiDry
Customer value proposition
HiDry72
Customer value proposition (benefits)
1.
Safety: fire risk limited
2.
Ecological, no polution
3.
Reliability and excelent response
against shortcircuit
4.
Substation CAPEX is reduced in case
of indoors, due to savings:
1.
Civil Works
2.
Assembly on site
3.
Anti fire systems
5.
Reduced operation and maintenance
6.
Insurance savings
7.
Easy repair on site
What HiDry72
Advantages and benefits
Safety
§
No flammable liquids:
§
no explosion,
§
no self-igniting materials,
§
no spread of fire by burning liquid
§
F1 fire behavior class: restricted flammability and minimized emission of toxic substances
or opaque smokes
§
10-20 times smaller combustible mass than oil transformer: mainly epoxy resin of coils:
§
§
Does not ignite, but degas due to external heat source
§
Thermosetting polymer, not melting, coil keeps shape
§
Filled with silica, absorbing heat
§
Fire extinguishes when external heat source removed
§
Self-extinguishing solid insulation
No SF6 gas leakages
What HiDry72
Upgraded technical performance
§
Great resistance to short circuit effects (thermal and dynamic)
§
Great performance towards seismic phenomenon and vibrations
§
Great capacity to support overloads (IEC 60076-12, ANSI C57.961999)
§
More ability to withstand overcurrents arising from applications
§
The highest dielectric strength for dry transformers. Tested BIL up to 380 kV.
§
The best suited for damp and contaminated industrial areas (E2).
§
Suitable for operation, transport and storage at ambient temperature down to 25 ºC (C2), even tested up to -50 ºC.
What HiDry72
Advantages and benefits
Environmentally friendly and cost efficient
§
Optimized load loss
§
Lower infrastructural cost. Simple installation,
no special civil works
§
Minimal requirements for safety and protection
installations
§
Very low maintenance
§
Easier unload and more efficient logistic costs
§
Easy repair at site
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HiDry
FAQs
FAQ, HiDry72
Oil vs dry footprint and weight
Length (mm)
Length (in)
Width (mm)
Width (in)
Height (mm)
Height (in)
Weight (kg)
Weight (lb)
25 MVA, 66/10 kV
Dry type,
Oil filled
DETC
4,370.0
4,500.0
172.0
177.2
2,000.0
2,300.0
78.7
90.6
4,120.0
4,100.0
162.2
161.4
57,200.0
42,000.0
126,104.0
92,500.0
40 MVA, 66/10 kV
Dry type,
Oil filled
DETC
4,970.0
5,000.0
195.3
196.5
2,000.0
2,500.0
78.6
98.3
4,120.0
4,100.0
161.9
161.1
79,800.0
61,000.0
175,928.0
134,500.0
§
When rated power is increasing, then comparison oil-dry is reduced.
§
Dry-type needs a slightly bigger perimeter around, due to air-to-air clearances.
FAQ, HiDry72
Layout/perimeter
•
For safety reasons, there
must be a fence around the
set transformer - OLTC, at
500 mm.
•
In case of limited space, it is
not necesary any inspection
under load. Anyway the direct
access to the transformer
must be forbidden when
enegized
•
Easy access to control box
(Temperature, motor drive
OLTC, …)
•
Since the OLTC frame is
grounded, it can “touch” the
walls arround, keeping the
minimum clearances
FAQ, HiDry72
Cooling
•
The transformer must be located at
least 200-300mm from the cell walls for
effective cooling
•
HV&LV connections must be at least
630mm from the cell roof and walls
•
The in (A) and out (B) surfaces have at
least the surface áreas in m2 given by
the following formula:
A = 0,185 * P / sqrt (h)
B = 1,15 * A
B
Where:
•
•
P: Sum of non-load and full loadlosses of the transformer in kW
H: Effective height for cooling in m
•
In case there is no enough
surface, then heat extraction is
mandatory. Air conditioned
would be an option.
FAQ, HiDry72
Maintenance
Transformer:
§
Annually: transformers in normal environments
Vacuum cleaner or by blowing with dry air or nitrogen (maximum pressure 3
Kg/cm2)
Check and tighten screws, connections, and coil support blocks
Check the thermal protection device that includes the sensors and the
measuring control unit
In case of OLTC:
§
§
Recommended maintenance:
§
100.000 operations or 3 years, lubrications of internal parts and checking of
screws.
§
200.000 operations, checking of vacuum breaker.
§
300.000 operations, replace vacuum breaker + contacts
§
800.000 operations, replace OLTC
Savings in time and money.
FAQ, HiDry72
Noise level
•
Normally, dry-type transformers present higher
noise level (abt 10-20% but depending on
designs)
•
Why:
•
•
•
Bigger core.
Neither oil nor tank muffling noise level.
Sollutions:
• Reduced noise level design (low induction)
• Installation of absorbing sound material in
the installation / room
Example:. 30 MVA 66/22 above indicated (standard
induction):
Oil filled acoustic pressure: 60 dB
HiDry72 acoustic pressure: ≤ 75 dB
FAQ, HiDry72
Overloads
IEC 60076-12 INTERNATIONAL STANDARD
Power transformers –
Part 12: Loading guide for dry-type power transformers
Overload capability in a 12 MVA, 66/22kV, OLTC
§
Each transformer has individualized overload capability curves, that will
depend on its design (mass of conductors and mass of dielectric
materials)
§
When customer requires specific overloads they will be considered
during sizing of the transformer by engineering
FAQ, HiDry72
Life expectancy
IEC 60076-12
INTERNATIONAL
STANDARD
Power transformers –
Part 12: Loading guide for dry-type
power transformers
IEEE Std C57.96™
Guide for Loading Dry-Type
Distribution and Power
Transformers
• IEC 60076-12 and IEEE C57.96
indicate the way to determine the
lifespam on dry type transformers,
taken into account:
• Isolation material ageing ratio.
• Calculation of loss of life.
• The estimated life expectancy is
about 20 years (180000 hours), at
least, working at nominal conditions
• A temperature increase of 6K
doubles the ageing rate.
• A temperature reduction of 6K
reduces in half the ageing rate.
• For oil transformers (IEC 60076-7) is
the same life expectancy
FAQ, HiDry72
Overvoltage
§
No damages in case of the transformer is overexcited by 5%
(voltage) continuously.
§
Overvoltage causes a higher temperature in the core, it is
recommended by IEC/ANSI, to:
§
Consider it just in emergency / temporarily cases.
§
In any case transformer can withstand transient overvoltages from
10-40%, that must be verified according to the specification (FEM
must be done)
§ 10%
1 min
§ 20%
30-50s
§ 40%
5-10s
§ >40% ms
§
Same approach is valid for oil & dry type transformers, due to the
fact that this effect is just related to the core induction.
FAQ, HiDry72
Recyclability
(*) With seaworthy (maritime) packing, the percentage of wood ascends considerably
•
At the end of the
transformer lifetime, the
cast resin is considered
as an urban waste.
•
Don’t need special
destruction operations or
certification.
FAQ, HiDry72
Repair at site
•
•
•
Modular assembly.
Easy replacement.
Don’t need to change a full
column.
FAQ, HiDry72
Repair at site
• Dry transformers have a very big
advantage, since they are able to be
repaired at site, with standard means:
• In case that one of the coils failed, it
could be replaced easily, like at
factory.
• Spare coils are tested at factory before
delivery.
• Just needed field test after repair are:
• Megger
• Ratio
• Resistance
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HiDry
Configuration switchgear –
dry power transformer
FAQ, HiDry72
Configuration switchgear – dry power transformer
FAQ, HiDry72
Configuration switchgear – dry power transformer
FAQ, HiDry72
Configuration switchgear – dry power transformer
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HiDry :
business case
Endesa-Sevilla: the safest
urban substation in Spain
HiDry72
Transformer installed in Sevilla (inner-city substation)
Customer need
§
4 x 31500 kVA, 66 / 22kV OLTC
(+8 x 1.25%) for replacing oil
transformers in the substation
ABB response
§
Dry VCC transformers for main
substation (head)
§
An innovating and improved
solution
Customer benefits
§
Safety for people and fire hazard in
urban area
§
Environmental and ecological
HiDry72
Transformer installed in Sevilla (inner-city substation)
HiDry72
Transformer installed in Sevilla (inner-city substation)
HiDry72
Transformer installed in Sevilla (inner-city substation)
HiDry72
Transformer installed in Sevilla (inner-city substation)
HiDry72
Transformer installed in Sevilla (inner-city substation)
HiDry72
Transformer installed in Sevilla (inner-city substation)
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HiDry :
business case
Fonte Nova Arena –
Salvador de Bahía: the
safest urban substation in
America
HiDry72: outstanding success story
Brazil, ABB PS, Coelba, Fonte Nova Stadium-Salvador
Customer need
§
2 x 25000 kVA, 69 / 13.8-11.9 kV
OLTC (+4-12 x 1.25%) for main
substation
ABB response
§
Dry VCC transformers for main
substation (head)
§
An innovating and improved
solution
Customer benefits
§
Safety for people and fire hazard
§
Environmental and ecological
§
Savings in the installation and operation
HiDry72
Fontenova Stadium
HiDry72
Fontenova Stadium
HiDry72
Fontenova Stadium
HiDry72
Fontenova Stadium
HiDry72
Fontenova Stadium
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HiDry
Summary
HiDry72
Take away messages
§
HiDry72 is a dry-type power transformer, with the same funcionality
than the traditional oil-type transformer
§
Tailorized engineering solution for those applications where the
conventional oil/gas transformers are not able to reach the required
levels of safety and ecology
§
Best choice for indoor/underground substations
§
Up to date, good experience with dry-type power transformers in 72
kV, with a very reliable solution
© ABB Group
September 1, 2015 | Slide 51