dry type transformers-ideal for fpso - abb ltd type transformers-ideal for fpso - transformers for...
TRANSCRIPT
© ABB Group September 24, 2009 | Slide 1
Dry type transformers-ideal for FPSO- Transformers for electrical and drive
systems
Arild Furnes,ATPA OGP/Petrobras workshop, 22.09.09
© ABB Group September 24, 2009 | Slide 2
Transformers for Ships and Offshore - Standards
IEC 60092-303 “ Electrical installations in ships, Part 303 equipment -Transformers for power and lighting”IEC 61892-3 “ Mobile and fixed offshore units, Part 3 equipment -Clause 5 -Transformers for power and lighting”
Both refer to general transformer standards IEC 60076 (all types) and IEC
60726 (Dry type transformers)
“Preferably air cooled dry type”
Liquid-immersed transformers “preferably hermetically sealed type, no spilling of liquid”
© ABB Group September 24, 2009 | Slide 3
Transformers for Ships and Offshore - StandardsDifferences to be noticed to on shore applications
Environmental conditions
Air temperature higher (45 C or higher) = reduced temperature rise
Cooling water temperatures high = reduced temperature rise
Humidity and salt = degrees of enclosure
Inclinations, static and dynamic = mechanic requirements
Acceleration and vibrations = mechanic requirements, flexible connections
EX-classified zones = specifically designed transformers
Materials to be used
Self extinguishing
High tracking index
Halogen free
© ABB Group September 24, 2009 | Slide 4
Classification often required /ABS, DnV, Rina, Loyds etc)
Type testing and special tests often required. Routine tests mandatory according to IEC.
Insulation between HV and LV systems
Normal practise to have earthed screen between HV and LV windings
Reduces capacitively transferred overvoltages fro HV side to LV ITsystems
Reduces transferred EMC disturbance from drive systems to ship distribution system
Screen is technically clear requirement, “increased” or “improved” insulation of HV systems is not
Drive supply transformers should have the screen for EMC reduction, all high power drives make EMC-noise to supply network
Screen inside transformer is economic way to block EMC
Transformers for Ships and Offshore - StandardsDifferences to be noticed to on shore applications
© ABB Group September 24, 2009 | Slide 5
Transformers for Ships and Offshore - StandardsDry transformers-Technologies
Dry type transformers IEC 60726Fire class F0,F1,F2For ships only possibility F1 (self extinguishing), F2 should be able operate under fire for limited time is not existingImpulse voltage level according to list 2 (higher alternative)Vacuum breakers create switching over voltages, more margin
3,6 kV = LI 40 kV7,2 kV = LI 60 kV12 kV = LI 75 kVtransformers at end of short cables (100-200 m) criticalIf the LI level is not mentioned, you may be getting the lower one ie list 1Classification rules have no impulse voltage requirementsArea to be improved
Dry type transformers cannot be installed without extensive measures on Explosion Hazard Zones at all, but must be installed on Safe AreasTemperature hot spots on coils, Sparking and charging at switching on
© ABB Group September 24, 2009 | Slide 6
Transformers for Ships and Offshore - StandardsDry transformers-Technologies
Dry type transformers IEC 60726Encapsulated type = resin encapsulated (cast resin or filament wound inside resin)Non-encapsulated types =open wound (traditional, with limitation)Environmental class E0, E1,E2For ships minimum E1 ,can be energised while having moisture on the transformer coils, but note that in the standard no switching overvoltage is considered (known to be a problem with vacumbreakers of certain designs in small offshore networks)E2 recommended (can operate while humidity is being sprayed on the transformer, has more margin compared to E1)E1 and E2 can be reached only with encapsulated designsClimatic class C1,C2
For ships minimum C1 (-5 C) is sufficientFor scandinavian Yards C2 (-25 C) is necessary while building ships
© ABB Group September 24, 2009 | Slide 7
Most common variants of dry type transformers Other important considerations
Rectifier duty. Derating approx. 20 % with6 puls diode rectifier.
Primary phase shiftremoves possibility for tapping, no-load voltageneeds to be carefullyselected from system study
Several cooling alternatives available for both dry type
AN, AN/AF, AF/AF, AF/WF
Ingress protection of enclosure
The higer number, biggerunit not to exceed thermallimits
Two dry type transformers in common enclosurefor 24 pulse rectiferduty.
Petrobras requiresdedicated enclosureas per today.
© ABB Group September 24, 2009 | Slide 8
Most common variants of dry type transformers Other important considerations
Both size and audible noisecan be reduced by material selection and design.
High grade orientend core steel
High grade copper wire or foil
High impedance many turns, low impedance fewer turns
Influences the physicaldimensions
Vacum cast coil
© ABB Group September 24, 2009 | Slide 9
Most common variants of dry type transformers Dry VPI open wound with paper
Recommendations for offshore applications
Only for LV distribution
Below 500 kVA AN
Indoor in controlled environment
Salt laden air will degrade
paper insulation over time
Up to approx 12 MVA
15 kV
Several cooling options available
Both Cu and Al windings available
Cost efficient
Petrobrasspecifications in general calls for resin encapsulated types
© ABB Group September 24, 2009 | Slide 10
Most common variants of dry type transformers Vacum Cast Coil
Classes: E2, C2, F1
Partial discharges: <10 pC
Insulation : 155ºC (F), 180ºC (H)
Design Temperature: 40 ºC
Up to approx 30 MVA
50 kV
Several cooling options available
Both Cu and Al windings available
Manufactured by all major suppliers
© ABB Group September 24, 2009 | Slide 11
Most common variants of dry type transformers Resibloc
Classes: E2, C2, F1
Partial discharges close to zero
Insulation : 155ºC (F), 180ºC (H)
Design Temperature: 40 ºC
Design according to class up to 55 ºC amb. or 38 ºC for cooling water.
Up to approx 40 MVA
45 kV
Several cooling options available
Both Cu and Al windings available
Glass-fiber reinforced, crack free
Wound resin impregnated coil
© ABB Group September 24, 2009 | Slide 12
MTBF Resibloc Transformers433 years !
© ABB Group September 24, 2009 | Slide 13
Resibloc TransformersTechnology highlights
© ABB Group September 24, 2009 | Slide 14
Why use dry type transformers on FPSO
Easy to install, simple foundation and enclosure
Very clean, no oil, pits etc.
Less fire load (energy) than oil filled
Epoxy has higher ignition temp than special synthetic ester
Can be assembled offshore by skilled service people
Easy to connect cables and/or bus-ducts
Easy access for inspection through bolted covers or hinged doors
Easy to install fans later to increase power if provisions (Space under coils) are made. Approx. 30 – 40 % increase
Practically maintenance free
© ABB Group September 24, 2009 | Slide 15
Why use dry type transformers on FPSOAreas to consider liquid filled transformers
Outdoor location in case of limited HVAC and indoor space
Highly corrosive offshore location. Tropical condition worse than cold in this matter. Exposed parts of Liquid filled are galvanized and painted.
Zone requirement
Dry type not suitable due to difficulties to ensure no hotspots on coils and sparking during energizing.
Very high power
Due to weight and size.
Multi winding transformers for drives (more than 3 secondaries due to balance of impedance/flux) Liquid filled are more flexible with respect to phase shift.
If OLTC (on load tap changer/AVR) is needed
Very large OLTC for dry types.
© ABB Group September 24, 2009 | Slide 16
Why use dry type transformers on FPSOLiquid filled application
Roof of FPSO E-house
Compact liquid filled
Corrugated tank design
Conservator type design
Zone 1 or 2 outdoor
FPSO outside West Africa.
Multi Phase Pump Power Control Module with drives inside
© ABB Group September 24, 2009 | Slide 17
Why use dry type transformers on FPSOLiquid filled execution
OF/WF transformer for propuplsion
Seawatercooled
Syntetic ester, biodegradeable
300 deg C flamepoint
Most compact design available,
Very beneficial on large compressor drives etc.
© ABB Group September 24, 2009 | Slide 18
Why use dry type transformers on FPSOLiquid filled on module outdoor
Single lift Power Control Module for subsea Multi Phase Pump
Liquid filled transformer installed outdoor on frame to reduce need for large cooling units inside module
© ABB Group September 24, 2009 | Slide 19
Dry type transformer with water cooling AF/WFIncreasing interest in the offshore and ship market
Reduces need for HVAC and ducts
Reduces audible noise
Approx. 5 % of losses to ambient, rest to water
Min. IP 44 design enclosure
Cooler for seawater available (double titanium tube)
Redundant blower and cooler arrangement available
No liquid carryingpipe allowed.
Clause 1.4 in PetrobrasI-ET-3000.00-5140-700-PCI-001ELECTRICAL BASIC DESIGN GUIDELINES
© ABB Group September 24, 2009 | Slide 20
Dry type transformers in a systemWhat can ABB do ?
Provide the best technologies available conforming with Petrobras specifications and applicable regulations.
Take responsibility for the integrity of the complete
Drive systems
Electrical system
Load flow calculations and considerations( impedance, no-load/nominal voltage of the transformer and voltage drop during DOL motor starts)
Harmonic calculations (THD)
Provide transformers which offers the best possible cancellation configuration with the VFD
Provide and dimension pre-magnetizing system for reducing inrush current when energizing the transformers
Up to 1/18 reduction of inrush current !
© ABB Group September 24, 2009 | Slide 21
Dry type transformers in a systemConfiguration of converter duty transformers
Distortion with 6 pulse
Distortion with 12 pulse
Distortion with 24 pulse
© ABB Group September 24, 2009 | Slide 22
Dry type transformers in a systemSimple pre-magnetizing system
T1
C2
C1
C3
T2 440 V
Simple and cost effective if back up supply available
Integrated in transformer enclosure
In Switchgear
Separate assembly
Figure of pre-magnetizing system in a essential mode drilling transformer to 690 V drilling drive system from weak 440V emergency supply network
© ABB Group September 24, 2009 | Slide 23
Dry type transformers in a systemPeregrino WHP’s
Total 10 units for water injection, booster and production pumps
ACS 1000i
24 pulse integrated dry type transformer
© ABB Group September 24, 2009 | Slide 24