Maintenance 2012
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Transcript of Maintenance 2012
On-Load Tap-Changer
Theoretical foundations
Maintenance of On-Load Tap-Changers
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
On-Load Tap Changer: OILTAP®
OLTC
-Tap selector
Diverter switch
insert
Type MS
OLTC
-Tap selector
OLTC Diverter switch
-insert
Type R
TAP CHANGER OPERATING
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 3
Motor Drive Unit
Tap Selector
Diverter Switch
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 4
Maschinenfabrik Reinhausen GmbHSwitching sequence
Load current IL
Circulating
current IK
Ik
Switching sequence Type M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 5
MCa MSCa TCa TCb MSCb MCb
MCa
MSCa
TCa
TCb
MSCb
MCb
Switching sequence Type M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 6
MCa MSCa TCa TCb MSCb MCb
MCa
MSCa
TCa
TCb
MSCb
MCb
0 5010 20
Switching sequence Type M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 7
MCa MSCa TCa TCb MSCb MCb
MCa
MSCa
TCa
TCb
MSCb
MCb
Switching sequence Type M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 8
MCa MSCa TCa TCb MSCb MCb
MCa
MSCa
TCa
TCb
MSCb
MCb
0 5010 20
Switching sequence Type M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 9
MCa MSCa TCa TCb MSCb MCb
MCa
MSCa
TCa
TCb
MSCb
MCb
Ic
Diverter switch mid-position:
circulating curent Ic determined by step voltage and transition resistor
load current split up in ‚old‘ and „new“ tap
Switching sequence Type M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 10
MCa MSCa TCa TCb MSCb MCb
MCa
MSCa
TCa
TCb
MSCb
MCb
Switching sequence Type M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 11
MCa MSCa TCa TCb MSCb MCb
MCa
MSCa
TCa
TCb
MSCb
MCb
Switching sequence Type M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 12
MCa MSCa TCa TCb MSCb MCb
MCa
MSCa
TCa
TCb
MSCb
MCb
Switching sequence Type M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 13
MCa MSCa TCa TCb MSCb MCb
MCa
MSCa
TCa
TCb
MSCb
MCb
On-Load Tap Changer OILTAP® V III 200 D
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 14
TAP SELECTOR OPERATING
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 15
Motor drive unit
Time in second
Switching element
On-load tap changer
Switching Principle
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 16
Switching sequenc V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 17
Ib
a1
0 10 20 30 40 50
b1a/b
1
b
a
transition contact a1
transition contact b1
main switching contact a/b
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 18
a1
0 10 20 30 40 50
b1a/b
Ib
2
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 19
a1
0 10 20 30 40 50
b1a/b
Ib
2
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 20
a1
0 10 20 30 40 50
b1a/b
Ib
3
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 21
a1
0 10 20 30 40 50
b1a/b
Ib
3
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 22
a1
0 10 20 30 40 50
b1a/b
Ib
3
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 23
a1
0 10 20 30 40 50
b1a/b
Ib
Ib/2
Ib/2
Ic
4
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 24
a1
0 10 20 30 40 50
b1a/b
Ib
5
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 25
a1
0 10 20 30 40 50
b1a/b
Ib
5
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 26
a1
0 10 20 30 40 50
b1a/b
Ib
5
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 27
a1
0 10 20 30 40 50
b1a/b
Ib
6
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 28
a1
0 10 20 30 40 50
b1a/b
Ib
6
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 29
a1
0 10 20 30 40 50
b1a/b
Ib
7
Switching sequence Type V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 30Page 30
Arcs produced during a switching operation
Contact wear
Carbonization of the switching oil
Why Maintenance ?Why Maintenance ?
Switching operation under load in 40 – 50 msSwitching operation under load in 40 – 50 msSwitching operation under load in 40 – 50 msSwitching operation under load in 40 – 50 ms
R
Mechanical stress
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 31
Springs
Braided contact leads
Screw connections
Energy accumulator etc.
Mechanical stressMechanical stressMechanical stressMechanical stress
Why Maintenance ?Why Maintenance ?
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 32Page 32
Tap changer head
Drive shafts
Motor drive unit
Protective relay
Why Maintenance ?Why Maintenance ?
Subject to weatherSubject to weatherSubject to weatherSubject to weather
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 33
The degree of carbonization of the diverter switch oil and the amount of carbon deposits inside the OLTC oil
compartment depend on:
Arcing energy (switched current, etc.)
Number of tap change operations
During maintenance the carbon deposits can easily be removed. Diverter switch type R
with carbon deposits.
Major aspects of Major aspects of maintenancemaintenance criterion: criterion:
Oil carbonisationOil carbonisation
Oil carbonisationOil carbonisation
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 342007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 34
Studies show that moisture content in the sludge ( mixture of oil, carbon and water) deposited on the insulating material surface may be much higher than moisture content of the tap-changer oil.
This effect cannot be determined by taking and analysing oil samples.
Reduction of dielectric properties of OLTC which can only be avoided by regular maintenance..
Diverter switch type R with carbon deposits.
Major aspects of Major aspects of maintenancemaintenance criterion: criterion:
Oil carbonisationOil carbonisation
Oil carbonisationOil carbonisation
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 35Page 35
Number of operationsNumber of operationsNumber of operationsNumber of operations
or
whichever comes first!whichever comes first!
Usually applying for OLTCs in network
application
Usually applying for OLTCs in industrial
application
Maintenance criteriaMaintenance criteria ::
Time in serviceTime in serviceTime in serviceTime in service
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 36Page 36
Survey of number of OLTC operations in various transformer Survey of number of OLTC operations in various transformer applications:applications:
min. mean max
Power range MVA
Voltage range
kV
Current range
A
Number of on-load tap-changer operations.
Power Transformer
Generator
Distribution
Arc furnace
20000
100 - 1300 110 - 765 100 - 2000 500
60 - 525 50 - 1600 2000 7000
50000 200000
Transfomer data
2,5 - 150 20 - 230 50 - 1000 20000
3000 10000
15 - 400
Maintenance criteriaMaintenance criteria ::
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 37Page 37
6 to 7 years
For OLTCs of today‘s manufacturing program used in starpoint application:
i. e. OLTC type M III 600 Y
5 to 6 years
For OLTCs manufactured up until the 70s used in starpoint application:
i. e. OLTC type D III 400 Y
2 years for first,4 years for further
maintenance
For OLTCs in line-end application with Um 245 kV(delta connected windings, autotransformers):
i. e. OLTC types V III delta
3 x M I 1200 – 245 kV
MaintenanceMaintenance intervals are stated in the OLTC’s intervals are stated in the OLTC’s operating instructionsoperating instructions
Maintenance criteriaMaintenance criteria ::
Time in ServiceTime in ServiceTime in ServiceTime in Service
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 38Page 38
Tap changers of same type have been produced for periods of approx. 25 years.
During such a long period each product is subject to an innovation process (new materials, field experience, etc.)
MR’s service policy:
Adaption of easily accessible parts to the latest state of production during OLTC routine maintenance
Applying for measures which increase the operational reliability
Since diverter switch is removed and partially disassembled during maintenance anyway, the updating
measures are comparatively inexpensive
UpdatingUpdating
Maintenance criteriaMaintenance criteria ::
Time in ServiceTime in ServiceTime in ServiceTime in Service
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 39Page 39
Water content*) Dielectric strength**)Neutral-end tap changers 40 ppm 30 kV / 2.5 mmSingle-pole tap changers 30 ppm 40 kV / 2.5 mm
(delta application and autotransformers)
*) measured according to Karl Fischer-Method**) measured according to DIN 57 370 Teil 1 / VDE 0370 Teil 1 / 12.78.
Guideline values for supervision of diverter switch oil were published in CIGRE report 12-13 (1982). These values are value for tap changer oil heated during operation and are stated in
the OLTC operating instructions:
Limit values while OLTC and transformer are in service
Oil valuesOil values
Maintenance criteriaMaintenance criteria ::
Time in ServiceTime in ServiceTime in ServiceTime in Service
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 40Page 40
Difference of contact wear between main switching contacts and transition contacts due to varying transformer load
Maximum permissible difference of contact wear:
Cannot be determined without maintenance
Must not be exceeded during the service of
the OLTC
Contact wearContact wear
Maintenance criteriaMaintenance criteria ::
Number of operationsNumber of operationsNumber of operationsNumber of operations
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 412012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 41Page 41
Contact wear depends onContact wear depends on
Maintenance criteriaMaintenance criteria ::
Number of operationsNumber of operationsNumber of operationsNumber of operations
- wear characteristics of the contact material
- numer of operations
- operating current of the transformer
Evaluation CriteriaEvaluation Criteria
- individual wear
- wear differences
- contact surface
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 42Page 42
Parts replacementParts replacement
Mechanical stress for OLTC components during tap change operation (especially for diverter switch parts).
Precautionary replacement of mechanically stressed components in the course of maintenance
E. g. braided contact leadfor type M: 150,000 operations performed
E. g. energy accumulator springfor type M: 400,000 - 500,000 operations
Maintenance criteriaMaintenance criteria ::
Number of operationsNumber of operationsNumber of operationsNumber of operations
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 43Page 43
Supervision of tap changer oil quality
Taking oil samples from tap changer suction pipeand determination of breakdown voltage
Check of the anti-condensation heater of the motor drive unitPreventing corrosion inside motor drive housing
Check of effectiveness of dehydrating breather of OLTC conservatorAvoiding penetration of water into OLTC conservator and OLTC oil
compartment
This is also valid for transformers which have been shut down or are out
of service
Checks between Inspetctions
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 44Page 44
Precautionary spare parts: cover gaskets (tap changer head cover, protective relay)
Spare parts which depend on the number of operations: Energy accumulator springs, flexible
leads, contact carrier etc.
Spare parts which are subject to wear: arcing
contacts, drive shaft coupling bolts etc.
Spare parts to up-date the tap-changer to the lates state of manufacture
Spare parts requirement during routine Spare parts requirement during routine maintenancemaintenance
Spare part replacementSpare part replacement
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 45Page 45
The MR service also applies to tap-changers like:
On-load tap changer manufactured by Siemens,
AEG & Trafo Union
On-load tap changers manufactured under the MR licence (e.g. Toshiba, Mitsubishi etc.)
MR TECHNICAL SERVICEMR TECHNICAL SERVICE
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 46
Summary
High operating safety
A routine inspection of the tap changer can be completed by qualified and experienced personnel within few hours
The life time of the arcing contact used in network application exceed the life of the transformer in the majority of cases
Transition resistance values shows no change even at the highest switching requency
2009 CS5O© Maschinenfabrik Reinhausen GmbH
Page 47Page 472012 CS5O Boris Wende
Maintenance performance
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 48Page 48
General Notes on the Preparation of an On-Load Tap-Changer Maintenance by MR
OLTC-type ** A B C250 C350 D (D Δ) E F G H KM / MS(MΔ)
T / R V VV
Oil quantity (l)* 30 100 150 250200
(300)220 320 900 355 650
190(280)
210 220 325
Weight of the diverter sw itch insert (kg)
20 60 100 150100
(120) 150 250 500 80 35080
(90) 120 60 50
Max. lif ting height (mm) 1900 2250 2500 2400
1500(2150) 1850 1750 2300 2150 1900
1400(1870) 1650 1950 2200
Table: Oil quantities, weights, lifting height
* Transformer oil in accordance with IEC 60296 und IEC 60422 with a dielectric strenght of at least 50 kV/2,5mm (measured as per IEC 60156)
** Information on on-load tap-changers made by Siemens, AEG and Trafo-Uniion is available on request
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 49
• Switching OLTC into adjustment position
• Draining off tap changer oil
• Removal of horizontal drive shaft
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
Page 49 of 24
2009 CS5O© Maschinenfabrik Reinhausen GmbH
Page 50Page 502012 CS5O Boris Wende
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
Page 50 of 24
• Removal of OLTC cover
• Withdrawal of diverter switch insert
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 512012 CS5O Boris Wende
Cleaning of OLTC oil conservator and oil compartment
Visual check of insulating material (oil compartment, suction pipe and indicating rod) and of sliding contacts
Check of pressure tightness of diverter switch oil compartment
WARNING: To clean only use pure transformer oil.
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 52
Removal of diverter switch supporting cylinderCleaning and visual inspection of supporting cylinder and insulating drive shaft
View inside diverter switch supporting cylinder before cleaning
Diverter switch insulating drive shaft
before cleaning
2012 CS5O Boris Wende
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 53
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
Pawl in locked position Pawl in unlocked position
• Unlocking the pawl of the diverter switch and bringing the diverter switch in mid-position for reduction of contact pressure (see above)
• Removal of diverter switch contact shells in diverter switch mid-position
Page 53 of 24
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 54
Removal of contact shells Undo the fixing screws of the contact shells
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 55
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
Diverter switch contact shell
• Removal of diverter switch contact shells
• Cleaning and visual inspection of contact shells
• Measurement of contact wear on fixed contacts
• Check of spark gaps
• Measurement of transition resistors
• If necessary, replacement of:Resistor connection leadsFixed contactsCurrent strips
Page 55 of 24
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 562012 CS5O Boris Wende
Measurement of transition resistors Measurement of contact wear
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 572012 CS5O Boris Wende
Removal of diverter switch contact shells in diverter switch
mid-position
Cleaning and visual inspection of diverter switch (overall
condition)
Measurement of contact wear on movable contacts
If necessary, replacement of: - Braided contact leads, - Contact carriers, - Contacts, - Arcing chambers - Energy accumulatorMovable contact system of diverter switch after
removal of contact shells
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 58
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 59
Removal of stationary and movable contacts
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 60
Removal of braided leads
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 612012 CS5O Boris Wende
Re-installation of arcing chambers
Re-installation of contact shells
Re-installation of insulating drive shaft and supporting cylinder
Measurement of transition resistors as a countercheck (corresponding contacts must be open)
Manual test operations (pawl must be locked in!)
Final flushing with clean oil
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 62
Fill new oil into the diverter switch oil compartmentVent the tap changer head through the bleeder screwVent the suction pipe
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 63
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
Opening and cleaning OLTC protective relay
Visual check
Installation of new gasket and closing cover again
Test of protective relay
Page 63 of 24
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 64
• Installation of horizontal drive shaft
• Check symmetry of coupling between motor drive and OLTC
• Trial operations across the regulating range by means of hand crank operation (comparison of position indicated on OLTC and motor drive)
Page 64 of 24
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 65
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
Check of overall condition and function of motor drive:
• safety switch
• limit switches
• step-by-step function
• anti-condensation heater etc.
Page 65 of 24
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 66
OILTAP® MMaintenance of On-load Tap-changer OILTAP® M
• Writing maintenance report with all relevant data
• Keeping file or a databank with maintenance results (documentation)
Page 66 of 24
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 67
Reaching adjustment position by turning hand crank clockwise
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
• Switching OLTC into adjustment position
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 68
• Draining off tap changer oil
• Removal of horizontal drive shaft
• Remove OLTC head cover
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 69
Removal of OLTC gear and suction pipe
Check of marks for re-installation of OLTC insert
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 702012 CS5O Boris Wende
Careful withdrawal of OLTC insert by means of MR lifting device or crane and chain hoist
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 71
Cleaning of oil compartment
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 722012 CS5O Boris Wende
Placing OLTC insert on a working table in horizontal position
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 73
Removal of the switching elements
Removal of the inner screening rings
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 74
Cleaning switching tube of OLTC insert inside and outside by means of transformer oil and brush
Cleaning of switching elements
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 75
Measurement of the transition resistors
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 76
Determination of the contact wear
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 77
Checking the spring movement of the contact rollers
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 782012 CS5O Boris Wende
Preparation of OLTC insert for re-installation
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 79
Re-installation of suction pipe
Re-installation of the cleaned gear unit
Trial operations and check of limit position blocking
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 802012 CS5O Boris Wende
Opening and cleaning OLTC protective relayVisual checkInstallation of new gasket and closing cover again Test of Protective relay
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 812012 CS5O Boris Wende
Check of overall condition and
function of motor drive:
safety switch limit switches step-by-step function anti condensation heater etc.
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 822012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 82
• Installation of horizontal drive shaft
• Check symmetry of coupling between motor drive and OLTC
• Trial operations across the regulating range by means of hand crank operation (comparison of position indicated on OLTC and motor drive)
Page 82 of 24
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 832012 CS5O Boris Wende
Writing inspection report with all relevant data
Keeping file or a databank with inspection results (documentation)
OILTAP® VMaintenance of On-load Tap-changer OILTAP® V
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 842012 CS5O Boris Wende Page 84
Practical example for the preservation and evaluation of the condition of the equipment
Online oil filtration with Oil Filter unit
Effects:
- Removal of carbon particles from the tap-changer oil
- Keeping the water content to a minimum
Active measure for improving oil quality
Benefits:
- Improving operational reliability of OLTC and transformer
- Extension of maintenance intervals
- Reduction of maintenance cost
- No need for cleaning during maintenance
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 85
Use of maintenance-free dehydrating breather for OLTC and transformer conservator
Effects:
- No changing of Silica-gel
- Always the same dry condition of the air into the transformer
Active measure for good working condition of the breather
6. Measures for Equipment Preservation
Date: 26.03.20072007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 862012 CS5O Boris Wende Page 86
Practical example for the preservation and evaluation of the condition of the equipment
Use of maintenance-free equipment
Use of VACUTAP® OLTCs for new transformers
Preferable strategy for OLTCs and transformers
replaced by
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 872012 CS5O Boris Wende
Advantages of the vacuum technology
Vacuum technologycontact wear reduced to a minimumNo arcing in the oilNo oil carbonization
Conventional technologyWear of single contactsContact wear differenceOil carbonization
VACUTAP®: Extension of the maintenance interval up to 300.000 operations and no time based maintenance
Vacuum interrupter
Transition contactMain switching contact
Transition contact
Switching elementVACUTAP®VV
Switching element OILTAP®V
2007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
Page 882012 CS5O Boris Wende
Innovation VACUTAP® Life-Cycle-Cost Consideration
OILTAP ®
Significant savings in maintenance costs
Benefits
longer availability of the transformer
simplified maintenance logistics
protection of environment and natural resources due to reduction of oil changes
only familiar checks required
Considerably reduced operating costs
Maintenance-free up to 300.000 operations with VACUTAP® V V and VR
No time-based maintenance
Are you still using conventional on-load tap-changer technology?
Maintenance Intervals
2012 CS5O Boris Wende© Maschinenfabrik Reinhausen GmbH
Page 90
Retrofit - Solution
OILTAP®M VACUTAP®VM
91
Perfect Retrofit-Solution
VACUTAP® VM © Copyright MR Maschinenfabrik Reinhausen GmbH
Compatible with OILTAP® M / MS and other on-load tap-changers based on OILTAP® M
No modification work on the oil compartment required
92
Retrofittable VACUTAP® VM Diverter Switch Insert
100% connection-compatible with OILTAP® M
• Licensed tap-changers can also be upgraded
• Also suitable for non-authorized models similar to OILTAP-M
Benefits of VACUTAP®
• Lifetime of diverter switch insert: 1.2 million tap-change operations
• 300,000 tap-change operations without any maintenance
VACUTAP® VM © Copyright MR Maschinenfabrik Reinhausen GmbH
93© Copyright MR Maschinenfabrik Reinhausen GmbH
No Interaction between Arc and Oil
Conventional technology
Switching arc under oil
Oil: insulating, cooling, lubricating and arc quenching
VACUTAP® technology
Switching arc in vacuum
Oil: just insulating, cooling and lubricating
VACUTAP® VM © Copyright MR Maschinenfabrik Reinhausen GmbH
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Extended Oil Service Life
Conventional technology
Oil ageing due to carbon particles resulting from arc quenching
Oil filter to be exchanged regularly
VACUTAP® technology
No break-down arc in tap-changer oil
No oil filter unit necessary
VACUTAP® VM © Copyright MR Maschinenfabrik Reinhausen GmbH
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Marginal Contact Wear
Conventional technology
Contact wear
Contact life: 200,000 to 500,000 switching operations
VACUTAP® technology
Rate of contact wear is more than one decade lower compared with copper-tungsten contacts
Contact life: 600,000 switching operations
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Less Maintenance
Conventional technology
Maintenance each 40,000 to 100,000 switching operations, depending on the operation mode
Additional time-based criteria
VACUTAP® technology
Maintenance each 300,000 switching operations, therefore maintenance-free in most network applications
Enhanced transformer availability
No time- or current-based criteria
Less spare parts, simplified logistics
VACUTAP® VM © Copyright MR Maschinenfabrik Reinhausen GmbH
Maintenance intervals Maintenance intervalst t
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OILTAP® VACUTAP®
55 %
100 %
Electric Arc Furnace (EAF) Application
High system availability and reliability
- Maintenance interval: 300,000 switching operations without time- or current-based criteria
- Significantly longer oil service life and contact life
- Reduced downtime of the transformer due to faster maintenance
Protection class IP 66 for TAPMOTION® ED suited for aggressive environment
Significant reduction of maintenance costs
- Example: 200,000 switching operations per year, 20 years transformer service life, operation in central Europe
- 45 % cost reduction for on-load tap-changer maintenance, spare parts and oil filters over the transformer service life
VACUTAP® VM © Copyright MR Maschinenfabrik Reinhausen GmbH
Maintenance costs
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The VACUTAP® VM diverter switch insert is
retrofittable, which means longer maintenance
intervals and maximum cost-effectiveness
The new VACUTAP®
Arc-Control System™
extinguishes the commutating arc with
absolute reliability
The new VACUTAP® Step Protection System™
effectively protects the diverter switch against tap short circuits in the event of overvoltage on the grid
The Interrupter Exchange Module
shortens production downtimes for maintenance
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2 3
Unique. Better For 4 Reasons.
Date: 26.03.20072007 Gerhard Peißer© Maschinenfabrik Reinhausen GmbH
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