Si-COAT® 570™ Reliability &...
Transcript of Si-COAT® 570™ Reliability &...
Si-COAT® 570™RTV Silicone HVIC
Reliability & Beyond
Seminar Presentation
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
Overview
• Background & industry pressures₋ Early validation of Si-COAT HVIC
• The science of Si-COAT
• Q&A
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
Si-COAT HVIC : The Background
• A need for a robust insulator coating₋ Excellent adhesion required
₋ Elimination of water washing required
• Si-COAT Formulated for:
₋ Superior adhesion
₋ Very smooth surface finish
₋ Extremely long life
• Two very surprising advantages discovered!
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
Si-COAT : The Advantages
• One-part RTV (ready-to-use)
• Superior adhesion
• Smooth surface finish
• Rich LMWS concentration
• Low surface free energy₋ Very high hydrophobicity
• Maintenance free
• Near total suppression of leakage current
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
A Thorn in Reliability’s Side…
Insulator contamination : a long posed nuisance
• Water washing
₋ Short-term solution
• Greasing
₋ Short-term solution
• Composite insulators
₋ Questionable reliability
• RTV Silicone Coatings
₋ Reliable performance
₋ Leverages mechanical integrity of ceramics
₋ A cure for ailing composites
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
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Year 0 Year 2 Year 4 Year 6 Year 8 Year 10
Cum
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tive E
xpen
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Water
Grease
Si-COAT
Si-COAT versus Water & Grease
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
Si-COAT : a Remarkable Effect
Leakage current nearly eradicatedLABORATORY
• Zittau University (Germany) Testing₋ IEC 62217 Salt Fog Test; 1,000 hours
• KEMA (Netherlands) Testing₋ IEC 61109 Salt Fog Test; 5,000 hours
FIELD
• US Dept. of Energy₋ > 99% suppression over 10 years
• PPC Greece₋ > 99.9% suppression in IEC Class IV contamination zone
• Kinectrics Research₋ 20 kW/km recoverable!
• Koeberg (KIPTS) Testing
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
IEC 62217 : 1,000 hr Si-COAT Result
Data : Prof R. Bärsch, HV Lab, Zittau University of Applied Sciences
Test Parameters• Medium voltage porcelain
- 700 mm creepage
- 60 mm core diameter
- 122 mm shed diameter
- 355 mm dry arc resistance
• 20.3 kV ; 0.29 kV/cm
• 6.7 mS/cm fog conductivity (ref. 50 mS/cm for sea water)
Observation• Max leakage current of
<0.1 mA
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
IEC 61109 : Si-COAT Shines
Final Test Report, KEMA Laboratories, The Netherlands, 2004
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
Si-COAT ® HVIC Thermal Imagingin Rural Italy
Thermal imaging via infrared cameras measures the rise in temperature, above ambient, of various structures.
Since leakage current generates heat, thermal imaging is an ideal and cost-efficient tool to measure approximate levels of leakage current.
Thermal imaging by infrared cameras of insulators coated withSi-COAT and those left uncoated reveal that uncoated insulators undergo an appreciable rise in temperature.
Each Celsius degree rise in temperature above ambient roughly correlates to 2 mA of leakage current.
The approximate 9°C temperature rise of uncoated sections in this photograph indicate roughly 18 mA of leakage current on uncoated insulators.
Coated insulators show no rise in temperature, translating to an effective zero level of leakage current.
Si-COAT HVIC coated insulator
(at ambient temp.)
Uncoated insulators
(at elevated temp.)
Photo courtesy of Terna of the Enel Group, Italy
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
US Dept. of Energy Experience
Columbia Generating Station
• 1,150 MW Nuclear Plant
• Owned & operated by Energy Northwest
• Sole customer is Bonneville Power Administration (US Dept. of Energy)
• East side of Washington State₋ Seemingly unlikely place
for insulator contamination
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
(US DoE) : Plant Configuration
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
(US DoE) : Plant Configuration
Transformer yard on north side of station
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
• Prevailing winds from south
• Plume & contaminants carried to transformer yard
northsouth
(US DoE) : Contamination Issues
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
(US DoE) : Contamination Issues
Condensed plume migrating north to transformer yard
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
(US DoE) : Contamination Issues
Typical contamination buildup
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
(US DoE) : Contamination Issues
• Cooling water drawn from Columbia River
• Contamination sources₋ Natural river contaminants
₋ Buffer chemicals
• Contaminants in circulation water₋ Anions:
sulphate, bicarbonate, silica, chloride, orthophosphate, fluoride
₋ Cations:calcium, magnesium, sodium, ammonia, copper, zinc, iron
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
(US DoE) : Failure in Reliability
Flashover #1:
• 17h14, 30-January-89
• Plume condensed in cold
• Corrective action: annual water washing
Flashover #2:
• 10h10, 10-December-90
• Corrective action: find the correct solution
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
I. Cleaning• Off-line cleaning• Hot line washing• Installed insulator washers
II. Monitoring• Insulator leakage current
monitoring• Weekly measurement of ESDD• Meteorological monitoring• RF/Ultrasonic
III. Contamination Source Reduction• Transformer Yard cover• Transformer Yard wind
deflectors• Drift eliminators• Cooling tower plume reduction• Hot air ducted into transformer
yard
IV. Insulator Modifications• Fog type insulators• Non-ceramic insulators• Resistance graded insulators• Creepage extenders• Silicone grease• Si-COAT RTV Silicone HVIC
(US DoE) : Reliability Investigations
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
(US DoE) : Si-COAT HVIC Testing
• Si-COAT under test from 1989
• Intensive testing initiated late 1991
• Principal property was to improve hydrophobicity (prevent water filming)
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
Fog Chamber Tests Round 1 (31-Dec-92)
• Coated & uncoated insulators first contaminated for 3 months under plume
• ESDD up to 0.111 mg/cm2, area weighted avg.
Trial #1 Trial #2
Minutes to Flashover
Per Unit Rated Voltage
Minutes to Flashover
Per Unit Rated Voltage
Bare 20 2.0 55 2.0
Other RTV 94 2.0 116 2.0
Si-COAT RTV >120 2.6 >120 2.9
(US DoE) : Si-COAT HVIC Testing
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
Fog Chamber Tests Round 2 (05-May-93)
• 31.5 in station post insulators
• Exposure:₋ 20 days tower mist and 26 lbs dust
₋ 5 days mist and heat cyclingFlashover Voltage
Per Unit Rated Voltage
Bare 117 kV 1.52
Company 1 RTV 131 kV 1.70
Company 2 RTV 227 kV 2.94
Silicone Grease A 240 kV 3.11
CSL-880 Grease 250 kV 3.25
Si-COAT RTV 251 kV 3.26
(US DoE) : Si-COAT HVIC Testing
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
(US DoE) : Conclusions
• Si-COAT provided superior results for reducing risk and preventing flashover
• With the concurrence of US DoE, Energy Northwest determined Si-COAT (CSL) RTV HVIC offered best prospects for preventing future service interruptions
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
(US DoE) : Results
• Si-COAT virtually eliminated leakage current
Maximum Broad-Band Leakage Current
Uncoated Insulator
Si-COAT RTV HVIC Coated Insulator
18-Dec-93 50 mA< 0.25 mA(> 99.5%
suppression)
Apr-94 100 mA< 0.25 mA(> 99.8%
suppression)
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
(US DoE) : Results
• US DoE Internal Report 03-Jun-94₋ Si-COAT avoided at least 6 forced outages in first
year alone
• Leakage current, hydrophobicity and resistance testing indicated good condition after 10 years of service₋ Recoat at 10 years as insurance
• Few visible signs of degradation
Si-COAT® 570™RTV Silicone HVIC
The Science
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
electrons LEAKalong a dirty insulator
particlesof dirt
Insulators conditions are not Perfect
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
How Does Si-COAT Work?
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Si-COAT LMWS Encapsulates Dirt
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Water Can’t Combine with Dirt
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Si-COAT has Most LMWS
Si-COAT Other RTV HVIC
Relative bulk LMWS concentrations as revealed by X-ray mapping technique
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
How To Avoid Damage to Silicone!
this area getsWARM & DRY
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• Dry band arcing₋ Very high
temperatures
₋ Can damage unprotected coating
How To Avoid Damage to Silicone!
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
Dry Band Arcing Damage is Beaten
• ATH: Alumina Trihydrate
• Dry band arcing activates ATH
• ATH absorbs the energy of dry band arcing
• Coating is protected and undamaged
• Surface of ATH particle is most critical
₋ The greater the surface area of the ATH, the more protection that is offered
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
Smaller ATH = More Surface Area
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Very Small ATH Restricts LMWS
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Larger ATH Promotes LMWS Flow
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13 microns : Optimum ATH Size
• The basis of CSL’s patent for Si-COAT HVIC is the 13 micron Optimum ATH Particle Size
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
Developing Ultra-Hydrophobicity
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Ultra-Hydrophobicity Explained
• Ultra-Hydrophobicity is also known as “The Lotus Leaf Effect”
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
Ultra-Hydrophobicity Explained
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Ultra-Hydrophobicity, Turkey (2 years)
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Ultra-Hydrophobicity, Turkey (2 years)
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
Ultra-Hydrophobicity, Turkey (2 years)
© 2012 CSL Silicones Inc. All trademarks registered. All rights reserved.
In Conclusion
1. The Si-COAT patented technology proposes three levels of value:
• Maintenance reduction
• Reliability improvement
• Economic/Environmental benefits
2. Si-COAT virtually eliminates leakage current for the long term
3. Therefore, significant reduction in expenses and losses due to planned/unplanned outages
4. Investment in Si-COAT veryquickly recovered
Si-COAT® 570™RTV Silicone HVIC
Q&A Session
Seminar Presentation