TOGA PRESENTATION REVIEW OF CASE STUDIES. Paul Boman,

Transcription

1 TOGA PRESENTATION REVIEW OF CASE STUDIES Paul Boman, October 8, 2014

2 HSB s TOGA History TOGA Transformer Oil Gas Analyst Registered trademark of Hartford Steam Boiler Inspection and Insurance Formed mid-1980 s Insulating fluid Expanded to include other fluids like; Lube oil Hydraulic fluid Heat transfer fluid for Pulp and Paper Gas like Landfill or Methane Produced from Digesters Internet based The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/2014 2

3 Transformer Failure Rates Translates into Equipment Numbers 5 to 30 of 1,000 power transformers fail IEEE Gold Book Survey Varies greatly by region and company 5.8 of 1,000 (.58%) HSB Insured transformers fail Based on claims data Estimated 100,000 population pp 2014 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/2014 3

4 TOGA Failure Rates Failure rate over a 4-year period 1.5 of 1,000 (.15%)TOGA Transformers Fail All causes 8 of 100,000 (.008%)TOGA Transformers Fail TOGA effective causes like Overheating Thermal Arcing 2014 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/2014 4

5 Catastrophic Failure Rates CIGRÉ Brochure 537 from A2.33 Study Based on Canadian Population of Transformers Insulating Fluid typically mineral oil 70% to 80% of catastrophic failures due to bushings Serious Failures at ½% to 1.4% Fire estimated at 5% to 15% of all Serious Failures 2014 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/2014 5

6 Successful Analytic Programs Have Consistent sample extraction Repeatable laboratory analysis Accurate result evaluation Follow-up of results 2014 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/2014 6

7 Consistent Sample Method Sample Procedures Check for tank vacuum DGA & moisture from syringe Condition of Equipment Flush bottle & syringe Screen tests from bottle Equipment On-line Cleanliness Cleanliness Timely processing Atmospheric contamination 2014 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/2014 7

8 Quality Control Programs 2014 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/2014 8

9 Dissolved Gas Analysis Models Symbol Fault Duval Examples PD D1 D2 T1 T2 Partial discharges Discharges of low energy Discharges of the cold plasma ( corona ) type in gas bubbles or voids, with the possible formation of X-wax in paper. Partial discharges of the sparking type, inducing pinholes, carbonized punctures in paper. Low energy arcing inducing carbonized perforation or surface tracking of paper, or the formation of carbon particles in oil. Discharges of Discharges in paper or oil, with power followthrough, g, resulting in extensive damage to paper pp high energy or large formation of carbon particles in oil, metal fusion, tripping of the equipment and gas alarms. Thermal fault, Evidenced by paper turning brownish ( >200 C T <300 C ) or carbonized ( >300 C) ). Thermal fault, 300 <T<700 C Carbonization of paper, formation of carbon particles in oil. T3 Thermal fault, Extensive formation of carbon particles in oil, >700 C metal coloration ( 800 C ) or metal fusion ( >1000 C ) PD T T2 23 % CH 4 % C 2 H D1 D2 DT T % C 2 H The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/2014 9

10 Dissolved Gas Analysis Models IEC Ratio Diagnostics Case Term 1 Term 2 Term 3 Partial discharge (PD) =C 2 H 2 / C 2 H 4 = CH 4 / H 2 = C 2 H 4 / C 2 H 6 Nonsignificant <0.1 < 0.2 (NS) Discharges of low energy (D1) > > 1 Discharges of high energy (D2) 0.6 to > 2 Thermal fault, t <300 C (T1) NS >1 but NS < 1 Thermal fault, 300 C < t < 700 C (T2) < 0.1 >1 1 4 Thermal fault, t > 700 C (T3) < 0.2 >1 > The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/

11 Case Study: LIGHTNING STRIKE De-energized Tap Changer (DETC) Lead DGA (PPM) 11-Jan-01 1-Feb Feb Mar Jul Distribution Transformer base rating of 12 MVA, 69 kv to 13.8 kv Days between The transformer tripped off-line from Samples protective relays during a lightning storm. Electrical testing did not Hydrogen indicated a problem. Oxygen 2, ,290 1, ,553 5,276 Nitrogen 76,042 82,848 73,290 64,447 90,279 Methane Carbon Monoxide Carbon Dioxide Ethylene Ethane Acetylene The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/

12 . PA Core Problem on a New Transformer Dissolved Gas Analysis Hydrogen 6,277 Oxygen 1,822 Nitrogen 6,711 02/11/2012 Roger's Ratios Method 02/11/2012 R1 (CH 4 /H 2 ) R2 (C 2 H 6 /CH 4 ) 0.83 R3 (C 2 H 4 /C 2 H 6 ) 5.36 R4 (C 2 H 2 /C 2 H 4 ) 0.01 Methane 111,021 Carbon Monoxide Carbon Dioxide Diagnostic Other Important t Ratios Closest Fit; core ground O 2 / ( O 2 + N 2 ) 0.21 CO 2 /CO - Duval Triangle Method 02/11/2012 Ethylene 492,176 Ethane 91,767 % CH4 18.3% %C2H4 81.2% %C2H2 0.5% Acetylene 2,993 Diagnostic Code T2 Region, 2014 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/

13 Times to Sample New Fluid (Baseline Sample) Full Sample Prior to Energized Establish Trend Initial Sample Sequence Monitors Equipment when Energized 24-hour, 48-hour and 72-hour DGA only Samples 1 week DGA, 1 month DGA, 3 month DGA, 6 month DGA Routine Sample Schedule Unit Transformer - 6 month DGA, annual physical and dissolved moisture Other Transformers - annual ldga, physical and ddissolved dmoisture testst 2014 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/

14 Case Study: High Resistance Connection Low Voltage Compression Connection DGA (PPM) Sample Date 20-May Jun-08 2-Jul-08 7-Jul Jul Aug-08 Days between Samples 21 OEM Insp Hydrogen Oxygen 2,414 2, , ,004 Nitrogen 101,590 58, ,954 51,468 86,139 Methane CO CO Ethylene 473 1, Ethane Acetylene The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/

15 Case Study: High Resistance Connection Low Voltage Compression Connection DGA Rate of change (PPM / Day) Sample Date 17-Jul Aug Sep Oct Oct-12 Hydrogen Oxygen Nitrogen Methane Carbon Monoxide Carbon Dioxide Ethylene Ethane Acetylene The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/

16 Natural Ester Case Study High Resistance Shield Connection Sample Data (PPM) Sample Date 18 JAN AUG JUL AUG 2007 Days between Sample Hydrogen (H2) Oxygen (O2) 1, ,539 Nitrogen (N2) 62,708 60,086 42,571 50,300 Methane (CH4) CO CO Ethylene (C2H4) Ethane (C2H6) Acetylene (C2H2) The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/

17 Natural Ester Case Study High Resistance Shield Connection Duval Triangle Ratios Ratios 31-Jul Aug-07 % CH 4 0.6% 16.8% %C 2 H % 15.0% %C 2 H % 66.6% Diagnostic Code Discharges of Low Discharges of Energy Low Energy D1 D The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/

18 Natural Ester Case Study Transformer Winding Shield Shield Ground Conductor 2014 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/

19 Natural Ester Case Study DGA Results for Bank of Single Phase 238 kv Transformers (PPM ) Unit Sample Date T1 pre- repair 18-Jan- 06 T2 31-Jul- 07 T3 31-Julspare 07 T4 24-Oct- 07 T1 post 14-Seprepair 10 Hydrogen Oxygen Nitrogen Methane CO Carbon Dioxide Ethylene Ethane Acetylene , , ,901 47, ,353 55, , The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/

20 . High Voltage Loose Connection Dissolved Gas Analysis Hydrogen 10,097 Oxygen 6,695 Nitrogen 62,130 Methane 1,083 03/08/2012 Roger's Ratios Method 03/08/2012 R1 (CH 4 /H 2 ) 0.11 R2 (C 2 H 6 /CH 4 ) 0.32 R3 (C 2 H 4 /C 2 H 6 ) 1.56 R4 (C 2 H 2 /C 2 H 4 ) 0.02 Diagnostic Closest Fit; Conductor Overheating Carbon Monoxide 541 Carbon Dioxide 4,656 Ethylene 533 Ethane 342 Acetylene 11 Other Important t Ratios O 2 / ( O 2 + N 2 ) 0.10 CO 2 /CO 8.61 Duval Triangle Method 03/08/2012 % CH % %C 2 H % %C 2 H 2 0.7% Diagnostic Code T2 Region, 2014 The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/

21 High Resistance Connection De-energized Tap Changer (DETC) Contact DGA Rates of Change (PPM/Day) Sample Date 11/22/02 07/31/02 01/14/02 11/21/01 Hydrogen Methane (2.55) 4.09 Carbon Monoxide Carbon Dioxide Ethylene Ethane Acetylene The Hartford Steam Boiler Inspection and Insurance Company. All rights reserved. 10/3/

22 THANK YOU VERY MUCH FOR YOUR ATTENTION Paul Boman, October 8, 2014