IEEE Std. C57.100

IEEE Standard Test Procedure for Thermal Evaluation of Liquid-Immersed Distribution and Power Transformers

11:00 am to 12:15 amMonday, 23 October 2006

St. Laurent RoomDelta Centre-Ville Hotel

Montréal, Québec Canada

Agenda

1. Introduction and Rosters2. Approval of Minutes from 20 March 2006 Meeting3. Patent Disclosure (if applicable)4. Discussion of DuPont – Weidmann Test of Power

Transformer Model 5. Discussion regarding work and how to implement

into our document. 6. Open items from past meetings

Discussion of DuPont - WeidmannTest of Power Transformer Model

• Comparison Aging Curves to Historical Curves (C57.91-1981 and C57.92-1981)

• Comparison of Model Testing to Sealed Tube Tests

• Comparison of DP Life Curves to 50% Tensile Life Curves

• Comparison of Upgraded to Non-Upgraded Paper• Oil Quality vs. Life Testing• Work in Progress/Future Work

DuPont- Weidmann Test

• Review of purpose of test from last meeting• Findings to Date• Next Steps in Testing• Evaluate test methodology to determine use

as an IEEE method.

DuPont – Weidmann TestPurpose – Utilize the IEC 62332 methodology to evaluate thermally upgraded kraft – comparing results to historical data presented in C57.100.

Products to test: Range of kraft papers from 0% Nitrogen (non-upgraded paper) to 2.74% Nitrogen content (Insuldur) [0, 1.0, 1.6, 2.48 and 2.74% N2]

Will evaluate the conductor insulation using mechanical testing (tensile strength) and DP. Will evaluate spacer material using mechanical testing (compressibility) and DP. Will evaluate bulkoil insulation using mechanical testing (tensile strength) and DP. Will evaluate the oil after aging with DGA, moisture, furans, etc.

DuPont – Weidmann Test

Compare data from this model to other aging curves (distribution transformers, sealed tube test). Later, Compare existing insulation system with proposed system to determine allowable hottest spot temperature.

DuPont – Weidmann Test

Progress Since Last Meeting

• Life Curves for non-upgraded paper nearing completion with data past 50% tensile retention for most temperatures

• Life Curve for one of the upgraded papers nearing completion

• Analysis of DP, Furans, Initial Oil Quality testing • Prototype test of moisturizing conducted.• Modifications/upgrades to test cells identified.

Non-Upgraded Temperature Plots140C Plot

y = -1.929115E-09x3 + 1.256510E-05x2 - 3.217868E-02x + 1.000000E+02

20.00

40.00

60.00

80.00

100.00

0 1000 2000 3000 4000

148C Ploty = -3.66980E-09x3 + 2.72147E-05x2 - 5.84560E-02x +

1.00000E+02

20.00

40.00

60.00

80.00

100.00

0 1000 2000 3000 4000 5000

156C Ploty = -7.58079E-09x3 + 4.42508E-05x2 - 7.65712E-02x +

1.00000E+02

0.0020.0040.0060.0080.00

100.00

0 1000 2000 3000 4000 5000

164C Plot

y = -6.66887E-08x3 + 1.84167E-04x2 - 1.63725E-01x + 1.00000E+02

20.00

40.00

60.00

80.00

100.00

0 500 1000 1500 2000

172C Ploty = -2.11865E-07x3 + 4.02724E-04x2 - 2.68155E-01x +

1.00000E+02

20.00

40.00

60.00

80.00

100.00

0 200 400 600 800 1000

180C Ploty = -2.20338E-06x3 + 2.16653E-03x2 - 6.49023E-01x +

1.00000E+02

0.0020.0040.0060.0080.00

100.00

0 200 400 600

180 172 164 156 148 140

Initial Aging vs. Historic Life Curves

Per Unit Plot – Three paper Types

Limited data points for 1.60% N2. Still, life is seen between other two curves

3 Paper Arrhenius

0

1

2

3

4

5

6

0.00205 0.0021 0.00215 0.0022 0.00225 0.0023 0.00235 0.0024 0.00245

1/T

Log

Life

2.74%N2 0%N2 1.60%N2

Comparison of New Method to Sealed Tube

Conducting sealed tube tests with the same cell configuration (in an oven) – all materials at 148C. Historical expectation would be for 264 hours life. Historical aging, however likely involved sealed with air and/or moisture content. Predicted life for the sealed tube is 888 hours with our test set up and oil processing.

Non-upgraded Kraft Aging

y = -6.471933E-08x3 + 1.455028E-04x2 - 1.344885E-01x + 1.000000E+02R2 = 9.884772E-01

0.0020.0040.0060.0080.00

100.00

0 1000 2000 3000 4000 5000

Hours at 148C

Perc

ent T

ensi

le

Rete

ntio

n

Model Testing Sealed Tube Testing

Sealed Tubes

Same materials as in Dual temperature cells, at ½ the size, due to reduced amount of oil in the cell to allow for expansion due to the high temperatures of the oil. Insulation pictured is just the conductor loop.

Sealed Tube ComparisonAcid Number vs. Aging Method

0.000.050.100.150.200.25

0 1000 2000 3000 4000 5000

Hours at 148C

Aci

d N

umbe

r

Model Testing Sealed Tube Testing

Moisture Content of Oil vs. Aging Method

020406080

100

0 1000 2000 3000 4000 5000

Hours at 148C

ppm

Moi

stur

e

Model Testing Sealed Tube Testing

Comparing test results at 148C, the model test maintains better oil quality, allowing an evaluation of the solid insulation separately.

DP vs. Tensile – Paper Samples

DP of un-aged non-upgraded paper – 1224DP of 2.74% N2 paper - 1129

DP Plots140 DP vs. Aging Time

y = -0.09822x + 684.77114R2 = 0.84626

0.0200.0400.0600.0800.0

1000.0

0 1000 2000 3000 4000

Aging Time - hours

DP

Valu

e148 DP vs. Aging

y = -0.06052x + 588.57989R2 = 0.78196

0.0

500.0

1000.0

0 1000 2000 3000 4000 5000

Aging Time in Hours

DP

Valu

e

156 DP vs. Agingy = -2.22198E-07x3 + 1.25302E-03x2 - 1.99078E+00x +

1.22400E+03R2 = 8.04791E-01

0.0

500.0

1000.0

1500.0

0 1000 2000 3000 4000

Aging Time in Hours

DP

Valu

e

164 DP vs. Agingy = -1.27157E-06x3 + 3.75188E-03x2 - 3.40509E+00x +

1.22400E+03R2 = 7.62215E-01

0.0

500.0

1000.0

1500.0

0 500 1000 1500 2000

Aging Time in Hours

DP

Valu

e172 DP vs. Aging

y = -6.97560E-06x3 + 1.18769E-02x2 - 6.26896E+00x + 1.22400E+03

R2 = 9.63037E-01

0.0

500.0

1000.0

1500.0

0 200 400 600 800 1000

Aging Time

DP

Valu

e

180 DP vs. Agingy = -6.25532E-05x3 + 5.23884E-02x2 - 1.32695E+01x +

1.22400E+03R2 = 9.75089E-01

0.0

500.0

1000.0

1500.0

0 100 200 300 400 500

Aging Time

DP

Valu

e

DP Arrhenius – non-upgraded

DP Plots by Paper TypeDP Arrhenius vs. Nitrogen Content

y = 6941.1x - 12.474R2 = 0.924

y = 7815.9x - 14.908R2 = 0.8776

0

1

2

3

4

5

0.00205 0.0021 0.00215 0.0022 0.00225 0.0023 0.00235 0.0024 0.00245

1/T

Log

Life

2.74%N2 0% N2

Arrhenius Plots - 2.74%N2

Oil QualitySample oil with syringe for DGA data and then sample oil after cool-down for oil properties. Oil samples to date have all been very clear with little to no sludging.

Acid Number vs. % Tensile

0.0

20.0

40.0

60.0

80.0

100.0

0 0.05 0.1 0.15 0.2 0.25 0.3 0.35

Acid Number

Perc

ent T

ensi

le

Moisture in Oil vs. Percent Tensile

0.0

20.0

40.0

60.0

80.0

100.0

0 20 40 60 80 100 120

Moisture in Oil (ppm)

Perc

ent T

ensi

le

Furan Testing

Equation is Log (Fur) = 4.086 - .0033DP (based on ppb)Equation is Log (Fur) = 1.086 - .0033DP (based on ppm)

Equation from Weidmann website (Chengdong):

Log (Fur) = 1.51 - .0035DP

Log (2-furaldehyde) vs. DPy = -0.003309x + 4.085901R2 = 0.642043

0

1

2

3

4

5

0.0100.0200.0300.0400.0500.0600.0700.0

DP

log

(2-fu

rald

ehyd

e -

ppb)

Log(5-Hydoxy-methyl-furaldehyde) vs. DPy = -0.003214x + 2.968184

R2 = 0.573999

0

1

2

3

4

0.0100.0200.0300.0400.0500.0600.0700.0

DP

Log(

5-H

ydox

y-m

ethy

l-fu

rald

ehyd

e-pp

b)

Log (5-methyl-2-furaldehyde) vs. DPy = -0.003525x + 3.168439

R2 = 0.692426

0

1

2

3

4

0.0100.0200.0300.0400.0500.0600.0700.0

DP

Log

(5-m

ethy

l-2-

fura

ldeh

yde-

ppb)

Furan Testing - Continued

Data appears to be similar for both types of paper

Data correlates well with published data

Log 2-furaldehyde vs. Paper DP

0.0100.0200.0300.0400.0500.0600.0700.0

0 1 2 3 4 5

Log (2-furaldehyde - ppb)

Pape

r DP

Paper DPUpgrade DP

0

1

2

3

4

5

0 200 400 600 800 1000

DuPont-Weidmann Aging Chengdong AgingLinear (DuPont-Weidmann Aging)

DGA Analysis

Log (CO) vs. DP y = -0.0016416x + 4.2348137R2 = 0.3454258

0

1

2

3

4

5

0.0100.0200.0300.0400.0500.0600.0700.0

DP

Log

(CO

- ppm

)

Log (CO2) vs. DPy = -5.749843E-04x + 4.652324E+00

R2 = 5.383712E-02

0123456

0.0100.0200.0300.0400.0500.0600.0700.0

DP

Log

(CO

2 - p

pm)

Gas Concentration vs. DP

y = -0.001311x + 2.215512R2 = 0.314097

y = -0.000742x + 1.286202R2 = 0.083130 0

1

2

3

0.0100.0200.0300.0400.0500.0600.0700.0

DP

Log

(Gas

- pp

m)

Log (H2) Log (CH4)

Pressboard TestingWill evaluate spacer material using mechanical testing (compressibility) and DP. Will evaluate bulk oil insulation using mechanical testing (tensile strength) and DP.

Are starting to get initial results for each.

Cool Board Test DataCooler Board H20 vs. Aging y = 0.0167x + 0.2393

R2 = 0.1399

0

0.5

1

1.5

2

2.5

0.000 5.000 10.000 15.000 20.000 25.000 30.000 35.000 40.000

Aging Factor

H20

Con

tent

Cooler Board Tensile vs. Aging y = -3.5059x + 5326R2 = 0.0019

0

2,000

4,000

6,000

8,000

0.000 5.000 10.000 15.000 20.000 25.000 30.000 35.000 40.000

Aging Factor

Tens

ile S

tren

gth

(psi

)

Little to no correlation here with tensile retention – good, since the cooler board should not be seeing high temperature

Water seems to be collecting in the cooler board –which helps extend the aging of the paper – likely similar to a real transformer

Hot Board Test DataHot Board H20 vs. Aging y = 0.0101x + 0.1915

R2 = 0.1893

0

0.2

0.4

0.6

0.8

1

0.000 5.000 10.000 15.000 20.000 25.000 30.000 35.000 40.000

Aging Factor

Perc

ent H

20

Hot Board Tensile vs. Agingy = -0.6039x3 + 47.032x2 - 1122.5x + 17572

R2 = 0.5482

0

5,000

10,000

15,000

20,000

0.000 5.000 10.000 15.000 20.000 25.000 30.000 35.000 40.000

Aging Factor

Tens

ile S

tren

gth

(psi

)

Hot Board Compression % vs. Agingy = -0.0228x + 3.6654

R2 = 0.0354

0.001.002.003.00

4.005.006.00

0.000 5.000 10.000 15.000 20.000 25.000 30.000 35.000 40.000

Aging Factor

Com

pres

sion

%

Compression Set vs. Aging y = 0.0216x + 0.6368R2 = 0.1537

0.00

0.50

1.00

1.50

2.00

2.50

0.000 5.000 10.000 15.000 20.000 25.000 30.000 35.000 40.000

Aging Factor

Com

pres

sion

Set

Best correlation appears to be tensile retention vs. aging factor.

DP Data - Location within Cell

Next Steps in Testing from 3/06• Complete aging of all paper types• Develop methodology to evaluate the effect of

oxygen (bottled gas with known O2/N2 content) and moisture (suggestions?).

• Need to understand target levels of oxygen and moisture for evaluation. This may also be needed for other two methods in C57.100.

• Conduct additional sealed tube tests with similar insulation configuration.

• Evaluate what criteria should be used to evaluate systems.

Discussion regarding work and how to implement into our document

For example:• What standard conditions (moisture, oxygen)

should be tested to qualify a system, for each of the methods?

• What qualifies a system combination as good (solid data only, solid and fluid data, etc.), for each of the methods?

• Other topics?

Open items from past meetings:

a. IEC document (62332) – still need to get approval for use.

b. Search for other applicable IEC documents.c. Need volunteers to look at sections of document

for the revision of C57.100.- Distribution Transformer Testing (Lockie)- Sealed Tube Test (Annex)

Existing C57.100 Methods

Sealed Tube Method (Annex)

Finish Up meeting