ELECTRICAL TECHNOLOGY

WEIDMANN DIAGNOSTIC SOLUTIONS INC.A Member of the WICOR Group

WEIDMANN Electrical Technology

Presentation

at

NETA Trade Show

March 15th, 2016

WICOR WORLDWIDE

Company Overview

INSULATION - Power Transformer

Company overview

Insulation - Distribution Transformers

Insulation Overview

A

C

F

E

B

HV

Winding

LV

Winding Winding

HV3rd

Winding

Voltage BIL

< 15

25

34.5

46

69

115

138

161

230

110

150

200

250

250

350

350

450

550

450

550

550

650

750

650

650

750

E

DCBA

SETTING VOLTAGES CLEARANCESVOLTAGES & BIL

APPLIED

Insulation Clearances for NSF and NBSL Designs

34

50

70

95

95

140

140

185

44

60

80

100

140

140

180

100

- -

--

--

-

-

-

-

-

-

208

208

120

120

180

180

230

185

230

275

230

275

325

275

325

220

180

220

260

220

260

300

260

300

208

251

251

251

295

295

295

415

415

120

145

145

145

170

170

170

240

240

180

215

215

215

250

250

250

364

364

A B C,D,E,F44

60

80

100

100

140

80

60

44 44

60

80

140

100

100

140

100

140

185

230

185

230

275

230

275

325

275

325 325

275

325

275

230

275

230

185

230

185

140208

208

230

251

251

275

295

295

325

415

415

115

76

115

115

44

67

67

.750

.750

.813

.875

.875

1.125

1.125

1.313

1.625

1.313

1.625

2.000

1.625

2.000

2.375

2.000

2.375

1 HR INDUCED

LEVEL

PHASE-PHASEPHASE-PHASE

LEVEL

1 HR ENHANCED

DELTA CONN. WYE CONN.

PHASE-GROUND

LEVEL

1 HR ENHANCED60 HZ BIL

EQUIVALENT

REV

MAT OFSH.SCALE

DRAWING NUMBERSIZE

CONTRACT APPROVAL

CONTRACT NUMBER

DATE

ENGR.

CHECKED

CREATED St. Johnsbury, VT 05819

CUSTOMER NAME CUSTOMER REF NO.

TITLE

PROJECTIONTHIRD ANGLE

DRAWING NUMBER:

BY

FIRST ANGLE PROJECTION

BR e l e a s e 1 . 0

1.313

1.313

1.313

1.09

1.313 1.09

1.09

1.09

1.313

1.375

2.000

1.326

1.326

1.326

2.625

2.375

2.625

3.250

3.250

2.625

2.500

2.500

2.000

2.000

2.375

1.750

1.750

2.375

2.7504.500

4.500

3.625

2.625

2.750

5.000

4.000

5.000

4.000

3.250

4.000

3.250

2.625

3.250

2.625

1.875

1.875

1.625

1.625

1.500

1.438

1.438

C

3/04/93

345 900

900

825

395

395

360

415

415

624

240

240

360

415

415

360

395

395 624

360

395

395

C

TX Jack Ring

1

330

360

360

6.250

7.2506.125

5.3752.750

3.125

364

364

546

1

7.250

6.250

1.438

1.438

1.500

1.625

1.625

1.875

1.875

2.625

3.250

2.625

3.250

4.000

3.250

4.000

5.000

4.000

5.000

SK3493WP1

3.000

3.250

TX Rings

BIL / 2.5

WITH

STATIC

RING

Steel Jack Ring

Core - Jack Ring Allowance

D

Phase 1 Phase 2

C

Note: 1. Both C and C1 Minimums must be maintained.

3. When Static Plates are not present, take

End Clearances from insulated conductor.

2. End Clearances are taken from insulated

static plate.

1

Insulaton Clearances for

Non-Steep Front/Non-Switching

Surge Designs

1 1

SK3493WP1

Top Yoke or Jack Pad

Bottom Yoke or Core Clamp

Core leg

SECTION VIEW

SECTION VIEW

PHASE-PHASE

LV COIL HV COIL HV COIL HV COILPHASE 1 PHASE 2

• Analyze Actual Design• Develop New Design• Analyze New Design• Define Clearances• Define Insulation Layout

Insulation System Design & Optimization

Insulation Overview

• Accredits competency of a laboratory to perform tests to industry standards:

IEEE, IEC, ASTM.

• Rigorous requirements on employee competence, mgmt systems, equipment

calibrations, laboratory physical environment, verification standard testing.

• Assure customers that laboratories follow standard exactly.

• Annual audits by 3rd party auditors

• Only testing laboratories in US to have accreditation

What sets us apart from our competition…

ISO 17025

Progressive Diagnostics

End User Segment - Diagnostic ServicesOil Testing

<2007

Original Labs 2000:

Sacramento, CA

Houston, TX

Calgary, AB

Philadelphia, PA

Indianapolis, IN

2005

Burlington, ON

2007-2008

Waukesha, WI

2009

Montreal, QC

Denver, CO

St. Johnsbury, VT

(R&D)

2010

N. Canton, OH

Saltillo, Mexico

Shanghai, China

TBD

Poland

Brazil

Middle East

Diagnostic Solutions Service Centers

Hubs/Satellites

Progressive Diagnostics

ENGINEERING SERVICES

Ba

Yoke

• OEM and Utility Transformer

Engineering Design and

Specification Analysis

• Power system(grid) analysis

• Power electronics

• 2D & 3D Electromagnetic studies

for AC and HVDC transformers,

rectifiers, switchgear, surge

arresters, etc.

• Failure analysis

• Fleet Assessment

• Condition Assessment

• Thermal upgrades

• Factory and field inspections

• Commissioning/Decommissioning

Progressive Diagnostics

• Technical Conferences • Annual Client Technical Conf.

• Power Transformers Insulation

• Transformer Fluid Diagnostics

• Substation Maintenance and

Diagnostics

• Regional/Local Seminars

• Group Training Events

• Customized training

Offer Continuing Education Credits and IEEE and NETA Accreditations

EDUCATION, TRAINING, AND KNOWLEDGE TRANSFER

Information Management

MONITOR PORTFOLIO / InsuLogix® - GROWING FAMILYFOR OPTIMUM PERFORMANCE MONITORING (OPM)

B - Bushing

T Mi F - Smart Insulation™

H HM Q Multigasand Moisture

D - Dielectric Strength

Health Index(T,Mp)

eNamePlate®(T)

OPM™(T,Mi,F)

2013

2010 2015 2016

2011 2013 2015

2012

2014

2015

2016

Sensors and Monitors SoftwareIntegrator

Platform

InsuLogix® Q

Integrator

WEIDMANN

Monitoring

Complimentary Products and Logistics Services

Warehousing and Inventory Mgmnt\

Insulation Overview

Moisture in Insulation and Transformer Dryout

TOPICS

1. Effects of moisture in Insulation

2. Moisture Absorption and Removal

3. Transformer Dryout Theory

4. Side effects on Dryout Process

Ref. S.D. Meyers

Typically 90% of the initial moisture content will be removed to achieved a dryness of 0.5% moisture content

Paper and Water in TransformersKVA Weight of 5% Initial Moisture

Rating KV Paper (kg) kg/KVA Kilograms Liters

3,000 13.2 453.6 0.15 22.7 23.1

10,000 115 1,605.7 0.16 80.3 81.8

16,000 115 1837 0.11 91.6 93.1

20,000 132 2612.7 0.13 130.6 132.9

30,000 154 3637.8 0.12 181.9 185.1

40,000 230 4808.1 0.12 240.4 244.5

DISTRIBUTION OF WATER IN INSULATION

Oil

HIGH MOISTURE CONTENT IN INSULATION CAN CAUSE:

• Significant Reduction in Dielectric Strength

• Accelerated Aging of the Cellulose

• Bubble Formation and Dielectric Failure

• Partial discharges in the Insulation

Dry � Cellulose < 0.3% by weight

& Oil < 10 ppm H2O

MOISTURE CONTENT VS KV BREAKDOWN VOLTAGE

Source: FM Clark – Engineering Guide Book on Electrical Insulation

0

10

20

30

40

50

60

30 40 50 60 70 80 90 100

Temperature (°C )

Vo

lta

ge

U(k

V)

x = 1%

x = 4%

x = 6%

x = 8%

x = 10%

0

5

10

15

20

25

30

30 40 50 60 70 80 90 100 110

Temperature (°C )

Po

we

r fa

cto

r ta

n (

%)

x = 1%

x = 4%

x = 6%

x = 8%

x = 10%

Moisture

Content

Moisture

Content

KV Breakdown

Power Factor

MOISTURE IN SOLID INSULATION

MOISTURE ACCELERATES AGEING PROCESS

Source: H.P.Moser - Transformerboard

Critical temperature for bubble evolution

50

70

90

110

130

150

170

190

0 2 4 6 8 10

WCP % w/w

Tem

pera

ture

Kobayashi rapid heating

Kobayashi slow heating

Davydov

Oommen gas free

Oommen gas saturated

Ref. Sparling, Brian; GE Energy,

Topics

1. Effects of moisture in Insulation

2. Moisture Absorption and Removal

3. Transformer Dryout Theory

4. Side effects on Dryout Process

WHY DOES CELLULOSE ABSORRB WATER

CHEMICAL BACKGROUND

Due to the high number of hydroxyl-groups is the cellulose molecule very

hydroscopic; meaning, these groups attract water molecules (H2O).

HO

HO

O

OH

CH2OH

O

CH2OH

OH

HO O

n - 2

CH2OH

OHHO

O

OH

HOW MUCH WATER IS ABSORBED (AFTER LONG EXPOSURE TO AMBIENT)

The amount of absorbed water is mainly governed by the relative humidity of the environment. It is hardly influenced by the type of cellulose used.

The (relative) amount of water is not (or only marginally) dependent on:

• The thickness of the board / paper

• The density of the board / paper

• Temperature

• Oil impregnation (without / with oil)

HOW MUCH WATER IS ABSORBED (AFTER LONG EXPOSURE TO AMBIENT)

Moisture equilibrium of Transformerboard

at 23°C and 50% rh conditioned

5

5.5

6

6.5

7

7.5

8

3.2 4.2 1 3 5 8 3.2 4.2 1 3 5 8Thickness [mm]

Wate

r co

nte

nt

[%]

not oil impregnated oil impregnated

low density low densityhigh density high density

HOW FAST IS WATER ABSORBED

How fast water is absorbed is governed by:

• The thickness of the board / paper

• The density of the board / paper

• Temperature

• Oil impregnation (without / with oil)

• Circulation of the surrounding medium (air / oil)

HOW FAST IS WATER ABSORBED

Influence of the thickness

Transformerboard T IV

0

1

2

3

4

5

6

7

8

0 7 14 21 28

Time [days]

Wa

ter

ab

so

rpti

on

[%

]

1 mm

3 mm

5 mm

8 mm

HOW FAST IS WATER ABSORBED

Influence of the densityBoard thickness 3 mm

0

1

2

3

4

5

6

7

8

0 7 14 21 28

Time [days]

Wa

ter

ab

so

rpti

on

[%

] 0.85 g/cm³

1.25 g/cm³

HOW FAST IS WATER ABSORBED

Influence of the temperature

Transformerboard T IV, 3 mm

0

1

2

3

4

5

6

7

8

0 7 14 21 28

Time [days]

Wa

ter

ab

so

rpti

on

[%

]

30°C

10°C

HOW FAST IS WATER ABSORBED

Influence of the oil impregnation

Transformerboard T IV, 3 mm

0

1

2

3

4

5

6

7

8

0 7 14 21 28

Time [days]

Wa

ter

ab

so

rpti

on

[%

]

not oil impregnated

oil impregnated

HOW FAST CAN WATER BE REMOVED FROM TRANSFORMERBOARD

The drying process is a diffusion process.

The rate of drying is therefore governed by the same parameters:

• Temperature

• Pressure

• Material thickness

• Material density

• Oil impregnated (without / with)

Topics

1. Effects of moisture in Insulation

2. Moisture Absorption and Removal

3. Transformer Dryout Theory

4. Side effects on Dryout Process

VACUUMING WITHOUT APPLICATION OF HEAT

Heat of Vaporization – Energy required to change from Liquid phase to Vapor phase

Study indicates that Vacuuming without application of heat :- No further benefit if > 24 hours - “free water @ room temperature freezes @ 4 torr”- “ heat of vaporization would lower the temperature to a point where remaining water will freeze making extensive vacuuming pointless”

Temperature >

..<

V

ac

uu

m L

eve

l

Good Practice – Application of Heat multiple times during the Dryout Process

Topics1. Effects of moisture in Insulation

2. Moisture Absorption and Removal

3. Transformer Dryout Theory

4. Side effects on Dryout Process

SIDE EFFECTS OF DRYING PROCESS

1. Effects on DP

EFFECTS ON DPEXPERIMENT

� Thin high-density pressboard samples (1 mm)

� Oven temperature: 105°, 120°, 140°C

� Time: 14 days

� Hot air circulation vs. Vacuum

� DP measurements during drying.

EXPERIMENT – RESULT:

Transformerboard T IV 1 mm Drying in air

Transformerboard T IV, 1 mm, Aging in Air

0

200

400

600

800

1000

1200

1400

0 2 4 6 8 10 12 14

Days

Degre

e o

f P

oly

merisatio

n

105 °C

120 °C

140 °C

EXPERIMENT – RESULT:

0

200

400

600

800

1000

1200

1400

0 2 4 6 8 10 12 14

Time (days)

De

gre

e o

f P

oly

me

ris

ati

on

105 °C

120 °C

140 °C

vacuum

vacuum

vacuum

Transformerboard T IV 1 mm Drying in air and in vacuum (dashed lines)

POWER TRANSFORMER

DP record: Pulp 1350 // new insulation 1200 // after drying 1000

EXAMPLE: Transformer life starts with DP 1000 versus 1200

CONCLUSION

Loss of transformer lifetime due to insulation drying: → noticeable but not worrying

� DP0 1200 → 40 years

� DP0 1000 → 38½ years� DP0 800 → 36 years

[T.V. Oommen, L.N. Arnold]

THANK YOU

Questions??