The Feasibility of

Energy Efficiency Standards for

Distribution Transformers

Required by

Section 124 EPACT

P. R. Barnes

Oak Ridge National Laboratory

Power System Technology Program

EE-DET-97-550 COMMENT 0C
i

AGENDA

PROJECT REVIEW MEETING

DISTRIBUTION TRANSFORMER DETERMINATION STUDY

FORRESTAL . BUILDING , ROOM 3E-033

DECEMBER 7, 1994

2:15 ORNL Visitors Check In ...........................................

2:30 Opening Remarks ....................................:. Terry Logee

2:35 Introduction .......................................... Randy Barnes

2:45 Transformer Technology ............................... Ben McConnell

2:55 Distribution Transformer Market .......................... .. .. Sujit Das

3:05 Energy Conservation Options ............................ Jim Van Dyke

3:45 Discussion .................................................... All

5:00 Leave for Airport

EE-DET-97-550 COMMENT 0C
PROJECT TEAM AND SCHEDULE

P. R. Barnes Project Leader EE

B. W. McConnell Physics

S. Das MBA & Eng.

J. Van Dyke Economics

Schedule

Draft Report Submitted to DOE by January 10, 1995.

EE-DET-97-550 COMMENT 0C
DISTRIBUTION TRANSFORMER LOSSES

ARE SIGNIFICANT

ORNL-DWG 94-2116

UTILITY SYSTEM LOSSES 7.5-8.2% CUSTOMERS SYSTEM

r

GENERATION GSU

35% ' 65%

HV LINES MV LINES

►+ TRANSFORMER LOSSES 3.1%

SUBSTATION DISTRIBUTION

TRANSFORM RS

38% '27%

METER

RESIDENTIAL

COMMERCIAL

I NDUSTRIAL

EE-DET-97-550 COMMENT 0C
EFFICIENCY AS A FUNCTION OF LOAD

99.5

99.3

99.1

98.9

98.7

98.5

98.3

98.1

97.9

97.7

97.5

EFFICIENCY

ORNL-DWG 94-1764

0:08 0.24 0.4 0.56 0.72 0.88 1.04 1.2

PER UNIT LOAD (Nameplate Rating = 1.0)

500

450

400

350

w

300

9 250

J

jLC 200

0

150

100

50

0

LOSSES

ORNL-DWO 94-1765

0.16 0.32 0.48 - 0.64 0.8 0.96 1.12

PER UNIT LOAD (Nameplate Rating = 1.0)

EE-DET-97-550 COMMENT 0C
TYPICAL LOSSES FOR A 25 KVA

DISTRIBUTION TRANSFORMER '

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

DRY TYPE UNIT

OLDER UNIT

11

`` -- LOW LOSS

'T I J a 1 I i

0.2 0.4 0.6 0.8 1.0 1.2 1.4

PER UNIT LOAD (Load/Nameplate)

ORNL-DWG 94-1705C

AMORPHOUS

CORE

EE-DET-97-550 COMMENT 0C
STANDARDS NEED TO CHALLENGE

CURRENT PRACTICES

DRY 3-PHASE 45 KVA TRANSFORMER LOSSES

2250

2100

1950

1800

1650

1500

1350

1200

® 1050

900

750

600

450

300

150

0

i

"Imil

TYPICAL

EXISTING

FOR A 45 WA DRY-TYPE UNIT

I V l" itl

III r IL11VII iilli ll,Ibbil,lilll I11I il'Ipillll f

i

jli Ilioil!I!^iiliiliillM ltl!i IIIj ^Ib^!il^

CSA Standard $3.50/2.25

CASES

ORNL-DWO042117

LOAD

NO LOAD

$3.50/$0.75

EE-DET-97-550 COMMENT 0C
Determination Study Approach

Case Studies

• Develop Alternative Treatments

- Address major sources of loss

- Cover utility and non-utility sectors

- Outcome can be analyzed

- Challenges current practice

• Evaluate Cases

Energy savings >.01 quads over 25. years

- Manufacturing feasibility

- Cost effective from a national perspective

Identify impacts on the various stakeholder sectors

EE-DET-97-550 COMMENT 0C
DEC 08 '94 10:29 PSTP ORt'U_

Limitations on Transformer

Performance -Physics of Oil vs.

Dry Designs

Presented to the U. S. Department of Energy

by Ben McConnell

Senior Development Staff

Oak Ridge National Laboratory

P. O. Box 2008, MS-6070

Oak Ridge, IN 37831-6070

December 7, 1994

P.1 T

Post-It" brand fax transmittal memo 787`t r of M" ► Z„

From 1

Ca

Dept. Phone G^ 'S - 3

Fax" _ 4AP 1-7 "' j U15- 57 -7

EE-DET-97-550 COMMENT 0C
DEC 08 1 94 10:29 PSTP ORt'. •P.2

EE-DET-97-550 COMMENT 0C
DEC 08 '94 10:29 PSTP ORNL P.3

EE-DET-97-550 COMMENT 0C
ower Ct Voltage equations

Power in kVA = 4443 *f*N*Bmax*Aclw*J*Acrw,

where f = operating frequency (Hz), N = number of turns in the winding, B, = maximum flux density in the

core (tesla), and Alp = cross sectional area of the core material in the coil window (m2), I is the current density

(A1m2) and Ate„ is the coil cross sectional area of the coil material in the core window (m2)

?,- Volt/Turn = 4.443*f*Bmax*Aclw

EE-DET-97-550 COMMENT 0C
N

a:

>- Depend upon Hysteresis and Eddy Current Losses -

)' Hysteresis Losses are functions of Core Volume, Operating frequency, and Core Magnetic Fier`

?> Eddy Current losses are functions of Core Volume, Operating Frequency, Lamination Thicknessi,

and.Core Magnetic Field

93

EE-DET-97-550 COMMENT 0C
Load Losses

>- Depend upon Eddy Current and Resistive fosses -

?- Eddy Current Losses are functions of Radial Magnetic Field Component2, Conductor Lamination

Thickness2, and Operating frequency.

> Resistive Losses are functions of Conductor Current Density2, Conductor Cross Sectional Area',

and Conductor Length.

9

EE-DET-97-550 COMMENT 0C
DEC 08 '94 10:30 PSTP ORI'L

Loss deduction

Alternative

P.7

No-load Loaw Load LOW C44

LTo Axreae No-Laad Losses

A.Use Lower Laos Cora

Matarisls

Lower Higher W Lower Higher

`

B.Deerease Flux Density by

1.Tucxe si tg Corn CSA' Lower Higher Higher

2.Deerexsiag Yohslfurn Higher or Lower Higher Higher

C.Aocrase P w Pack Length by

L.Decreasing Coaduetnr CSA Lower Higher Lower

ILTO-Deemer Lead Lassa

A.Use Lower Lou Conductor

Mateti><

Higher or Lower Lower Higher

S.Decrraae Current Dewily by

I'lW acing Conductor CSA Higher Lower Higher

C.Decrdse Current Pads Length

by

L.Decretning Cora CSA Higher Lower Lower

2.Ineraeing Volts(furn Lower Lower Lower

LCSA = Cross Sectional Area

EE-DET-97-550 COMMENT 0C
ABB POWER T&D SEMINAR

DRY TYPE TRANSFORMER DIVISION

a law A ;1aaA;, ;& am!%

I I I I

I I I 1

I

I

I I

I I

I

I

I I I I

I I I I

^ t I I

• ,. t iTr®t1 7sair

am 11:;IE=L^ _ -nm_

contaminants

INSULATION SYSTEM

thermal

- dielectric

INSULATION MEDIUM

- dielectric

- tooling

ENCLOSURE

Radiators

I

111 It III 1111111 1

Ii

I

I

I

I

I

I

I

f'

v v w w w w v '

LIQUID FILLED

SEALED DRY'S

COOLING -CLASSES

XF Type Temp Avg HS Max Major

Class Rise Dif f Arab Components

Open Wound 220 150 30 40 Nomex/Air

Sealed Dry 220 150 30 40 Nomex/Seated Gas

Epoxy Cast 150 80 30 40 Epoxy/Air

Li uid Filled 120 65 15 40 Pa er/Fluid

OW/EC Ambient Air

Sealed Dry The Gas - C2F6/N2/SF6

Liquid Fitted The Liquid - oil/silicone/etc.

^-AMBIENT CONDITIONS-S

- altitude

- temperature

Liquid Filled

OA

OA/FA

OA/FA/FA

OA/FA/FOA

OA/FOA/FDA

OW

0W/A

FOA

FOW

Dry Types

AA

AFA

AA/FA

ANV

GA

AA/AA/FA

Insulation Medium ___./

Cooling Medium - Rise #1

Cooling Medium Rise #2

v

m

BASICS & TERMINOLOGY : Insulat ion, Systems Cooling. Medium Rise #3 se".

EE-DET-97-550 COMMENT 0C
ABB POWER T&D SEMINAR

DRY TYPE TRANSFORMER DIVISION

GENERAL

• Predominant Type of Transformer

a Oldest Technology

Established Performance Record

• Best Balance of Design Properties

- Dielectric, Thermal, & Cost

• Basis For Alt Other Types

11

FEATURES

• Hermetically Seated Tank

n Insulation System

- Oit-Impregnated Paper

• Insulation Medium

- Transformer Qt

ADVANTAGES DISADVANTAGES

• Outstanding Thermal Properties • Leakage

• Outstanding Dielectric Properties n Fire

n Lowest Purchase Cost

• Sriatlest Dimensions

n .Lowest Losses per Purchase Dollar

• Unaffected by Environment

SELECTION - Oil Filled Was

EE-DET-97-550 COMMENT 0C
ABB POWER T&D SEMINAR

DRY TYPE TRANSFORMER DIVISION

GENERAL

• The Oldest Type of Transformer

• Dominates Control Powerr and

Instrument Transformer Markets

n Development of Higher Temperature

Materials Allowed Cost Effective

Option to Oil In Small Power

• Flexibility In Design

FEATURES

• 'Dipped' in Varnish

• Insulation ' Classes

- Various Ratings Commonty Used

n Insulation System

- Insulation Paper & Ambient Air

Insulation Medium

- Ambient Air

ADVANTAGES

• Truly Non - Ftommabte

n No Leakage Problem

• Relatively Low Cost

n Light Weight & Smatt Size

- Higher Operating Temperature

DISADVANTAGES

Air is Poor Thermal Conductor

n Ambient Impacts Insulation Medium

n Ambient Impacts Insulation System

- "Dipping' Does Not Effectively Seal

Insulation on Interior of Windings

Especially Pronounced at Higher

Voltage Ratings

n Little Capital Investment Required

- Many Questionable Manufacturers

Enter & Leave The Market

SELECTION - Conventional Dry Types

EE-DET-97-550 COMMENT 0C
ABB POWER T&D SEMINAR

DRY TYPE TRANSFORMER DIVISION

Arrhen;us-,Reaction Rate

to life(t) = A

Class 220: tn(t) = 1650.0/T-22.093

Class 185: t n ( t) = 14222/T-19.671

Class 150: In(t) = 12111/T-17.250

singer. Factor = 10-C

The life of organic materials will

halve or double for every 10'C

change in temperature.

HS AMB RISE

Class 220: 30 + 40 + 150 Consider: Class 220 Operating at 115'C Rise

Class 185: 30 + 40 + 115 HS Rse LIFE

Class 150: 30 + 40 + 80 220 150 4.5

Avg Arab = 20`C vs 40'C Max 210 140 9 = (2)4.5

200 130 18 = (2) (2)4.5

Life = (2)(2)(4.5) = 18 years 190 120 36 = (2)(2)(2)4.5

180 110 72 = (2)(2)(2)(2)4.5

SPECIFICATION - Overloading & Life IL"M

EE-DET-97-550 COMMENT 0C
Are Lower Loss Dry Type Transformers

Technically and Economically Feasible?

9

?- Yes, but because air is the basic cooling and insulating medium,

the costs and losses will always be higher than an oil filled unit.

However, the system must also be considered. Where is the unit

to be used, what is the equivalent installed cost, and what are the

run losses? Be careful about comparing only the transformer

efficiency and cost.

Never-the-less, dry transformers could be made more efficient

without apparent significant technical problems.

EE-DET-97-550 COMMENT 0C
CONSERVATION CASES

James Van Dyke

Oak Ridge National Laboratory

EE-DET-97-550 COMMENT 0C
Conservation Cases

n Preliminary results

e Definition of Cases

Oak Ridge National Laboratory December 7, 1994

EE-DET-97-550 COMMENT 0C
Potential Energy Savings

for National Perspective Regulation

21000

11500

cn

0

1,000

500

Total Annual Savings in the

first year would be equivalent to

a 300 MW Coal Fired Power

Plant or 0.0058 Quads

Dry Type

Liquid Type

0-100 >100 0-15 15-100 >100 Total

Type and Size

EE-DET-97-550 COMMENT 0C
Distribution of Savings

(Watts per KVA)

0.5-1.0 1.0-1.2

0-100 >100 0-15 15-100 >100'

Size: and Type of Transformer

EE-DET-97-550 COMMENT 0C
Watts of Savings per KVA

for Alternative Standards

14

<12

11

^- 10

a 9

cn0) 7

•5 6

5

,^- 4

o 3

N 2

`u o

-1

-2 I

LIQUID 25

LIQUID

I I

DRY

50 50.01 150 750 2000 DRY 1 10 45 1500 2000 2500

Size and Type of Transformer

Note: 1 Watt per KVA for Total Annual

Transformer Sales = 0.003 Quads

annually or electric output from a 150

MW Coal Fired Power Plant operating at

65% Capacity Factor

° National Perspective Losses

Utility Evaluation (80%)

NLL Regulation Only

EE-DET-97-550 COMMENT 0C
Approach

e Find losses for cost-effective designs

through survey of manufacturers

• May appeal to users because of life-cycle cost

savings

• Appealing to manufacturers because of higher

sales revenue

n Develop alternative cases from survey

information

Oak Ridge National Laboratory December 7, 1994

EE-DET-97-550 COMMENT 0C
12 Different Transformers Were

Surveyed

n Liquid Filled Single

Phase

n 25 KVA Pole

n 50 KVA Pole

n 50 KVA Pad

Liquid Filled Three

Phase

n 150 KVA Pad

n 750 KVA Pad

n 2000 KVA Pad

® Dry Single Phase

n I KVA

n 10 KVA

Dry Three Phase

n 45 KVA Lighting

n 1500 KVA Epoxy Cast

n 2000 KVA Load Center.

n 2500 KVA Epoxy Cast

Oak Ridge National Laboratory December 7, 1994

EE-DET-97-550 COMMENT 0C
Survey form:

n For $3.50 and $2.25

• No Load Losses

• Load Losses

• Selling Price

n For $3 . 50 and $0. 75

• No Load Losses

• Load Losses

• Selling Price

Oak Ridge National Laboratory

n For $0 . 00 and $0 . 00

• No Load Losses

• Load Losses

• Selling Price

• This served as the basis

for Existing Dry

Transformer Losses, i.e.

the Base Case

December 7, 1994

EE-DET-97-550 COMMENT 0C
Survey response

e 163 designs

n At least 3 designs were submitted for

each A/B combination

n As many as 7 designs were submitted on

some transformers

Oak Ridge National Laboratory December 7, 1994

EE-DET-97-550 COMMENT 0C
Issues in Defining Cost

Effective Designs

s Uncertainty in factors determining the

cost of losses

• Dependent on Load Factor

Life of Transformer

• Varies with cost of fuel and capital

Manufacturers' ability to anticipate and

Liquid Filled

Dry

reveal" cost effective designs

Oak Ridge National Laboratory December 7, 1994

EE-DET-97-550 COMMENT 0C
Divergence of TOC and design '

losses

TOC' s for transformers which are

evaluated are much closer than for

traditionally unevaluated transformer

e Can we trust the results?

• Sandbagging

• Lack of experience in designing low loss

transformers

Oak Ridge National Laboratory December 7, 1994

EE-DET-97-550 COMMENT 0C
Formulation of alternative

Cases

n Base Case

n National Perspective Case

E"9 U tility Evaluation Case ( Based on Maximum Losses

Consistent with 80% of Uti l ities' Evaluation Criteria)

n NO Load LOSS Only Case (eased on Lowest No

Load Losses submitted in survey and highest load losses)

Oak Ridge National Laboratory December 7, 1994

EE-DET-97-550 COMMENT 0C
Canadian Style Tradeoff

n Allows flexibility within guidelines

• Manufacturer adjusts to reflect strength/weakness

Users can .reflect loading practices

n Selecting tradeoff corresponding to ratio of A to B Factor results in

constant value of losses

n Systematic preference for lower No Load losses emphasizes

energy savings

n Systematic preference for lower load losses emphasizes capacity

savings

Oak Ridge National Laboratory December 7, 1994

EE-DET-97-550 COMMENT 0C
for Alternative Standards 

Savings per KVA--Dry Transformers 

i 

1 

i 

d 

Size of Transformer 

Aggregate Savings 

Annually: 

1 Watt for all Liquid 

Transformers = 50 MW 

Baseload Plant 

National Perspective Losses 

Utility Evaluation (80%) 

+- NLL Regulation Only ii 

EE-DET-97-550 COMMENT 0C
Savings per KVA--Liquid Transformers

for Alternative Standards

a)

X 0.8

0 .. 6

b O.4 U)

0.2

3: 0

CA;

CID

a

25 50 50.01 150 750 2000

Size of Transformer

e National Perspective Losses

m Utility Evaluation (80%)

EE-DET-97-550 COMMENT 0C
THE ANALYSIS OF

EE:GY CONSERVATION STANDARDS FOR

DI jTION TRANSFOPMERS AS REQUIRED BY

SUBTITLE C, SECTION 124

017 THE ENERGY PC Y ACT OF 1992

QUARTERLY REVIEW

P. R. Birnes

Energy visi

Oak Ridge National Laboratory

PROJECT O ERVIEW

June 13,1994

Work sponsc,-ed the

Office of Ener, Management

U_ S. Departmesi of Energy

Prepare(i by the

OAK RIL G E NATIONAL ]LABORATORY

Oak Ridge, Tennenee 37831-6285

manage; by

MARTIN M IFI A Elk-HRGY SYSTEMS, INC.

for Ile

U.S. D P THE T -O ENERGY

under contract DE-zCb*-34OR21

EE-DET-97-550 COMMENT 0C
TOPICS

Introduction and Project Scope

Overall Approach

• Planned Schedule

• Present Status

EE-DET-97-550 COMMENT 0C
CXPBL-CVWG 94-

1950 1955 1960 1965 1970 1975 1980 1985 1990

- TIME (year)

99.1

99.0

9&9

98.8

98.7

.6

.5

98.4

3

98.2

98.1

_0

(a.) Transmission and distribution system efficiency (Source: DOE/EIA-0384(92})

1950 1960 1970 1980

TRANSFORMER YEAR OF MANUFACTURE

(b.) Maximum efficiency of a typical 25 WA dist ution transformer.

9a-1899

1990

F . I.I.:i he 'c utility transmik . on and di^-trib 'on efficiency improvements

EE-DET-97-550 COMMENT 0C
25 TRANSFORMER COST & L -.USES

500

400

0

$348(; 20 $465 $486 $538 $573 $5 99 $662

TRANSFORMER 1ST COST

-^- COST -- N LL 5 ^ LL 25

EE-DET-97-550 COMMENT 0C
A ° TO FROM UTfA SURVEY

EVALUATION OF NO LOAD LOSSES

$10.00 -

$9.50

$9.00

$8.50

.$8.00

$7.50

$7.00

$6.50

$6.00

S

$5.50

$5.00

$4.50

$4.00

$3.50

- ® - -----! --- $3.00

$2.50 n -

$2.00-_.-_

$1.50

$1.00

---- ___ - n "^. $150

°0 HHH!

UTILITI ES

EE-DET-97-550 COMMENT 0C
B FACTORS h r M UTILITY UR ' Y

EVALUATION OF LOAD LOSSES

$3.00

$2.90 ----

$2.80 ----

$2.70

$2.60 ----

$2.60-

V

$2.40

$2.30

$2.20

$2.10

$2.00 _^ n ! - $1.90

$1.80

$1.70

o_ $1.50

co $1.40

$1.30

$1.20

$1.10

s..11 $1 . 00

_J $0.90

O $0.80

$0.70

$0.60

$0.50 ® ----------

$0.40

$0.30

$0.20

$0.10 $0.00

UTILITIES

EE-DET-97-550 COMMENT 0C
FOM USING AV. ERGY USE

25 KVA TRANSFORM ERS '=ROM SU RVE'

u, 140

120

w

YJ

100

w

z

w

w

CD

w

80

60

Q 40

.

........................................... .

n

-

.

n

8 12 1 29 38 243 54 59 63

UTILITIES IN VEY

EE-DET-97-550 COMMENT 0C
Effective Dates For Energy Efficiency Requirements

Under the Energy Policy Act of 1992

Utility Distribution Transformers

Standards Testing Procedures bellr^^ ° r `:

Effective Date Effective Date Effectiv. mate

Utility Distribution DOE shall prescribe standards by DOE shall prescribe testing DOE shall prescribe labeling rules by

Transformers October 24, 1991to be effective procedures by April 24, 1995. April 24, 1997, to be effective for

for transformers manufactured after transformers manufactured after

such date or a later date , as DOE October 24. 1997.

determi .

For pore information contact Kyle Pitsor, NEMA Government Affairs., at

(202) 457-8448. Fax (202) 457-8411.

EE-DET-97-550 COMMENT 0C
DETERMINATION STUDY

DETERMINE STANDARDS AR

'II CHNOLOGICALLY FEASIBLE

EC NOviICALLY JUSTIFIED

SIGNIFICANT SAVINGS WOULD RESULT

DOE TO DEVELOP STANDARDS AND TESTING AND

LABELLING REQUIREMENTS

EE-DET-97-550 COMMENT 0C
DETERMINATION STUDY APPROACH

1. BUILD A DATA BASE:

a) Utility survey data

b) NEMA loss and sales data

c) Manufactures data

d) Other sources

2. DEVELOP OR OBTAIN MODELS FOR ANALYSIS

a) Forecasting models

b) Economic and energy savings models

3. DEVELOP CASES FOR ANALYSIS

a) Cases should be practical and analyzable

b) Utility and non utility sectors

4. EVALUATE THE CASES

a) Are there significant energy savings - .01 quads over

25 yrs ?

b) Are they to '-^nclogical feasible ?

c) Are they co effective from a national perspective ?

Which consun-i -,rs are penalized ? What percentage ?

d) Reconmern ` ations for a standards s :udy

EE-DET-97-550 COMMENT 0C
Planned Schedule

The following milestones have been identified:

Milestone

Begin Data Collection x/94

NEMA Sales Data and Dry-type

Efficiency Data Request 5/09/94

Determine LFs and A&Bs for ea size unit 6/20/94

Additional NEMA Data Request 6/09/94

Receive NEMA Data 7/3j/94

Complete Sales and Use Assessments 7/31 /94

Complete Technical And

Economic Assessments 9/3"2/94

First Draft Report 11/25/94

Revised Draft Report 12/31/94

EE-DET-97-550 COMMENT 0C
PRESENT STATUS

Have Part of the Data _" 4 eeded

Additional data request have been made to NEINLA,

cork has begun on moel and case development

More details in the presentations to follow

EE-DET-97-550 COMMENT 0C