Power

Tran

sfor

mers

Econ

omicsof

Refur

bish

men

tvsRep

lace

men

t

Pres

enter:

Moh

ammad

RSidd

iqui

Nationa

lGrid,

Saud

iArabia

CoAutho

rs:A

bdullahOBa

mou

saNationa

lGrid,

Saud

iArabia

Introd

uction

•Th

ispa

perisb

ased

on–

•Dataob

tained

from

theGrid

•Interaction

with

some

Tran

sformer

man

ufacturers.

•Te

chnicalPa

pers

publishe

don

the

diffe

rent

compo

nents

ofPo

wer

Tran

sformers

•Ong

oing

Projects

intheGrid

TheNee

dto

Refur

bish

/Ren

ovate

•In

theearlyseventies,

Utilities

wen

tfora

HV

Tran

smission

Level

of110

kV/132

kV.

•In

theWestern

Region

Grid,2

38of

atotal

of730

Tran

sformers

were

commission

edbe

tween

1975

to1985

.Th

eywou

ldbe

30to

40yearsby

the

year

2015

Tran

sfor

mer

sC

omm

issi

onin

gD

etai

lsfr

om19

75to

1985

inW

OA

Nat

iona

lG

rid

Are

a

Year

ofC

omm

issi

onin

g

Tota

lFr

omTo

From

To

1975

To19

8019

81To

1985

JED

DA

H79

5213

1

MA

KK

AH

1927

46

TAIF

1014

24

MA

DIN

AH

Nil

2525

TAB

OU

KN

il12

12 238

Spec

ific

Prec

eden

ce

In1971

thefir

stfour

110/13.8kV

Tran

sformers

were

put

inservice

.Tw

oeach

inCity

Substation

andDSP

Substation

inJedd

ah

Thetw

oTran

sformersin

CitySu

bstation

were

servingon

fullload

andha

dto

bereplaced

2yearsba

ckne

ar

The2Tran

sformersin

DSP

Substation

were

notfully

load

edan

darestill

inservice.

This

raises

thefollow

ingissu

es

•To

determ

inetheag

ingeffect

ontheun

its

•Step

stobe

take

nto

mak

eade

cision–whe

ther

replaceor

refurbishtheUnits.

Aging

depe

ndson

•Th

eload

ing

cycles

that

the

tran

sformersha

vebe

ensu

bjected

toov

ertheyearsa

nd

•Th

eNum

berof

Throug

hfaults

that

theTran

sformer

hass

uffered

Agingis

best

establishe

dby

•Ex

ternal

inspection

oftheTran

sformer

anditsA

uxiliary

equipm

ent.

•Insulating

Streng

thof

theTran

sformer

Oil.

•DGAAna

lysiso

fthe

Tran

sformer

Oil

•Freq

uenc

yRe

spon

seTe

st(Previou

sRe

ferenc

eRe

sults

necessary)

•Bipo

larT

est

Plan

ned

stud

yan

dtim

ely

replacem

ent/refurbishm

ent

will

preven

tsu

dden

deaths

ofTran

sformers

that

resu

ltin

unplan

ned

outages

and

possible

extend

edda

mages.

APo

wer

Tran

sformer

isa

stationa

ryde

vice

anddo

esno

tcon

tain

compo

nents

that

requ

ire

precision

Engine

ering.

Disman

tling

aTran

sformer

and

replacingtheco

mpo

nentsisrelativ

elyan

easy

proc

edure.

Thepictures

inthefollo

wingslides

show

diffe

rent

stages

ofassembly

and

dism

antling

ofthe

Tran

sformer

indiffe

rent

location

s

InWorksho

p

Gen

erally

theco

mpo

nent

sth

atremainintact

over

theye

arsare:

•Th

eMain

Tank

•Th

eCo

rean

dFram

e•

TheEx

ternal

Metallic

fittin

gs–Con

servator,

Piping

,Rad

iator

•Th

eMecha

nicalP

rotectionDevices

and

ControlC

ubicles

Theco

mpo

nent

sth

atne

edinsp

ection

before

deciding

replac

emen

t/reus

e:

•Ta

pCha

nger

/DiverterS

witc

h.•

CoolingFa

ns.

•Protectio

nDevices.

•Bu

shings.

•Cu

rren

tTrans

form

ers.

Major

Com

pone

ntsto

bereplac

ed:

•Th

eCo

ilsform

ingtheH

V/LVW

inding

sha

veto

bereplaced

•New

Gaske

tsfors

ealin

gan

dco

nsum

ables

•Pressb

oard

materialu

sedforins

ulation

andspacing.

Com

pariso

n:

•Th

eco

stof

ane

w40

MVA

110/13.8kV

Tran

sformer,

includ

ingDesignMan

ufacturing

,Trans

portation,

Installatio

nTe

sting&Co

mmission

ing

in20

12is2.8to

3.2mSR

anda67

MVA

trafoco

sts3

.5to

4.0mSR

•Re

furbishm

entof

anexistin

g40

MVA

Tran

sformer

will

costab

out1.5

mSR

.Th

eco

stof

refurbishm

ento

faTran

sformer

isab

out5

0%

asco

mpa

redto

theco

stof

replacem

ent.

•Be

lowisaco

stco

mpa

risonTa

bleba

sedon

inform

ationexch

angedwithsomeman

ufacturers.

Item

Des

crip

tion

as%

ofto

talc

ost

ForN

ewTr

afo.

ToR

efur

bish

1D

esig

n5

0

2P

roje

ctM

onito

ring,

Inst

alla

tion

Test

ing

&C

omm

issi

onin

g15

53

Tran

spor

tatio

n+

Dut

y15

5

4Tr

ansf

orm

erC

ompo

nent

s4.

1C

oil

2012

4.2

Cor

e7

0

4.3

Tank

,Con

serv

ator

,Rad

iato

rs,

Pip

ing,

Gas

kets

,Con

sum

able

s,fa

nsan

dC

ontro

lCub

icle

s12

2

Item

Des

crip

tion

as%

ForN

ewTr

.To

Ref

urbi

sh

4.4

Coo

lant

-Tra

foO

il8

5

4.5

Mec

hP

rote

ctio

ns,C

Ts5

2

4.6

Tap

Cha

nger

105

5Fa

ctor

yTe

sts

33

6D

ism

antli

ngan

dA

ssem

bly

010

Tota

l10

0%49

%

In20

06a

100M

VA13.8kV

/132kV

Tran

sformer

had

allitsW

inding–

HV

and

LV,replaced

for1.3

mSR

.Th

eco

stof

such

Tran

sformer

then

was

abou

t5mSR

.

•238Tran

sformersin

theWestern

Region

will

be30

40yearso

ldby

2015.If10%

ofthese238Tran

sformersare

iden

tifie

dforrefurbishm

enteach

year

over

thene

xtten

years

,it

will

berequ

ired

torefurbish

one

Tran

sformer

every2weeks.

•If

extend

edto

the

entire

Cou

ntry

that

has4

such

Region

sin

all,

the

refurbishm

ent

rate

can

beestimated

as4

Tran

sformers

in2

weeks

that

is2

Tran

sformersp

erweek.

•MoreTran

sformerswill

fallin

this

catego

rywith

each

passing

year.

•An

Assem

blyplan

tspon

sored

bythe

Utility

wou

ldbe

idealtotake

upthis

workas

theorde

rbo

okwill

befullforthe

next

soman

yyears.Itwill

beafir

ststep

towards

indigeno

usHeavy

Indu

stry

for

prod

uctio

nof

Tran

sformers

and

gene

rate

employ

men

tforskilled

andsemiskilled

worke

rsin

theco

untry.

ANew

Team

will

have

tobe

setu

p.

•Alte

rnativelyit

can

beou

tsou

rced

toon

eof

the

compa

nies

working

with

the

requ

ired

facilities

with

intheKingd

om

ADVA

NTA

GES

OFREF

URBISHMEN

T:

•CostS

aving.

•Node

sign

cost.

•En

vironm

entfrien

dly.

•NoCivilWorkrequ

ired

.•

Con

trol

andIndication

srem

ainun

chan

ged.

•Sh

ortc

ycleop

eration–Can

beaimed

for16

weeks.

DISADVA

NTA

GES

:

TheRa

ting

oftheTran

sformer

hastobe

retained

,itc

anno

tbe

increased.

Facilities

need

ed

1.Aworksho

pwithsu

itab

leun

Tank

ingfacilitieso

fthe

Live

Partan

dreplacem

ento

fcoilsby

newon

es.

2.Arran

gemen

tofW

ashing

andClean

ingof

MainTa

nkan

dCorean

dretigh

tening

ofCore.

3.Ovenfacilityford

ryingtheassemblybe

fore

sealingfor

tran

sportation

.4.

Testingfacilitiesfor

theTran

sformer

andits

compo

nents.

5.Su

fficient

Storagean

dha

ndlin

gfacility.

6.Oilregene

ration

unit(atsite

)withOilTa

nksfor

treatm

enta

ndstorage.

TheTran

sformer

oilw

illha

veto

beregene

rated.

Theco

stof

regene

ratio

nisab

out6

0%

asco

mpa

redto

theco

stof

newoil.Th

isisan

environm

entally

friend

lyproc

edurean

dthesuccessr

ate

asexpe

rien

cedin

theexistin

gsubstatio

nsis100%

.

Pastepicture

Con

clus

ion

•Th

erefurbishe

dTran

sformer

will

have

alife

nearlyas

good

asthat

ofane

wTran

sformer,as

stud

ieso

fthe

silic

onsh

eets

used

toform

the

core

oftheTran

sformersh

averevealed

noag

ing

effect.

•Th

epu

rposeof

thispa

peristoinitiateahe

althy

discus

sion

onthissubjecttotake

timelystep

sto

tack

lethesituationthat

wou

ldarisein

coming

years.