14_Bergmann_HV TR.pdf

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HIGH VOLTAGE TESTING ON

TRANSFORMERS

CE

CEPE

PED 20

D 2013

13, Bal

, Balii, Ind

, Indon

onesi

esia

a

Dr

. R

alf B

ergm

ann

HIGHVOLT Prüftechnik Dresden GmbH

(2)

T

Ta

abl

ble

e of c

of con

ontent

tents

s



Motivation and Standards



Factor

Factory T

y Testin

esting –

g – Lates

Latest T

t Techno

echnology

logy



On-Site T

On-Site Testing –

esting – Same principle

Same principle

(3)

MOT

IV

A

TI

ON

AN

D

STANDARDS

(4)

Motivation

E

Eaarly recognitrly recognit ion of:ion of:

 Design issuesDesign issues

 Production failuresProduction failures

(5)

Motivation

 Transformer -Transformer - Key Key compocompo nentnent in electric energy systemin electric energy system

 SSeecurincurin g g TTransformers‘ ransformers‘ qualityquality essential essential for for reliability of reliability of electricelectric network

network

 EExtensive testingxtensive testing within developwithin development and testing of ment and testing of transformerstransformers

 Routine testRoutine test

 Type testType test

 Increase of old transformers in power gridIncrease of old transformers in power grid



(6)

STANDARDS FOR FACTORY TESTING

Standards

Standards IEC Standards IEC  IEC 60076-1…3IEC 60076-1…3 Standard Standard s s IEIEEEEE  IEEE IEEE C57.12.00 C57.12.00 - - C57.12.90C57.12.90

 IEEE C57.152 (= old IEEE 62)IEEE C57.152 (= old IEEE 62) GOST

GOST

 GOST 1526, GOST 3484, GOST 52719-2007GOST 1526, GOST 3484, GOST 52719-2007

On-S

it

e

T

esti

ng

:

No separate

st

andards

.

use of

same

testing

proc

e

dures,

poss

ible test volt

a

ge re

duct

ion f

or service a

ged

transformers

(7)

P

Poss

ossib

ible T

le Te

est

st``s on p

s on pow

owe

er transf

r transform

orme

ers

rs

Measurements

Measurements of winding resistance of winding resistance

Measurement

Measurement of no-loa of no-load loss d loss and currentand current

Dielectric

Dielectric tests tests

T

Temperature-rise emperature-rise testtest

Determination

Determination of sound levels of sound levels

Me

Measuremeasurement of nt of the harmonithe harmoni cscs of th

of th e no-e no-load currentload current Me

Measureasurement of ment of insuinsu lation rlation r esistanceesistance

Me

Measureasurement of tument of tu rn rrn r atioatio De

Determination termination of of capacapacitancescitances _T_{Tests on}_{ests on on-lo}_{on-lo ad}_ad tap-changers tap-changers

(8)

FACTORY TESTING

-LA

(9)

IMPULSE VOLTAGE TEST OF

POWER TRANSFORMER

ACCORDING

TO

IEC 60076-3, POS. 13-15

IEC 60060-1 2010

(10)

S

Sa

ample of light

mple of light ning

ning impu

impulses

lses

Tail time Tail time Front time Front time 0,9 0,9 0,3 0,3 1,0 1,0 U U B B A A 0,7a 0,7a tt T T11 T T_C_C a a D D C C 0,1a 0,1a a – instant of chopping a – instant of chopping

Full lightning impulse

(11)

 Accuracy is importan Accuracy is important:t:

Correctness of wave shape Correctness of wave shape

 Space is expensive:Space is expensive: Space saving solution Space saving solution

 Time is money:Time is money: Quick test

Quick test setup increasingsetup increasing output of factory

output of factory

Requirements on impulse

vol

(12)

C

Conn

onne

ect

ction

ion P

Poin

oint –

t – T

The

he a

all i

ll in one

n one sol

soluti

ution

on

 Test system consists of only twoTest system consists of only two individual components: individual components: 1) Impulse generator 1) Impulse generator 2) Connection Point 2) Connection Point   HV divider HV divider 

 Chopping gap and Chopping gap and



 Overshoot compensation Overshoot compensation

 Benefits of Connection Point:Benefits of Connection Point:

 Space saving solutionSpace saving solution

 Integrated overshoot compensationIntegrated overshoot compensation

 Only one connection to the test objectOnly one connection to the test object

(13)

S

Spa

pace re

ce reduct

duction

ion usi

using Conne

ng Connecti

ction

on P

Point

oint

Arrangement

Arrangement with Connection with Connection PointPoint

Arrangement

Arrangement with dividerwith divider, overshoot, overshoot

compensation and chopping gap

MOST COMMON LAYOUT

MOST COMMON LAYOUT LAYOUT USING CONNECTION POINTLAYOUT USING CONNECTION POINT

Example: T

Example: Test sest system Uystem U_LI_LI=1800 kV U=1800 kV U_SI_SI= 1150kV= 1150kV

Space

Space requrequirired ed = = 400 400 m² m² Space Space RequiRequired red = = 300 300 m²m²

25

25% space re% space reducductitionon

Test object Test object Divider Divider Chopping Chopping gap gap Overshoot Overshoot Compensat Compensat ion ion Impulse Impulse generator generator Test object Test object Connection Connection point point Impulse Impulse generator generator

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FACTORY TESTING

- APPLIED VOL

(15)

Ap

App

plliied

ed V

Vo

ollttag

age T

e Tes

est

t IEC 60076-3, po

IEC 60076-3, pos

s. 1

. 11

1



 TTransforansfo rmer brmer baseased AC test sysd AC test sys temtem

- continuously duty cycle, high feeding power - continuously duty cycle, high feeding power - high test system costs

- high test system costs



 RResonaesonant nt test system wtest system w ith vith vaariable inductanceriable inductance - perfect sine wave, proven/robust technology

- perfect sine wave, proven/robust technology - less feeding power, less costs

- less feeding power, less costs



 RReesonant sonant test systtest syst eem m witwit h variable freh variable frequencyquency - perfect sine wave, proven/robust technology - perfect sine wave, proven/robust technology

- small components, lowest feeding power, best price - small components, lowest feeding power, best price

Ap

App

plliied

ed v

vo

ollttag

age t

e tes

est

t o

or

r s

sep

epar

arat

ate s

e so

ou

urrc

ce AC w

e AC w iitth

hs

sttan

and v

d vo

ollttag

age

e

test can be pe

(16)

Exampl

Example of Appl

e of Appl ied

ied V

Vol

oltage T

tage Test f

est for

or 12

1200

00 kV

kV

Test of transformer for 800 kV HVDC transmission Test of transformer for 800 kV HVDC transmission at Siemens Nuremberg, Germany

(17)

ADV

ADVANTANTAGESAGES

 CompactCompact

 Easy extendableEasy extendable

 Low power consumptionLow power consumption

 Operates according toOperates according to

IEC >80% of rated voltage IEC >80% of rated voltage

 LowLoweer Ir Investment costnvestment cost

Ap

App

plliied

ed V

Vo

ollttag

age T

e Tes

est

t –

–

V

Variabl

ariable F

e Frequ

requency

ency T

Test Sys

est System

tem

Test system at Siemens Dresden, Germany Test system at Siemens Dresden, Germany

(18)

S

System

ystem C

Conc

once

ept f

pt for A

or Appl

pplied

ied

Voltage Test

1

1 Control Control and and feeding feeding unitunit 2

2 Exciter Exciter transformertransformer 3

3 HV HV reactorreactor 4

4 Blocking Blocking impedanceimpedance 5

5 VVoltage oltage dividerdivider

3 3 5 5 4 4 400V 400V 50 kVA 50 kVA 50/60Hz 50/60Hz LV HV LV HV Transformer Transformer to be tested to be tested

(19)

FACTORY TESTING

-INDU

(20)

Generation of test frequency Generation of test frequency

S

Solu

oluti

tions

ons for

for IIndu

nduced V

ced Volt

olta

age te

ge test

st

Since the test voltage Up for the induced voltage test is often higher than twice the rated Since the test voltage Up for the induced voltage test is often higher than twice the rated voltage, the

voltage, the test frequencytest frequency must bemust be at least doubledat least doubled to avoid over-excitation of the ironto avoid over-excitation of the iron core.

core.

M

(21)

Induc

Induce

ed AC T

d AC Testi

esting

ng

based on Static Frequency Converter

 Different frequencieDifferent frequencies fs for loss mor loss measurement and induced voltageeasurement and induced voltage testing provided by static frequency converter

testing provided by static frequency converter – replaci

– replacing several differeng several different motor-generatont motor-generator-setsr-sets

 Fulfill all demFulfill all demands of standardsands of standards

 EfficientEfficient

 Allows testing of tra Allows testing of transformers >10nsformers >1000 MV00 MVAA

 ExpandableExpandable

 Space-SavingSpace-Saving

 Easy to operate, intrinsically safeEasy to operate, intrinsically safe ADV

(22)

Induc

Induce

ed AC T

d AC Testi

esting

ng

based on Static Frequency Converter

Block diagram of

(23)

Induc

Induce

ed AC T

d AC Testi

esting

ng

based on Static Frequency Converter

Transformer test system for induced

Transformer test system for induced voltage tests, based on static fvoltage tests, based on static frequency converter, type WV 2000-4000/170requency converter, type WV 2000-4000/170

Static frequency Static frequency converter build in converter build in

container

(24)

Induc

Induce

ed AC T

d AC Testi

esting

ng

based on Static Frequency Converter

Static Frequency Converter

built in Container

(25)

THD Value < 5%

Test voltage and current waveform – no-load loss

(26)

Se

Sens

nsit

itive PD

ive PD Me

Measur

asurement

ement

PD Level < 10 pC

(27)

ON-SITE TESTING –

SAME PRINCIPLE

(28)

NO STA

NO STANDARDS NDARDS FOR ON-SITE TESTINGFOR ON-SITE TESTING



 HIGHVOHIGHVOLLT T on-site on-site test test systems systems allow tests allow tests appropriate to appropriate to standardsstandards of factory testing

of factory testing On-Site

On-Site TTests:ests:

 Applie Applied Vold Voltage Ttage Testest

 Induced AC Voltage TestsInduced AC Voltage Tests

 Optional: Impulse TestingOptional: Impulse Testing

HV On-Site Testing

(29)

ON-SITE TESTING –

APPLIED VOL

(30)

 Wide load range of power transformers 5 to 40 nFWide load range of power transformers 5 to 40 nF

 Variable test frequency 40 to 200 HzVariable test frequency 40 to 200 Hz

 Voltage 360 kV – Expandable to 720 kVVoltage 360 kV – Expandable to 720 kV

 Electric current 5 AElectric current 5 A

T

Test Syst

est System f

em for App

or Applilied V

ed Vol

oltage T

tage Test

est

Resonant system with variable frequency Resonant system with variable frequency

Standard 40 foot trailer

(31)

Ap

App

plliied

ed V

Vo

ollttag

age –

e –

P

Pro

rocedur

cedure and T

e and Te

est

st sequenc

sequence

e

 Transportation to siteTransportation to site

 Test arrangement and connection of test object (approx. 50 min)Test arrangement and connection of test object (approx. 50 min)

 Start systeStart system m and enter test parameters (approx. 10 mand enter test parameters (approx. 10 min)in)

 Start automatic test Start automatic test sequencesequence

 Automatic search Automatic search of test frequeof test frequency at 10% of Uncy at 10% of U _test_test

(frequency shall be not less than 80% of rated frequency per IEC) (frequency shall be not less than 80% of rated frequency per IEC)

 Increase the voltage up to UIncrease the voltage up to U _test_test

 WWithstand vithstand voltage testoltage test

 Decrease the voltage up to 0 VDecrease the voltage up to 0 V

(32)

Summ

Summary –

ary – App

Applilied V

ed Vol

oltage T

tage Test

est

 Dielectric test of the main insulation Dielectric test of the main insulation

(between winding and iron core/ tank; between the winding systems) (between winding and iron core/ tank; between the winding systems)

 Test voltage up to 360 kVTest voltage up to 360 kV

with additional reactor up to 720 kV with additional reactor up to 720 kV

 Required power supply: Required power supply: 400 Volt (3~), 40 kVA 400 Volt (3~), 40 kVA

 Only one HV lead to connectOnly one HV lead to connect the transformer under test the transformer under test

(33)

ON-SITE TESTING –

INDU

(34)

Setup for Induced Voltage Test

PD PD 1234 1234 PLC PLC 3 ~ 400V 3 ~ 400V / 50~60 Hz / 50~60 Hz PD measuring PD measuring system system HV capa

HV capacitive compensation unicitive compensation uni t (Option)t (Option)

Transformer Transformer to be tested to be tested 1234 1234 1.

1. FrFreqequeuencncy cony convvererteterr 2.

2. StStepep-u-up trap transnsfoformrmerer 3

3.. HHV fV fiilltteer r 11 4.

4. HV cHV comompepensnsatatioion (n (OpOptition)on) 5.

5. HV HV fifiltlter er 2 (2 (OpOptitionon)) 6.

6. LoLoss mss meaeasusuriring sng syyststemem

1 1 22 33 4 4 5 5 6 6

(35)

Space for Space for accessoiries accessoiries

D

De

esi

sign

gn of

of Mobi

Mobile T

le Te

est

st Sy

Syst

ste

em

m

Static Static frequency frequency converter converter Step-up transformer Step-up transformer Control room Control room HV filter 1 HV filter 1

Power supply cable, Power supply cable, HV connection cable HV connection cable CT’s and VT’s CT’s and VT’s Space for Space for accessories, HV accessories, HV electrodes, etc. electrodes, etc. HV test lead HV test lead

(36)

Induc

Induce

ed v

d vol

oltage –

tage – Proc

Proce

edu

dure and T

re and Te

est

st

S

Sequence (I

equence (IE

EC

C/ I

/ IE

EEE

EE/cus

/custo

tomer

mer sp

spe

eci

cifi

ficati

cation

on))

1.

1. TTraransnsporportatatition on to sto sititee 2.

2. TTest arrest arrangemeangement annt and connectd connection oion of test obf test object (aject (approxpprox. 50 min). 50 min) 3.

3. StaStart syrt systestem and m and ententer ter test pest paraarametmeters ers UU _test_test and f and f _test_test (approx. 10 min) (approx. 10 min)

 Typically: Typically: UU _test_test = 80% of U = 80% of U _{test at factory}_{test at factory}

ff _test_test approx. 2 x f approx. 2 x f _rated_rated (between f(between f _rated_ratedand 200 Hz)and 200 Hz)

 Choose frequency of testChoose frequency of test = f= f _test_test:: a)

a) Factory test Factory test frequency i.e. frequency i.e. 120 Hz,180 120 Hz,180 Hz, etc.Hz, etc. b)

b) Or to minimize Or to minimize the power demand the power demand choose frequency choose frequency to taketo take advantage of variable frequency to reach self compensation advantage of variable frequency to reach self compensation 4.

4. Start Start automatic automatic test test sequencesequence 5.

5. Measure Measure PD at PD at test test voltage voltage levels specifiedlevels specified 6.

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APPL

APPLICATIONICATION

Required for reactive power com

Required for reactive power compensatiopensation during short-circuit tests,n during short-circuit tests, load-loss tests and on-load tap-changer tests

load-loss tests and on-load tap-changer tests SOLUTION

SOLUTION

 Capacitor bank on one trailer or in one 40-foot containerCapacitor bank on one trailer or in one 40-foot container for single phase and small three phase types

for single phase and small three phase types

 Capacitor bank on 2 trailers in Capacitor bank on 2 trailers in four 20-foot containers for largerfour 20-foot containers for larger three phase types (3 containers for capacitors, 1 for measuring three phase types (3 containers for capacitors, 1 for measuring transducers)

transducers)

 Standard types:Standard types:

- up to 250 MVA test objects: 36 kV / 24 MVA, HVCC 24000/36 - up to 250 MVA test objects: 36 kV / 24 MVA, HVCC 24000/36 - up to 500 MVA test objects: 36 kV / 54 MVA, HVCC 54000/36 - up to 500 MVA test objects: 36 kV / 54 MVA, HVCC 54000/36

C

Ca

apacito

pacitor

r Banks

Banks for

for Mobile T

Mobile Transfo

ransform

rme

er

r T

Te

est

st

Systems

(38)

P

Prin

rincipl

ciple

e sketch of m

sketch of mobil

obile

e ca

capa

pacit

citor

or ba

bank

nk

HVCC 24000/36

power measurement: power measurement: current tr

current transformansformer / er / voltage transformvoltage transformerer CT1…CT3: phase current measurement

CT1…CT3: phase current measurement

CT4: protection against unsymmetrical currents CT4: protection against unsymmetrical currents

Compensation units can be connected to form a 3-phase Compensation units can be connected to form a 3-phase

or a powerful single phase capacitor bank or a powerful single phase capacitor bank

HV capacitive HV capacitive compensation units compensation units 40 ft trailer 40 ft trailer cable cabledrumsdrums

(39)

All transformers

up to highest

ratings can be

tested on site

Higher power by

mobile capacitive

compensation

banks is

available

Mobi

Mobille capaci

e capacito

tor

r bank

bank HV

HVCC

CC 24

2400

000/

0/36

36 ins

(40)

 Output voltage: Up to 80 kVOutput voltage: Up to 80 kV

 Output power: 1000 kVA / 620 kWOutput power: 1000 kVA / 620 kW

 Power supply: 400 V (3~)Power supply: 400 V (3~) - 750 k

- 750 kVVA A mains supmains supply orply or - 1200

- 1200 kVkVA A diesel diesel generatorgenerator

 Only 3 HV cables to connectOnly 3 HV cables to connect the transformer under test the transformer under test

 Easy set up:Easy set up:

Within 1 hour ready to test Within 1 hour ready to test

Summ

(41)

EXAMPLES OF TESTED

TRANSFORMERS

(42)

Test of a 500 MVA Single Phase

Trans-fo

former i

rmer in a N

n a Nuc

uclea

lear

r P

Pow

owe

er Sta

r Stati

tion

on

Test of 1phase main transformer with WV 620-1000/80 Test of 1phase main transformer with WV 620-1000/80 Power supply by mobile diesel generator

(43)

Parallel connection of up to 3 test systems (total: 1.9 MW/3 MVA) Parallel connection of up to 3 test systems (total: 1.9 MW/3 MVA)

P

Pa

arall

ralle

el Operatio

l Operation f

n for T

or Te

est

stin

ing

g

up

(44)

S

Sum

ummary

mary

 TTesting power esting power transfortransformers up to mers up to 1200 MV1200 MVAA

 According to IE According to IEC and IEEE standardC and IEEE standardss

 Waveform distWaveform distortion THD < ortion THD < 5%5%

 Partial discharge (PD) noise level < 10 pC (with 2Partial discharge (PD) noise level < 10 pC (with 2ndnd_{HV filter)}_{HV filter)}

 Free adjustable frequency 40 to 200 Hz (self compensation)Free adjustable frequency 40 to 200 Hz (self compensation)

 Modular design allows for future expansionModular design allows for future expansion

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