8/11/2019 Lecture Hv Testing

1/22

TKE474

~ ~

Hi hVolta e

Testin

06/01/2011

8/11/2019 Lecture Hv Testing

2/22

Dielectric/insulationmaterialshouldpossess

goo

insu ating

properties

over

a

wi e

range

ofoperationparameters.

HighVoltagetestsareappliedtodetermine

designrequirements

Toensure

t at

t e

e ectrica

equipments

arecapableofwithstandingthe

06/01/2011

overvo tages t ataremetwit inservice.

8/11/2019 Lecture Hv Testing

3/22

Coversbasicrequirementsproceduresfor

testing

on

severa

e ectrica

apparatus.

Normally,highvoltage(HV)testingistoinvestigatet einsu ationper ormance

06/01/2011

8/11/2019 Lecture Hv Testing

4/22

Forcustomer:

To

demonstrate

that

the

apparatus

h m tth r nt ifi ti n f i l tri strength.

Formanufacturer:Tocheckonthedesign,adeterminationofthestrengthofthematerialsand

agu e

o

e

eve opmen

o

e erequ pmen .

06/01/2011

8/11/2019 Lecture Hv Testing

5/22

06/01/2011

8/11/2019 Lecture Hv Testing

6/22

C assi ication

o

Tests

Madeby

the

manufacturer

on

every

finished

pieceofproducttomakesuchthatitfulfillsthespecifications.Itcanbepartofthe

manufacturingprocess.

o xamp eso ou ne es :Powerfrequencyovervoltagetestforinsulation,

. .

withstandtest.Thisisperformedoneveryunitatthemanufacturersfactor and ossibleafter

06/01/2011

receiptoftheunitbythepurchaser.

8/11/2019 Lecture Hv Testing

7/22

II.TypeTest Performedoneachtypeofinsulatorsbeforetheir

demonstratethe

performance

characteristics

meetin theintendeda lication

Thesetests

need

not

be

repeated

unless

changes

are

ma e n e es gno epro uc

o ExamplesofTypetest: Dr li htnin im ulsevolta ewithstandtestWet

switching

impulse

voltage

withstand

test

WetACvoltagewithstandtest

06/01/2011

8/11/2019 Lecture Hv Testing

8/22

III.Sample/SpecialTest This testwhichisperformedtocheckinsulation

o Exam lesofSam le/S ecialtest: Soundleveloftransformer

06/01/2011

8/11/2019 Lecture Hv Testing

9/22

StandardonHVistheguidanceontheprinciplesan co eo prac ce nvo v nga genera on,

procedures,installation,

manufactures,

testing

and

calibration. Coveringtherequirementsregardingdesign,quality

ofmaterial,

installation,

etc.

rov emax mumgu ancetoprotectaga nsta thedamagingeffectofhighvoltage.

06/01/2011

8/11/2019 Lecture Hv Testing

10/22

06/01/2011

8/11/2019 Lecture Hv Testing

11/22

I.PowerFrequencyDryandWetFlashoverTests

06/01/2011

8/11/2019 Lecture Hv Testing

12/22

06/01/2011

8/11/2019 Lecture Hv Testing

13/22

06/01/2011

8/11/2019 Lecture Hv Testing

14/22

II.

T

wi h

Im l

V l

06/01/2011

8/11/2019 Lecture Hv Testing

15/22

Im l

Wi h n

V l

T

06/01/2011

8/11/2019 Lecture Hv Testing

16/22

Im l

Fl h v r

T

06/01/2011

8/11/2019 Lecture Hv Testing

17/22

BasicSwitchingImpulseInsulationLevel(BSL)

The

BSLis

the

electrical

strength

of

insulation

expressedintermsofthecrestvalueofastandardsw tc ng mpu se. estat st ca , nsu at onexhibitsa90%probabilityofwithstandsa10%

.

. ,

BSLiscalledtheswitchingimpulsewithstandvolta e.

06/01/2011

8/11/2019 Lecture Hv Testing

18/22

BasicLightningImpulseInsulationLevel(BIL)

The

BILor

basic

lightning

impulse

insulation

level

is

ee ec r ca s reng o nsu a onexpresse n ermsofthecrestvalueofthestandardlightningimpulse.

06/01/2011

8/11/2019 Lecture Hv Testing

19/22

Impulse

Insulation

Strength

Insulationstrength

is

expressed

in

terms

of

conventionalorstatisticalBILsandBSLs.Foreveryapplicationofanimpulsehavingthe

standardwaveshape and

whose

crest

is

equal

to

the

BILorBSL,t epro a i ityo a as overor ai ureis10%.

definedasthecriticalflashovervoltageorcriticalflashover CFO .

06/01/2011

8/11/2019 Lecture Hv Testing

20/22

Impulse

Insulation

Strength

06/01/2011

8/11/2019 Lecture Hv Testing

21/22

Impu se

Insu ation

Strengt

usuallystatistically

described

by

aCFOvoltage

at

whichtheinsulationexhibitsa50%probabilityofflashoverandbyastandarddeviation whichis

approximately

5%

of

the

CFO(IEEE

Std.

62.22,

1997)

06/01/2011

8/11/2019 Lecture Hv Testing

22/22

Standard withstand voltage for 15kV