ARYA COLLEGE OF ENGINEERING & RESEARCH CENTRE KUKAS-JAIPUR
8EE7 HIGH VOLTAGE ENGINEERING LAB Practical No:-1
Objective:Study fit!"ti#$ "$d t!%t%$t #f t!"$'f#!%! #i S(N# Vi)" *u%'ti#$' +t# ,% "$'%!%d i$ t.% L", fi%/ ( 1.
What are the use of trasformer oil? For insulation and cooling.
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What is the relative permittyvity of tranformer oil? 2.2-2.3.
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What is the breakdown strength at 2 degree 2.! mm 1 min. of transformer oil ? 12kv"mm. What is the specific gravity at 2 degree cent. of tansformer oil
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%$Write Wr ite the ma&imum permissible water content in tranformer oil . ! ppm
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Which dielectrics are used mostly? (etroleum oils.
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What is the important properties of dielectric? *ielectric strength+electri strength+electrical cal coductivity
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Which factor affect the dieletric strength (resence of some water droplet and fibrous impurities.
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Which type of filters are used? Filter press and hard filter papers are more suitable.
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,ive the name of adsorbing agent? 1 fuller earth 2.silisa gel 3.molecular sieves.
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What is test cell?. n which oil is poured in a container.
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What is electrostatic filter? he oil to treatedis passd between the two elctrodes placed in a container.
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What is centrifugal method? his method is helpful in patially e&tating solid impurites and free water.
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What should be the pressure in filtraton? ,reater than .1 torr.
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What is /asching-ring? 0 large surface where oil is distributed.
ARYA COLLEGE OF ENGINEERING & RESEARCH CENTRE KUKAS-JAIPUR
8EE7 HIGH VOLTAGE ENGINEERING LAB Practical No:-2
Objective:Determine dielectric strength of transformer oil S(N# Vi)" *u%'ti#$' +t# ,% "$'%!%d i$ t.% L", fi%/ ( What is the dielectric strength of transformers oil? 0ns. he dielectric strength of new unrated oil is 1. 12"m/45 6 after treatment it should be 72#"m/45. What is the function of transformer oil? ainly for cooling 6 in solution purpose. 8n larger 2. transformer the buchol9 relay utili9es the oil as trip mechanism for internal fault condition
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1. 11.
12.
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What is dielectric constant? he dielectric constant is the ratio of the permittivity of a sub stance to permitting of free space . What is the colour of :-mer oil? he colour of &-mer oil is grey. What is electrical conductivity? t is the reciprocal of electrical resistivity. t is also called specific conductance and measures a martial;s ability to conduct an current. What is the value of breakdown of dielectric li pure grain alcohol . What is threshold condition?
What do you mean by avalanche in li
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,iven the internal dimension of container used in this test? *imension is !!ma&. 1mm. What is the acceptable value of voltage for #mm gap length in sphere? he value strata from #> of the rapidly applied voltage.
ARYA COLLEGE OF ENGINEERING & RESEARCH CENTRE KUKAS-JAIPUR
8EE7 HIGH VOLTAGE ENGINEERING LAB Practical No:-3
Objective:Determine capacitance and dielectric loss of an insulating material using Schering bridge. S(N# Vi)" *u%'ti#$' +t# ,% "$'%!%d i$ t.% L", fi%/ ( 1.
4chering bridge is used for measurement of? Aapacitance
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Fault location in an B cable is done by? (artial discharge scanning test
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ost important tests conducted on isolators are? 4hort circuit test
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he charge associated with patial discharges in electrical apparatus will be? (ico coloumbs.
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For B cable insulation+ the material used are? (aper oil insulation.
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he insulation used in high voltage circuit breakers of large power ratings? 4F'
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,as insulation is now a days used in?
Aircuit breakers. $.
n (d detectors partial discharge are displayed? @uilt in A/8 with elliptic time base.
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(artial discharge detector is a device that measures or detects? 0 partial discharge
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Aorona discharge is? (artial discharge around a high voltage conductor.
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Wagner;s eath is used with schering-bridge for? Aliminating stray capacitance and coupling.
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he power supply used in resistivity measurement is? ! to 2v
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Coss of charge method is used to determine? nsulation resistance.
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For resistivity and dielectric constant measurement the electrode system used is? hree electrode.
ARYA COLLEGE OF ENGINEERING & RESEARCH CENTRE KUKAS-JAIPUR
8EE7 HIGH VOLTAGE ENGINEERING LAB Practical No:-4
Objective:4tudy solid dielectrics used in power apparatus S(N# Vi)" *u%'ti#$' +t# ,% "$'%!%d i$ t.% L", fi%/ ( Dlectrical conduction in gases was first studied by? 1. ownsend 4F-' is a? 2. Dlectronegative ,as inimum 4parking (otential of 0ir s? 3. 32! he /e
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he break down strength of mineral oil is about? 3-# =v"mm *ielectric constant of mineral oil is? 2.2-2.# a&imum dielectric strength obtain with pure li
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(aper insulators is mainly used in? Aabals and capacitors.
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he usual mechanism of breakdown in solid dielectrics? hermal @reakdown
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hermal classification of insulating material is done for? 4olids
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@reakdown due to internal discharge develops? n long duration of day
ARYA COLLEGE OF ENGINEERING & RESEARCH CENTRE KUKAS-JAIPUR
8EE7 HIGH VOLTAGE ENGINEERING LAB Practical No:-5
Objective:Study "$d "00i1"ti#$ #f i$'u"ti2 "tt%!i"( S(N# Vi)" *u%'ti#$' +t# ,% "$'%!%d i$ t.% L", fi%/ ( 1.
What is insulation? o satisfactory operation of cables.
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What is main re
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,ive the name of insulating materials? ,lass+porcelain+steatite etc. What is insulator?
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nsulator are useed to provide high resistance between line and live part. What is the re
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1.temperature insulation.
sesivity
2.mechnical
strength
3.electrical
What is cause of insulator failure? 1.flash over 2.cracking of insulator 3.porosity of material etc. ,ive the name of methods of improving string efficiency?
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1.by using longer cross arm 2.by grading the insulator 3.by using guard ing What is the use of stay insulators? n case of low voltage lines. What is the advantage of suspension type insulator?
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f any one disc of is damaged+the hole string the whole string does not becomes useless. What is the string efficiency of B lines? $>.
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What is the meaning of 1> string efficiency? ero potential across each disc.
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Where are used generally pos type insulator? n any voltage level hv+ehv.
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What is the use of guard ring? D
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Whch type of insulator are used for 132kv lines?
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*isc type. What is corona? Aomplete breakdown of air
ARYA COLLEGE OF ENGINEERING & RESEARCH CENTRE KUKAS-JAIPUR
8EE7 HIGH VOLTAGE ENGINEERING LAB Practical No:-6
Objective:4tudy direct testing and indirect testing of circuit breakers S(N# Vi)" *u%'ti#$' +t# ,% "$'%!%d i$ t.% L", fi%/ ( What is a circuit breaker? t is a piece of e
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Aircuit breaker testing is used to test to both the performance of individual switching mechanism and the timing of the overall tripping system. Which type of insulating material used in circuit breaker? hese are ceramic+
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Bow many type of test performing on circuit breaker? *irect test+ indirect test+ synthetic test . For controlling rate of restricting voltage what is used? t can be achieved by ioni9ed partied in space between contacts to recombine into neutral molecules. 4weeping the ioni9ed particles away and replacing by un-ioni9ed particles. What is the value of test voltage of circuit breaker? he circuit breaker value of the rated value of the ransmission line. What is system nominal voltage? t is the rated voltage of an electric e
ARYA COLLEGE OF ENGINEERING & RESEARCH CENTRE KUKAS-JAIPUR
8EE7 HIGH VOLTAGE ENGINEERING LAB Practical No:-7
Objective:Study .i2. )#t"2% t%'ti$2 #f %%1t!i1" %3u0%$t4i$% i$'u"t#!51",%'5,u'.i$250#%! 1"01it#! "$d 0#%! t!"$'f#!%!( S(N# Vi)" *u%'ti#$' +t# ,% "$'%!%d i$ t.% L", fi%/ ( What is insulator? 1.
2.
nsulator are useed to provide high resistance between line and live part. What is reduced by bundle conductor? 4urface electric stress of conductor
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What is the effect of corona? ncreased energy losses.
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When the inductance of transmission line is minimum? ,* is low and ,/ is high.
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What is used for full load compensation in lines? 4hunt capacitor
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What is used for no load compensation for B lines? 4hunt reactor
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What is the advantage of underground cables? he voltage drop is less.
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Whai is the advantage of overhead lines? he conductor are less e&pansive.
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What are the main part of underground cables? Aore+insulation+metalic sheath+bedding etc.
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What is main properties of insulatig material for cables? Bigh resistivity+high dielectric strength+low permittivity etc.
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What is C cables? hese are used for voltage below 1 kv.
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What is synchronous condensor? 4ynchrnous motar.
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What is power capacitor? o compensate the reactive power.
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Why capacitor are used? mprove voltage regulation.
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What is the surge impedance value for cables? Cower than those of over head lines.
ARYA COLLEGE OF ENGINEERING & RESEARCH CENTRE KUKAS-JAIPUR
8EE7 HIGH VOLTAGE ENGINEERING LAB Practical No:-8
Objective:6%'i2$ "$ EHV t!"$'i''i#$ i$%( S(N# Vi)" *u%'ti#$' +t# ,% "$'%!%d i$ t.% L", fi%/
( 1.
What is DB transmission line? For operating voltage is #-)'! kv.
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What is advantage of DB? For increase power transfer capacity.
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8n which basis of conductor of DB line is selected? Aorona and / perfomance
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What is the range of fre
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What is use of bundle conductor? (ower loss due to corona
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What is the use of series capacitor in transmission lines? Aopensate the voltage drop.
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What is booster? 0 series wound dc generator driven by dc shunt generator.
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What is the use of booster? Aompensate for voltage drop.
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What is use of series capacitor in disribution lines . o provide reactive power compensation
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Why high transmission line are transposed? (hase voltage imbalances can be minimi9ed What is need of transposed tranmisson line? (revent interfacing with neighbouring telephone lines. 8n which depends the breakdown voltage? (resence of moisture+operating temprature etc. 8n which factor corona losses depends? *iameter of conductor. Where is skin effect e&ist? 0c transmission only. n suspension type which insulator having high voltage? a&imum across the lowest disc.
