Page 32 - ECLECTIC MARCH-2022 INSIDE PAGES_p2.indd
P. 32
surement and Online Measurement. Relevant field trials in insulation from the outside. An erosion of the insulation causes an
ifferent suspected cable sections will be continued which would help increase in discharge which further increases level of discharge activity
o minimize Underground cable faults. and this cascading damage to cable insulation finally results in the
breakdown of cable insulation.
Thus, online measurement of Partial Discharge in Cables is highly
aults on underground power cables are almost always disruptive and required to arrest unplanned outages due to fault in Underground
ostly to fix. So, there’s a very big incentive to minimise the risk of such (UG) Cables.
aults occurring. One of the most effective ways of doing this is to use Technologies that can be implemented in locating Partial Discharge in
artial discharge (PD) testing and mapping, partial discharge activity is UG Cables to prevent unplanned outages are Spot Measurement and
n indication of incipient insulation faults and is widely regarded as Online Measurement.
ne of the best ‘early warning’ indicators of deterioration in medium
nd high voltagoep ipnsourltautnioitni.e s for condition assessment. The effects of
Cable Insulation Degradation are exponential in natureII. PRPORCEOSCS IENSVOSLVINEDVOLVED
INTRODUCuTnIOtilN catastrophic failure occurs. Regular PD testing
M&aeuEebwSrdiPlCee i— iudsn3.m U3pWju knovseVdoit n eslmtnttraaeigagnrrtttoflnetwoergeanue uscogdfnotanar iifFdbnnkdcuil ePt- geeXpsumdlsaeLdr oiPrehr scoTvstdEahrriti ,viaculC aayescelnanl t ostibDcdgl hmctlol oeoeriaimnsepssu bpc e.patb lrh ehtrrdethaeisee‐issadrl edoftptgasilcnwry ecaoncottidovtetfet hrihpee dXythfdeh;eLde aeP(scas2bf Etdetu)us ea esriCssn tiftefatnehsorfbctoe uat3ftlmrohe ll3plserediom nikdsraianiv Vnlm—tietafdosesi flritctanPeihygr“ IacaiLaandlc Cte3tsya i:3u ocb of(karo1nllVadenr).n sPcb1teDoe”
bolmesmuisssiniogniOngna lbgiunatien nsMot tco yanebittl eoernfiaenurggltiTsz.eeAdc;nh adnn,idcq ou(n3e)ss iadgeerde d—in int‐hserlvigichet forf the
ome period ofifn tainmceia. lTihmespea cdtifofefreantt yppeicriaoldcsa obfl ethfaeuirl tl,ifiet ’sprinovsuidrea nce
peMpgror.arSdtuoanutiimotinea lsay rfawoe rRee cxlolopywno;dnoCiertoitnonhtndiab iatlu isionsyne innsMasgtm.ounereint otu.rn Titnhigle c Caetfeaflelsctrtos pohf iCca fbalielu Irnes ouclactuiorsn.
egular PD testing on in‐service cables provides useful data that can
e trended or compared with data from similar cables to flag up
hgumeilnyahas aslrtntluley lg dfoaorouetepfic rnssetemu grhtdal the tasiioaf n n iffitndgti n n“aiennescdui arfalu nirmtchepe”ar ca itng aoviefn sast titg ycapatibicolaenl .f cPaaDubl lttese .sf aAtiunnldgt, , i sict o’usnn isdniosduuerbraetnNedcdo ei lnoy fw ttFhheaeeulll ts
nogr tah p bouteynitniagl . 140
120 FFigigu 2re: C2a:bClea PbDle LPoDcaLtoiocant TioenchTenciqhuneiqs ues
everal reasons
essive heat or 100
e sheath. All of 80
the insulated 60
nally designed. 40 Identification of Suspected 33kV Cables
ncluding short 20
ive heating of 0 1. HIFdCenTtifPicRatPioDn oPf aSuttspeercntead n33dkVW Caabvleesf orms collected during of the cable an
roIduetnitnifeicastitoen oinf Ssupsepeccttieodn 33kV Cables dofir tehcetl yc afbrolem a nth
and sheathing FY 15‐16 FY 16‐17 FY 17‐18 FY 18‐19 FY 19‐20 dthiree rcetlfyle fcrtoiomn tah
om an external Fig 1: Cable Fault Statistics over last 5 years 2. C11a..blHHienFFsCCpSTTee cPPtcRRiotPPniDDo PPnaastttteesrrenn laaenncddt WWedaavveeoffoonrrmmtssh ccooelllleebccttaeeddsi ddsuurroiinnfgg rrrooeuupttiienneet isstiiittveee tohpee nre. flection a
ent flow in the fa2i.lurCineasbphleic sSttieoocntr iy ons selected on the basis of repetitive failure history Tohpe np. osition o
oaded and/or Figure 1: Cable Fault Statistics over last 5 years Tdheete rpmosiniteiodn boy
2. Cable Sections selected on the basis of repetitive failure history pdeartteiraml dinisecdh abryg
A discharge spark erodes the insulation from within through its heat pthairst itaelc dhinsciqhuaerg
and ionization. If occurring on the surface, the discharge also causes tmhuiss t ebceh noipqeune s
mbeu astp pbleie odp ienn a sc
ect any 33kV Awthdiethi bs acrethmaakodrsgopwheenr soicpf oaaxirry kgmeonel etrocou fdloeersm sin ottozho nenaes cainenndstu aoltxamytgoioesnpn hwehrfiricco hnm ictoromgwbeiinnt hetosi n be applied in ac
ble fault ‐ Spot tshuiifnnroroscfraumruelca agnetsihieo,tr nitinc hi ftdoresoixsmicddhh eiatse.h rcTagehhet e oaw uanrhtginsitcireddhice f a.uo ilrxAostinodhn eeei rczfr ioaaonrstucmiiroosesnea n nsso.eitfstr I ihtlcfeh evaeoec iblicn dorsc,f eu wudlaaihrsktriciciodhnhnao g erwcgraeouon dasencestosi v tfthiathaney ier
field trials in
ich would help
disruptive and matTbamonhreldueoa skct,s hdpuoiosnlhw elceinsnar esoic icfnam cdtaeoionbaxglsey un digrnaaeesmsmuncaleaegntenitto otntoo.f o fcoPxaarybrmtgleiae li nnoDszuiswolcahnthiaoeirncg ehaf innincad lolCyma arbtelbmesusin lotiesss spihnih gwthehlireyti hc
he risk of such ancir(TtUeierdqoGc,uh)g inwCreoeadlnhbo ligetctiosoeh .s a ftreohrerarosmtt cd auennns ipbtlreati nhcimneoepdxlie niomdsueeutna.ltagTeethdsio eidnnu nloeifc trtarooitci mnfagou Pxtltahi drietneia Ulof Donuidrstmecshrigdasrreognue.in tAirdni nc
g this is to use ewrOUhoGniscl iiCnohaenb fMuleoersfta thstouhe rpreermeinivenecnsnrtuet. ulaanstpeiolsannlencevdae uol oustefasdgeiassn cahriena Scrpgroeeta Masceetaiisvnuirtedymiasecnnhtd aatnrhgdi es
arge activity is
y regarded as
on in medium
caIsI.caPdRinOgCEdSaSmINaVgOeLVtEoDcable insulation finally results in the
and PILC old breakdown of cable insulation.
oints in a 33kV
Fig 4: PD Map
Thus, online measurement of Partial Discharge in Cables
Fciagb 4le: P(XD AMxiasp)
eir lifecycle: (1) is highly required to arrest unplanned outages due to cable (X Axis)
ed — ready for fault in Underground (UG) Cables. This problem is
in‐service for eThnidss porfo bthleem c aisb
ir life provide Aenftdesr eoaf cthh eca cpatb
able Insulation tAimfteer edaeclahy c aopf tt
failure occurs. Technologies that can be implemented in locating Partial Fig 3: PD Patterns detected at some Underground 33kV Cables tpilmacee d ealta yt hoef et
plaarcteiadl daits cthea reg
data that can Discharge in UG Cables to prevent unplanned outages FigFiug 3re: PD3 :PaPttDernPs adtettecrtnesd adt esotemcet eUdndeartgrsoounmd e33UkVn Cdaeblregsr ound pbya rtpiarilo dr isrcehmarog
les to flag up 33OknV thCea bbasleiss of the above criterion, field trial of the following 33kV bcayp tpurrioerd rpeamrtoia
ndoubtedly the are Spot Measurement and Online Measurement. captured partia
Osenc tihoen sb adsoins eo fa th seit ea.b ove criterion, field trial of the following 33kV
sidered in the sections done at site. B. Identifica
insurance well DB.iscIhdaerngteifiScoa
Sl. Suspected 33 kV Cable Sections EDffiiscciehnacryg oef Stho
Fig 2: Cable PD Location Techniques Edfifficeireenncty p oafr tiha
NSlo. . Suspected 33 kV Cable Sections dloifcfaetrieont o pfa trhteia
32 N1 o. Botanical GIS – Belilious Park GIS dloisccahtiaorng eo flo tchaet
21 Baoltlayn GicISa l‐ G BIeSl u–r B GeIlSil ious Park GIS doinsec hoarr mgeo lroec apta
32 KBRalSly ‐ GRIiStc ‐h Biee GluIrS G FI2S ionn teh oer o mpeonre e pnad
43 KPRriSn c‐e Rpit Scth GieI SG ‐IS K Fid2d erpore GIS F2 ionu theer souprefanc en Pd
45 BPrBiDnc Beapg S Gt IGSI S‐ S‐ tKraidndde Srpoourteh GIS F2
56 KBRBSD ‐B Naeg wG IBSa ‐l lSytgruanngde S (oEu) tDh/ GS ITS3
ifferent suspected cable sections will be continued which would help increase in discharge which further increases level of discharge activity
o minimize Underground cable faults. and this cascading damage to cable insulation finally results in the
breakdown of cable insulation.
Thus, online measurement of Partial Discharge in Cables is highly
aults on underground power cables are almost always disruptive and required to arrest unplanned outages due to fault in Underground
ostly to fix. So, there’s a very big incentive to minimise the risk of such (UG) Cables.
aults occurring. One of the most effective ways of doing this is to use Technologies that can be implemented in locating Partial Discharge in
artial discharge (PD) testing and mapping, partial discharge activity is UG Cables to prevent unplanned outages are Spot Measurement and
n indication of incipient insulation faults and is widely regarded as Online Measurement.
ne of the best ‘early warning’ indicators of deterioration in medium
nd high voltagoep ipnsourltautnioitni.e s for condition assessment. The effects of
Cable Insulation Degradation are exponential in natureII. PRPORCEOSCS IENSVOSLVINEDVOLVED
INTRODUCuTnIOtilN catastrophic failure occurs. Regular PD testing
M&aeuEebwSrdiPlCee i— iudsn3.m U3pWju knovseVdoit n eslmtnttraaeigagnrrtttoflnetwoergeanue uscogdfnotanar iifFdbnnkdcuil ePt- geeXpsumdlsaeLdr oiPrehr scoTvstdEahrriti ,viaculC aayescelnanl t ostibDcdgl hmctlol oeoeriaimnsepssu bpc e.patb lrh ehtrrdethaeisee‐issadrl edoftptgasilcnwry ecaoncottidovtetfet hrihpee dXythfdeh;eLde aeP(scas2bf Etdetu)us ea esriCssn tiftefatnehsorfbctoe uat3ftlmrohe ll3plserediom nikdsraianiv Vnlm—tietafdosesi flritctanPeihygr“ IacaiLaandlc Cte3tsya i:3u ocb of(karo1nllVadenr).n sPcb1teDoe”
bolmesmuisssiniogniOngna lbgiunatien nsMot tco yanebittl eoernfiaenurggltiTsz.eeAdc;nh adnn,idcq ou(n3e)ss iadgeerde d—in int‐hserlvigichet forf the
ome period ofifn tainmceia. lTihmespea cdtifofefreantt yppeicriaoldcsa obfl ethfaeuirl tl,ifiet ’sprinovsuidrea nce
peMpgror.arSdtuoanutiimotinea lsay rfawoe rRee cxlolopywno;dnoCiertoitnonhtndiab iatlu isionsyne innsMasgtm.ounereint otu.rn Titnhigle c Caetfeaflelsctrtos pohf iCca fbalielu Irnes ouclactuiorsn.
egular PD testing on in‐service cables provides useful data that can
e trended or compared with data from similar cables to flag up
hgumeilnyahas aslrtntluley lg dfoaorouetepfic rnssetemu grhtdal the tasiioaf n n iffitndgti n n“aiennescdui arfalu nirmtchepe”ar ca itng aoviefn sast titg ycapatibicolaenl .f cPaaDubl lttese .sf aAtiunnldgt, , i sict o’usnn isdniosduuerbraetnNedcdo ei lnoy fw ttFhheaeeulll ts
nogr tah p bouteynitniagl . 140
120 FFigigu 2re: C2a:bClea PbDle LPoDcaLtoiocant TioenchTenciqhuneiqs ues
everal reasons
essive heat or 100
e sheath. All of 80
the insulated 60
nally designed. 40 Identification of Suspected 33kV Cables
ncluding short 20
ive heating of 0 1. HIFdCenTtifPicRatPioDn oPf aSuttspeercntead n33dkVW Caabvleesf orms collected during of the cable an
roIduetnitnifeicastitoen oinf Ssupsepeccttieodn 33kV Cables dofir tehcetl yc afbrolem a nth
and sheathing FY 15‐16 FY 16‐17 FY 17‐18 FY 18‐19 FY 19‐20 dthiree rcetlfyle fcrtoiomn tah
om an external Fig 1: Cable Fault Statistics over last 5 years 2. C11a..blHHienFFsCCpSTTee cPPtcRRiotPPniDDo PPnaastttteesrrenn laaenncddt WWedaavveeoffoonrrmmtssh ccooelllleebccttaeeddsi ddsuurroiinnfgg rrrooeuupttiienneet isstiiittveee tohpee nre. flection a
ent flow in the fa2i.lurCineasbphleic sSttieoocntr iy ons selected on the basis of repetitive failure history Tohpe np. osition o
oaded and/or Figure 1: Cable Fault Statistics over last 5 years Tdheete rpmosiniteiodn boy
2. Cable Sections selected on the basis of repetitive failure history pdeartteiraml dinisecdh abryg
A discharge spark erodes the insulation from within through its heat pthairst itaelc dhinsciqhuaerg
and ionization. If occurring on the surface, the discharge also causes tmhuiss t ebceh noipqeune s
mbeu astp pbleie odp ienn a sc
ect any 33kV Awthdiethi bs acrethmaakodrsgopwheenr soicpf oaaxirry kgmeonel etrocou fdloeersm sin ottozho nenaes cainenndstu aoltxamytgoioesnpn hwehrfiricco hnm ictoromgwbeiinnt hetosi n be applied in ac
ble fault ‐ Spot tshuiifnnroroscfraumruelca agnetsihieo,tr nitinc hi ftdoresoixsmicddhh eiatse.h rcTagehhet e oaw uanrhtginsitcireddhice f a.uo ilrxAostinodhn eeei rczfr ioaaonrstucmiiroosesnea n nsso.eitfstr I ihtlcfeh evaeoec iblicn dorsc,f eu wudlaaihrsktriciciodhnhnao g erwcgraeouon dasencestosi v tfthiathaney ier
field trials in
ich would help
disruptive and matTbamonhreldueoa skct,s hdpuoiosnlhw elceinsnar esoic icfnam cdtaeoionbaxglsey un digrnaaeesmsmuncaleaegntenitto otntoo.f o fcoPxaarybrmtgleiae li nnoDszuiswolcahnthiaoeirncg ehaf innincad lolCyma arbtelbmesusin lotiesss spihnih gwthehlireyti hc
he risk of such ancir(TtUeierdqoGc,uh)g inwCreoeadlnhbo ligetctiosoeh .s a ftreohrerarosmtt cd auennns ipbtlreati nhcimneoepdxlie niomdsueeutna.ltagTeethdsio eidnnu nloeifc trtarooitci mnfagou Pxtltahi drietneia Ulof Donuidrstmecshrigdasrreognue.in tAirdni nc
g this is to use ewrOUhoGniscl iiCnohaenb fMuleoersfta thstouhe rpreermeinivenecnsnrtuet. ulaanstpeiolsannlencevdae uol oustefasdgeiassn cahriena Scrpgroeeta Masceetaiisvnuirtedymiasecnnhtd aatnrhgdi es
arge activity is
y regarded as
on in medium
caIsI.caPdRinOgCEdSaSmINaVgOeLVtEoDcable insulation finally results in the
and PILC old breakdown of cable insulation.
oints in a 33kV
Fig 4: PD Map
Thus, online measurement of Partial Discharge in Cables
Fciagb 4le: P(XD AMxiasp)
eir lifecycle: (1) is highly required to arrest unplanned outages due to cable (X Axis)
ed — ready for fault in Underground (UG) Cables. This problem is
in‐service for eThnidss porfo bthleem c aisb
ir life provide Aenftdesr eoaf cthh eca cpatb
able Insulation tAimfteer edaeclahy c aopf tt
failure occurs. Technologies that can be implemented in locating Partial Fig 3: PD Patterns detected at some Underground 33kV Cables tpilmacee d ealta yt hoef et
plaarcteiadl daits cthea reg
data that can Discharge in UG Cables to prevent unplanned outages FigFiug 3re: PD3 :PaPttDernPs adtettecrtnesd adt esotemcet eUdndeartgrsoounmd e33UkVn Cdaeblregsr ound pbya rtpiarilo dr isrcehmarog
les to flag up 33OknV thCea bbasleiss of the above criterion, field trial of the following 33kV bcayp tpurrioerd rpeamrtoia
ndoubtedly the are Spot Measurement and Online Measurement. captured partia
Osenc tihoen sb adsoins eo fa th seit ea.b ove criterion, field trial of the following 33kV
sidered in the sections done at site. B. Identifica
insurance well DB.iscIhdaerngteifiScoa
Sl. Suspected 33 kV Cable Sections EDffiiscciehnacryg oef Stho
Fig 2: Cable PD Location Techniques Edfifficeireenncty p oafr tiha
NSlo. . Suspected 33 kV Cable Sections dloifcfaetrieont o pfa trhteia
32 N1 o. Botanical GIS – Belilious Park GIS dloisccahtiaorng eo flo tchaet
21 Baoltlayn GicISa l‐ G BIeSl u–r B GeIlSil ious Park GIS doinsec hoarr mgeo lroec apta
32 KBRalSly ‐ GRIiStc ‐h Biee GluIrS G FI2S ionn teh oer o mpeonre e pnad
43 KPRriSn c‐e Rpit Scth GieI SG ‐IS K Fid2d erpore GIS F2 ionu theer souprefanc en Pd
45 BPrBiDnc Beapg S Gt IGSI S‐ S‐ tKraidndde Srpoourteh GIS F2
56 KBRBSD ‐B Naeg wG IBSa ‐l lSytgruanngde S (oEu) tDh/ GS ITS3
