Ukusuka kuhlelo ukuya kwimodi yocingo, eyona ngcaciso ibanzi ye-grounding transformer

I-6kV, 10kV kunye ne-35kV iigridi zamandla kwisixokelelwano samandla ngokuqhelekileyo zamkela imo yokusebenza engathathi hlangothi. Icala eliphantsi kwe-voltage ye-transformer ephambili kwigridi yamandla ngokuqhelekileyo ixhunywe ngendlela enxantathu, kwaye akukho ndawo engathathi hlangothi enokuthi isekelwe. Xa impazamo yenqanaba elilodwa lesiseko lenzeka kwinkqubo engathathi hlangothi, unxantathu wombane womgca uhlala ulinganisa. Inkqubo yamandla inokuqhubeka nokubonelela amandla kubasebenzisi kwi-1 ukuya kwiiyure ze-2, kwaye i-capacitive current incinci (ngaphantsi kwe-10A), engayi kubangela i-arc intermittent. Ezinye iimpazamo zexeshana ezisisiseko zinokunyamalala ngokuzenzekelayo, nto leyo esebenza kakhulu ekuphuculeni ukuthembeka konikezelo lwamandla kunye nokunciphisa iingozi zokumka kombane. Nangona kunjalo, kunye nokwandiswa okuqhubekayo kwegridi yamandla asezidolophini kunye nokunyuka okuqhubekayo kwemigca yentambo ephumayo, i-capacitive current yenkqubo emhlabeni iyanda ngokukhawuleza, kwaye i-capacitive current equkuqela kwindawo yempazamo emva kokumiswa kwesigaba esinye sikhulu (ngaphezulu kune 10A).

I-arc akukho lula ukuyicima, kulula ukuyivuselela i-ferromagnetic resonance overvoltage kwaye ivelise i-intermittent arc light grounding overvoltage, enokubangela umonakalo wokugquma, ihambe emgceni kwaye yandise ingozi.

Ngokukodwa:

Ukuphela okungapheliyo kunye nolawulo lwenqanaba elinye lokumisa i-arc kuya kuvelisa i-arc grounding over-voltage ene-amplitude ukuya kuthi ga kwi-4U (U lixabiso lencopho yombane wesigaba esiqhelekileyo) okanye ixesha elingaphezulu nelide, eliya kubangela umonakalo omkhulu ekufakweni kwezixhobo zombane. kwaye ibangele ukuphuka kwi-insulation ebuthathaka; Banga ilahleko enkulu.

Ukuqhawulwa komoya okubangelwa yi-arc eqhubekayo kutshabalalisa i-insulation yomoya ojikelezayo kwaye ixhomekeke kwisigaba ukuya kwisigaba sesiphaluka esifutshane.

I-Ferromagnetic resonance over-voltage inokutshisa ngokulula i-voltage transformer kwaye ibangele umonakalo kwisibambi, esinokubangela ukuba isibambisi siqhume. Ezi ziphumo ziya kusongela ngokunzulu ukugqunywa kwesixhobo sombane wegridi kwaye zibeke emngciphekweni ukusebenza ngokukhuselekileyo kwegridi yamandla.

Ukuze kuncitshiswe i-capacitive current kumhlaba xa kukho i-single-phase-grounding fault, kuyimfuneko ukufaka i-arc yokunciphisa i-coil kunye nezinye izixhobo zembuyekezo kwindawo engathathi hlangothi ye-transformer. Ngoko ke, kuyimfuneko ukuseka ngesandla indawo engathathi hlangothi ukwenzela ukuba i-coil yokunciphisa i-arc inokudibaniswa kwindawo engathathi hlangothi ukunciphisa i-grounding short-circuit breaking current kunye nokuphucula ukuthembeka kwenkqubo yokunikezelwa kwamandla.

■ Ukusetyenziswa kwangoku ekhaya nakwamanye amazwe

I-grounding transformer e-China idla ngokuthatha i-Z-type wiring (okanye i-zigzag wiring). Ukuze ulondoloze utyalo-mali kunye nendawo yokubeka i-substation, i-winding yesithathu idla ngokudityaniswa kwi-transformer yomhlaba ukuze ithathe indawo ye-transformer esetyenziselwa ukubonelela umbane wezixhobo ezisetyenziswa kwi-substation. Ngokomgangatho wesizwe we-Reactor, indlela yokumisa ye-grounding transformer inokohlulwa ibe yisiseko esithe ngqo; Isekelwe kwi-reactor, ukuxhathisa kunye ne-arc yoxinzelelo lwekhoyili. Ukumisa ngokuthe ngqo akuzange kusetyenziswe e-China, kodwa amanye amasebe ophando lwamandla ombane aqalise ukuxoxa ngalo mba. I-grounding transformer kumazwe angaphandle ngokuqhelekileyo ithatha okanye i-Z-type uxhumano, esetyenziselwa i-10kV inkqubo engabonakaliyo kwaye yenza ukhuseleko olusisiseko lwenethiwekhi yokusabalalisa. Xa inkqubo inesiphoso somhlaba, i-grounding transformer ibonisa ukuxhatshazwa okuphezulu kulandelelwano oluhle kunye nokulandelelana okungalunganga kwangoku kunye nokuchasana okuphantsi kwe-zero ngokulandelelana kwangoku, okwenza ukukhuselwa komhlaba kusebenze ngokuthembekileyo.

■ Isiguquli sokumisa inqanaba lesithathu

Isiguquli sokumisa inqanaba lesithathu Olu hlobo lwesiguquli lusebenzisa udidi lwe-Z (okanye i-zigzag wiring). Umahluko ukusuka abaguquli eziqhelekileyo kukuba ikhoyili isigaba ngasinye yahlulwe ngamaqela amabini kunye nenxeba kwi pole magnetic kwesi sigaba umva. Inzuzo yolu qhagamshelo kukuba ulandelelwano lwemagnethi olulandelelanayo lunokuhamba ecaleni kwepali kazibuthe, ngelixa ulandelelwano lwemagnethi olulandelelanayo lweziguquli eziqhelekileyo luhamba ecaleni kwesekethe yokuvuza kwemagnethi. Ke ngoko, i-zero i-impedance yolandelelwano lwe-Z-type grounding transformers incinci kakhulu (malunga ne-10 Ω), ngelixa i-transformer eqhelekileyo inkulu kakhulu. Ngokwemigaqo, umthamo we-transformer eqhelekileyo kunye ne-arc yokunciphisa i-coil ayiyi kudlula i-20% yomthamo we-transformer. I-Z-type transformer inokuxhotyiswa ngekhoyili yokucinezela i-arc enomthamo we-90% ~ 100%. Ukongeza kwi-arc yokunciphisa i-coil, i-grounding transformer inokuxhotyiswa nomthwalo wesibini, onokuthatha indawo ye-transformer yesitishi, ngaloo ndlela igcina iindleko zotyalo-mali.

■ Isiguquli sokumisa inqanaba elinye

Isigaba esinye sokumisa isiguquli sokumisa isigaba esinye sisetyenziswa ikakhulu kwijenereyitha enenqaku elingathathi hlangothi kunye nekhabhinethi engathathi hlangothi yokumelana nekhabhinethi yeSatons yokuguqula ixabiso kunye nomthamo wekhabhinethi yokumelana.

■ Iimpawu zokusebenza

(1) I-impedance ye-zero ephantsi yolandelelwano ukuqinisekisa ukukhutshwa kwe-zero ngokulandelelana kwangoku;

(2) I-impedance ephezulu yokunciphisa ukunciphisa akukho mthwalo wangoku;

(3) Ilahleko ephantsi engenamthwalo ukugcina ukusetyenziswa kwamandla okusebenza kwansuku zonke.

■ Imo yocingo

Uqhagamshelwano lweYNyn

I-transformer enale ndlela yokudibanisa ngokubanzi ithatha inqanaba lesithathu kwikholamu yentsimbi engundoqo, kwaye indawo engathathi hlangothi kwicala le-voltage ephezulu inokudityaniswa kunye ne-arc yokucinezela ikhoyili ukuqonda isiseko. Nangona kunjalo, xa inqanaba elinye elisekelwe ku-zero ulandelelwano lwangoku liqukuqela kwicala le-voltage ephezulu, amandla emagnethi olandelelwano oluyiqanda alukwazi ukulungelelaniswa nokubakho kwemagnethi yesibini, kwaye ulandelelwano lwemagnethi olulandelelanayo lweziro kwicala elinye alunakwenza iluphu ngaphakathi. Ikholamu ezintathu zentsimbi engundoqo, ukuze inani elikhulu le-zero yolandelelwano lwemagnethi likwazi ukudlula kuphela kwi-clamp, i-oyile kunye ne-oyile yetanki yomzimba ukwenza i-loop evaliweyo, ngaloo ndlela ibangela ilahleko eyongezelelweyo kwitanki yeoli kunye ne-clamp, ekhokelela ekufudumeni kwendawo; Ukusetyenziswa komthamo wesiguquli kulinganiselwe. Imigaqo yokusebenza efanelekileyo yecandelo lamandla laseTshayina lenze la malungiselelo alandelayo kwimeko yokusebenza yenqaku elingathathi hlangothi loqhagamshelo lwekhoyili yocinezelo ye-YNyn yoqhagamshelo lwesiguquli:

(1) Umthamo wekhoyili yokucinezela i-arc awuyi kudlula i-20% yomthamo olinganisiweyo we-transformer;

(2) Ukuhla kwamandla ombane olandelelwano lwe-zero okuveliswa ngu-zero wolandelelwano lwangoku ohamba kwikhoyili yokucinezela i-arc kwi-transformer akuyi kudlula i-10% yombane wesigaba esilinganisiweyo;

Imowudi yokudibanisa ye-YNd yokudibanisa i-transformer kunye ne-arc yokunciphisa i-coil XL ibonakala ngokuba uxhulumaniso lwe-triangular kwicala lesibini lunokubonelela ngendlela evaliweyo ye-zero yokulandelelana kwangoku, ngoko ukulandelelana kwe-zero kuncinci. Ukongeza, okoko ulandelelwano lweziro olunokubakho lwemagnethi eprayimari kunye neyesibini kwikholamu engundoqo nganye ilungelelene, ukuvuza kwemagnethi okulandelelana kwezero nako kuncinci. Nangona kunjalo, xa uxhulumaniso lwe-YN lungaphandle, ukulandelelana kwe-zero ilahleko eyongezelelweyo ebangelwa kwi-tank yeoli kunye nezinye izinto azikwazi ukuphetshwa ngokupheleleyo. Xa idityaniswe nekhoyili yocinezelo ye-arc, ukusetyenziswa komthamo wayo kusaza kuthintelwa. Uphando lovavanyo lwangaphandle lubonisa ukuba imowudi yokusebenza evumelekileyo ye-YNd eqhagamshelwe i-grounding transformer yile:

(1) Xa umthwalo ogcweleyo wesibini uqhelekileyo, umthamo wekhoyili yokucinezela i-arc edityaniswe kwicala le-YN awuyi kudlula i-50% yomthamo olinganisiweyo we-transformer;

(2) Xa umthwalo yesibini kuphela 50% umthamo isiguquli ngamaxesha aqhelekileyo, arc ukucinezelwa coil umthamo ingalingana nomthamo ezilinganisiweyo we transformer.

Nangona icala lesibini lolu xhulumaniso linokubonelela ngamandla kwimithwalo yengingqi okanye i-substation ngokwayo, isicelo salo siya kunqunyulwa kakhulu ngenxa yokuba uxhulumaniso lwe-triangular lunzima ukubonelela amandla kumandla ombane kunye nabasebenzisi bokukhanyisa ngexesha elifanayo.

YN, uqhagamshelo oluvulekileyo lwe-d ludityaniswe ne-arc-suppression coil XL, efana ne-YNd uxhumano. Imowudi yoqhagamshelo ye-d evulekileyo inokudityaniswa kunye ne-resistor okanye i-reactor kwicala likanxantathu ovulekileyo ukulungisa i-zero-sequence reactance ye-transformer, kunye nokudibanisa kwe-resistor nako kunokucinezela i-resonance ye-ferromagnetic yenethiwekhi. Ukuba i-column ye-five-five-column yentsimbi iyamkelwa, ixabiso le-impedance yolandelelwano lwe-zero linganyuswa kakhulu, kwaye kunokwenzeka ukuba ushiye i-coil yokunciphisa i-arc, kodwa isakhiwo sinzima kwaye iindleko zonyuswa. Ukongeza, ukusetyenziswa okwesibini koqhagamshelo unxantathu ovulekileyo akakwazi ukuhlangabezana neemfuno zonikezelo lwamandla kwimithwalo yengingqi kunye namandla okuzisebenzisa, ngoko le ndlela ayisetyenziswanga ngokubanzi.

I-ZN, i-yn yokudibanisa i-transformer idibaniswe ne-arc yokucinezela i-coil XL, eyindlela yokudibanisa eqhelekileyo ye-grounding transformer. Ngenxa yokuba ulandelelwano lwemagnethi olunokubakho kwisiqingatha somoya ongasentla nasezantsi kwikholamu enye yentsimbi yendlela yoqhagamshelo lwezigzag ilingana nobukhulu obufanayo kunye necala elichaseneyo, elichaseneyo, ulandelelwano lokuvuza lokuvuza luyancipha ukuya kwixabiso elincinci kakhulu. , ukwenzela ukuba ixabiso layo lokuphendula ngokulandelelana kwe-zero lincinci kakhulu, kwaye umthamo walo unokulingana nomthamo wekhoyili yokucinezela i-arc edibeneyo.

I-transformer yomhlaba esetyenziswa ngokubanzi ekhaya nakwamanye amazwe idityaniswe ikakhulu ngale ndlela. Ukusukela ukuba indlela ye-yn ye-junction yamkelwe kwicala le-voltage ephantsi, inokubonelela ngamandla asekhaya okanye amandla okuzisebenzisela esisikhululo ngexesha elinye. Umthamo wecala lamandla ombane ophantsi udla ngokuba mncinci kunecala lombane ophezulu. Kwiimeko ezininzi, umthamo wecala lombane ophantsi ungaphakathi koluhlu lwe-80-200kVA.

Nangona umthamo olinganisiweyo wecala eliphezulu le-voltage linokulingana nomthamo we-coil yokucinezela i-arc edityanisiweyo, uxhulumaniso olumise okwe-Z luya kuba namaxesha angama-1.15 ngaphezu koqhagamshelwano olufana no-Y, ngoko ke amandla okwenene e-transformer yomhlaba kufuneka ibe ngamaxesha angama-1.15 omthamo wekhoyili yokucinezelwa kwe-arc.

■ Umgaqo wokusebenza

Umzobo womgaqo wokusebenza we-grounding transformer kwimeko yesiphambeko sesigaba esisodwa kwinkqubo iboniswa yi-wiring ye-ZNyn eqhelekileyo. Xa i-transformer yokumisa idlula kubungakanani obuthile be-zero yolandelelwano lwangoku ngexesha lokusebenza, yangoku equkuqelayo phakathi kwamajiko-jiko amabini akwinqanaba elinye kwikholamu enye yentsimbi ikwicala elichaseneyo kwaye ubungakanani bulingana, ukuze amandla ombane aveliswa ngumbane. Ulandelelwano lwangoku lwe-zero luchasana nje ne-offset, ukuze i-impedance yolandelelwano lwe-zero nayo incinci kakhulu.

Xa i-transformer yomhlaba ingaphumeleli, indawo engathathi hlangothi inokuhamba ngembuyekezo yangoku. Ngenxa ye-impedance encinci ye-zero-sequence, xa i-zero-sequence yangoku idlula, ukuhla kwe-voltage ye-impedance eyenziweyo kufuneka kube kuncinci kangangoko ukuqinisekisa ukhuseleko lwenkqubo. Ngenxa yokuba i-grounding transformer ineempawu ze-impedance ephantsi yolandelelwano lwe-zero, xa impazamo yenqanaba elilodwa lesiseko lenzeka kwisigaba C, inqanaba le-C lomhlaba langoku I liqukuqela kwindawo engathathi hlangothi emhlabeni, kwaye yahlulwe yaba ngamacandelo amathathu alinganayo ukugeleza kuwo. isiguquli-siseko. Ekubeni imisinga yezigaba ezithathu ezigeleza kwi-transformer yomhlaba zilingana, ukufuduka kwendawo engathathi hlangothi ye-N kuhlala kungatshintshi, kwaye i-voltage yesigaba sesithathu ihlala i-symmetrical.

Nangona kunjalo, kwinkqubo yokuvelisa, ukujika kunye nemilinganiselo yejometri ye-windings ephezulu kunye nesezantsi ye-high-voltage windings ayikwazi ukulingana ngokupheleleyo, nto leyo eyenza ukuba kungenzeki ukuba amandla omagnetic aveliswa ngu-zero ngokulandelelana kwangoku ukuba aguqulwe ngokuthe ngqo ngokuchasene. isalathiso, kwaye isavelisa i-impedans ethile yolandelelwano lwe-zero, ngesiqhelo malunga ne-6-10 Ω. Xa kuthelekiswa ne-zero i-impedance yokulandelelana kwenkwenkwezi edibeneyo ye-transformer ye-600 Ω, izibonelelo zayo ziyabonakala. Ukongeza, i-zigzag grounding transformer nayo inokwenza ukuba akukho mthwalo wangoku kunye nokulahlekelwa ngumthwalo omncinci kangangoko kunokwenzeka. Xa kuthelekiswa nesiguquli sokudityaniswa kweenkwenkwezi, isigaba ngasinye sentsimbi yodibaniso lwezigzag siqulunqwa ngamajiko-jiko eentsika ezimbini zentsimbi. Ngokomzobo wevektha, xa uthelekisa ne-transformer yoqhagamshelo lwenkwenkwezi eqhelekileyo, kufuneka ihlatywe amaxesha ayi-1.16 ngaphezulu xa umbane ufana. Iamplitude ye-zero i-impedance yolandelelwano kunye nolandelelwano oluqinisekileyo lokuthintela uthungelwano losasazo lwasezidolophini kunye nenqanaba elinye lokumisa phantsi kwemowudi yokumelana nenqaku elingathathi hlangothi yokwahluka kakhulu. Xa imisinga yolandelelwano lwezigaba ezithathu ezilungileyo nezingalunganga zihamba, amandla ombane kwikholamu yentsimbi engundoqo nganye yesiguquli esisezantsi sisimbuku se-phasors yesakhono somagnetic samanqanaba amabini ahlukeneyo kwikholamu engundoqo yentsimbi. Amandla kazibuthe kwiintsika ezintathu ezingundoqo zentsimbi liqela lemiyinge yezigaba ezintathu zokulingana kunye nokwahlukana kwesigaba se-120 °. Ukuqukuqela kozibuthe okwenziwayo kunokwenza iluphu kwiintsika ezintathu ezingundoqo zentsimbi. Ukuxhathisa kwamagnetic kwisekethe yamagnetic kuncinci, i-magnetic flux inkulu, kwaye amandla anyanzeliswayo makhulu, abonisa ulandelelwano olukhulu oluhle kunye ne-impedance yokulandelelana okungalunganga; Ngoko ke, i-transformer yomhlaba ineempawu ze-impedance enkulu kunye ne-negative yolandelelwano kunye ne-impedance encinci yokulandelelana kwe-zero.

■ Imilinganiselo yobugcisa engundoqo

Ukuze kuhlangatyezwane neemfuno zembuyekezo ye-arc yokucinezelwa kwe-coil kuthungelwano lokusasazwa, kunye nokuhlangabezana neemfuno zamandla e-substation kunye nomthwalo wokukhanyisa, i-Z-uhlobo lokudibanisa i-transformer ikhethiwe, kwaye iiparameters eziphambili ze-grounding transformer kufuneka zibekwe ngokufanelekileyo.

(1) Umthamo wecala eliphambili le-coil yokucinezela i-arc. Ngokwenkcazo yomthamo wekhoyili ekhoyo yokucinezela i-arc, kuyacetyiswa ukuba usete umthamo we-transformer yomhlaba njenge-1.05-1.15 amaxesha omthamo we-arc yokunciphisa i-coil. Umzekelo, umthamo we-grounding transformer exhotyiswe nge-coil enye ye-200kVA arc yokucinezela yi-215kVA.

(2) Iyonke yangoku equkuqelayo kwindawo engathathi hlangothi kwi-transformer kwimeko yesiphoso senqanaba elinye lembuyekezo yenqaku elingathathi hlangothi:

Apho:

U-U ngumbane womgca wenethiwekhi yokusabalalisa (V); I-Zx kukuthintelwa kwekhoyili yocinezelo ye-arc (Ω);

I-Zd yi-primary zero i-impedance yolandelelwano lwe-grounding transformer (Ω/isigaba);

I-Zs yinkqubo yothintelo (Ω);

Ubude bexesha lembuyekezo yenqaku elingathathi hlangothi liya kufana nelo le-coil yokunciphisa i-arc, eya kuba yi-2 iiyure njengoko kuchaziwe.

(3) I-Zero i-impedance yolandelelwano I-Zero i-impedance yolandelelwano yiparameter ebalulekileyo ye-grounding transformer, enempembelelo ebalulekileyo ekukhuselweni kwe-relay ukunciphisa inqanaba elinye lokumisa i-short-circuit current kunye nokucinezela ukugqithisa. Kwi-zigzag (uhlobo lwe-Z) kunye neenkwenkwezi / i-delta evulekileyo edibeneyo i-grounding transformers ngaphandle kweekhoyili zesibini, kukho i-impedance enye kuphela, oko kukuthi i-impedance ye-zero sequence, ukwenzela ukuba isebe lokuvelisa likwazi ukuhlangabezana neemfuno zesebe lamandla.

(4) Ilahleko yiparameter yokusebenza ebalulekileyo ye-grounding transformer. Kwi-transformer yomhlaba kunye nekhoyili yesibini, ilahleko yayo yokungabikho komthwalo inokufana neyokuguquguquka okuphindwe kabini kunye nomthamo ofanayo. Ukulahlekelwa ngumthwalo, xa icala lesibini lisebenza ngokupheleleyo, ukulahlekelwa ngumthwalo wecala eliphambili lingaphantsi kwe-transformer ejikeleza kabini enomthamo ofanayo kunye necala lesibini ngenxa yomthwalo wokukhanya wecala eliphambili.

(5) Ngokomgangatho wesizwe, ukunyuka kwamaqondo obushushu kwi-grounding transformer kukulandelayo:

1) Ukunyuka kwamaqondo obushushu phantsi komlinganiselo oqhubekayo wangoku kuya kuhambelana nemimiselo yomgangatho wesizwe kwiinguqu zodidi ezomileyo zoguqulo lwamandla ngokubanzi, kodwa zisebenza ngokukodwa kwiinguqu ezisezantsi ezinomthwalo rhoqo kwicala lesibini;

2) Xa ixesha lomthwalo wexesha elifutshane langoku lingaphantsi kwe-10s (ingakumbi xa indawo engathathi hlangothi idityaniswe nokumelana), ukunyuka kwamaqondo obushushu kuya kuhambelana nemimiselo yomgangatho wesizwe soguqulo lwamandla kumda wokunyuka kobushushu phantsi kwesekethe emfutshane. iimeko;

I-3) Ukunyuka kweqondo lokushisa kwe-coil ye-grounding transformer kunye ne-arc yokunciphisa i-coil xa isebenza kunye iya kuhambelana nemimiselo yokunyuka kweqondo lokushisa kwe-coil yokunciphisa i-arc: iqondo lokushisa elijikelezayo eliqhubeka lihamba ngokuphindaphindiweyo kwi-80K, eyona nto isebenzayo inkwenkwezi/i-delta evulekileyo yokudibanisa isiguquli sokumisa; Ukuvala ubuninzi bexesha lokuhamba kwexesha elilinganisiweyo langoku elichazwe njenge-2h, ubushushu obuchaziweyo yi-100K.

• Unyakakelwe
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• Uhlobo lweshishini
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• Ilizwe / Ingingqi
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• Ishishini eliphambili
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• Iimveliso eziphambili
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• Ishishini lomntu osemthethweni
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• Abasebenzi bazonke
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• Ixabiso lokuphuma lonyaka
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• Ukuthengisa ngaphandle
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• Abathengi abasebenzayo
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