Uhlalutyo loKhuseleko lweTransformer kwiRelay Protection

1. Iimpazamo eziqhelekileyo kunye nokungahambi kakuhle kwee-transformers

Iziphene zetransformer zinokwahlulwa zibe ziziphene zangaphakathi neziphene zangaphandle.

Iziphene zangaphakathi zibhekisa kwiziphene ezenzeka ngaphakathi kwetyala, kuquka iimpazamo ze-phase-to-phase of windings, iimpazamo ze-inter-turn short-circuit ze-one-phase windings, iimpazamo ze-short-circuit phakathi kwe-windings kunye ne-iron cores, kunye neziphene zokuqhawula ii-windings.

Iziphene zangaphandle zibhekisa kwiiphene ezahlukeneyo ze-phase-to-phase short-circuit phakathi kwee-lead wire zangaphandle ze-transformer, kunye neziphene zomhlaba ze-single-phase ezenzeka xa i-insulating bushing yee-lead wires ikhanya kwi-shell yebhokisi.

Ukusilela kwetransformer kuyingozi kakhulu. Ingakumbi xa kukho impazamo yangaphakathi, i-arc yobushushu obuphezulu eveliswa ngumsinga we-short-circuit ayizukutshisa kuphela i-insulation kunye ne-iron core ye-transformer winding, kodwa ikwabangela ukuba ioyile yetransformer ibole kwaye ivelise inani elikhulu legesi, nto leyo ebangela ukuguquka okanye ukuqhuma kwegobolondo letransformer. Ke ngoko, kufuneka inqunyulwe xa itransformer ingaphumeleli.

Iimeko ezingaqhelekanga zetransformer ziquka ukugqithiswa kakhulu, inqanaba eliphantsi leoyile, ukugqithisa okubangelwa yi-external short circuit, ubushushu obuphezulu beoyile yetransformer esebenza, ubushushu obuphezulu bokujika, uxinzelelo oluphezulu lwetransformer, kunye nokusilela kwenkqubo yokupholisa. Xa itransformer ikwimeko yokusebenza engaqhelekanga, kufuneka kunikwe isignali yesilumkiso.

2. Uqwalaselo lokhuseleko lwe-transformer

Ukhuseleko oluphambili kwiimpazamo ze-short-circuit: ikakhulu ukhuseleko lokwahluka olude, ukhuseleko lwegesi enzima, njl.

Ukhuseleko olugciniweyo kwiimpazamo ze-short-circuit: ikakhulu ukhuseleko oluhlanganisiweyo lokuvimba i-over-current, ukhuseleko oluphezulu lwe-zero-sequence (ulwalathiso), ukhuseleko oluphantsi lwe-impedance, njl.

Ukhuseleko olungaqhelekanga lokusebenza: ikakhulu lubandakanya ukhuseleko lokugqithisela, ukhuseleko lokuvuthela kakhulu, ukhuseleko lwegesi ekhanyayo, ukhuseleko lwesithuba esingathathi cala, ukhuseleko lokusilela kweoyile yobushushu kunye nokhuseleko lokungaphumeleli kwenkqubo yokupholisa, njl.

3. Ukhuseleko olungelulo umbane

Ukhuseleko lwe-transformer olusebenzisa ubungakanani obungengobombane njengeoyile, igesi, kunye nobushushu be-transformer lubizwa ngokuba lukhuseleko olungengobombane. Ngokuyintloko lubandakanya ukhuseleko lwegesi, ukhuseleko loxinzelelo, ukhuseleko lobushushu, ukhuseleko lwenqanaba leoyile kunye nokhuseleko olupholileyo olupheleleyo. Ukhuseleko olungengobombane lusebenza ekukhubekeni okanye ekuthumeleni ileta ngokweemfuno zesiza.

(1) Ukukhuselwa kwegesi

Xa kuvela impazamo ngaphakathi kwe-transformer, ngenxa yesenzo se-current-circuit current kunye ne-arc kwindawo ye-short-circuit, inani elikhulu legesi liya kuveliswa ngaphakathi kwe-transformer, kwaye isantya sokuhamba kweoyile ye-transformer siya kukhawuleziswa. Ukhuseleko olufumaneka ngokusebenzisa ukuhamba kwegesi kunye neoyile lubizwa ngokuba lukhuselo lwegesi.

Ukhuseleko lwegesi ekhaphukhaphu: Xa kukho impazamo encinci okanye ukungaqheleki ngaphakathi kwi-transformer, indawo yempazamo ishushu kakhulu, nto leyo ebangela ukuba inxalenye yeoyile yande, igesi ekwioyile yenza amaqamza ize ingene kwi-gas relay, kwaye ukhuseleko lwegesi ekhaphukhaphu lusebenza ukuthumela isignali yegesi ekhaphukhaphu.

Ukhuseleko olunzima lwegesi: Xa kuvela impazamo enkulu kwitanki yeoyile yetransformer, umsinga wempazamo mkhulu, kwaye i-arc ibangela ukuba i-oyile yetransformer eninzi ibole, ivelise igesi eninzi kunye nokuhamba kweoyile. Ingxaki yokungqubana kwempembelelo yenza ukuba i-gas relay ibe nkulu isebenze, ithumele isignali yegesi enzima kwaye iphazamise i-outlet. Susa i-transformer.

Ukhuseleko olunzima lwegesi lolona khuselo luphambili kwiimpazamo zangaphakathi zetanki yeoyile, kwaye lunokubonakalisa iimpazamo ezahlukeneyo ngaphakathi kwetransformer. Xa inani elincinci leesekethe ezimfutshane eziphakathi kwe-inter-turn livela kwitransformer, nangona umbane wephutha mkhulu, umbane we-differential owenziwe kukhuseleko lomahluko usenokuba mkhulu, kwaye ukhuseleko lomahluko lunokwala ukusebenza. Ke ngoko, kwimpazamo yangaphakathi yetransformer, kuyimfuneko ukuthembela kukhuseleko olunzima lwegesi ukususa impazamo.

(2) Ukhuseleko loxinzelelo

Ukhuseleko loxinzelelo lukwalukhuseleko oluphambili kwiimpazamo zangaphakathi kwitanki yetransformer. Iqulethe ukukhululeka koxinzelelo kunye nokhuseleko lotshintsho olukhawulezileyo loxinzelelo, olusetyenziselwa ukuphendula kuxinzelelo lweoyile yetransformer.

(3) Ukhuseleko lobushushu kunye nenqanaba leoyile

Xa ubushushu betransformer bunyuka bufikelela kwixabiso lesilumkiso, ukhuseleko lobushushu luya kuthumela isignali yesilumkiso, kwaye luqalise i-standby cooler.

Xa ioyile yetransformer ivuza okanye inqanaba leoyile lihla ngenxa yezinye izizathu, ukhuseleko lwenqanaba leoyile luya kusebenza kwaye luthumele isignali yesilumkiso.

(4) Ukhuseleko olupholileyo oluhlala ixesha elide

Xa i-transformer cooler isebenza ngokupheleleyo, ubushushu be-transformer buya kunyuka. Ukuba ayiphathwanga ngexesha, inokubangela umonakalo kwi-insulation ye-transformer winding. Ke ngoko, xa i-cooler imisiwe ngokupheleleyo ngexesha lokusebenza kwe-transformer, ukhuseleko luya kuthumela isignali ye-alamu kwaye luyinqumle i-transformer emva kokulibaziseka ixesha elide.

4. Ukhuseleko olwahlukileyo

Ukhuseleko lomahluko wetransformer lolona khuselo luphambili lobungakanani bombane betransformer, kwaye uluhlu lwayo lokhuseleko yinxalenye ejikelezwe ziitransformer zangoku kumacala omabini. Xa iimpazamo ezifana ne-phase-to-phase short-circuit kunye ne-inter-turn short-circuit ye-winding zenzeka ngaphakathi kolu luhlu, ukhuseleko lomahluko kufuneka lusebenze.

Ngokuphathelele umgaqo wokhuseleko lomahluko we-transformer, sele sixoxe ngokweenkcukacha ngaphambili, abahlobo abayidingayo banokuphonononga umxholo ofanelekileyo kwiirekhodi zembali 6, 7, kunye no-8. Andiyi kungena kwiinkcukacha malunga noku, kwaye apha ndiza kongeza nje ezinye iingcamango malunga nomsinga we-excitation inrush.

(1) Umsinga wokungenisa umoya wetransformer

Umsinga wokukhupha umoya oveliswayo xa i-transformer ikhutshwa ngomoya ubizwa ngokuba yi-excitation inrush current. Ubukhulu bomsinga wokukhupha umoya bunxulumene nolwakhiwo lwe-transformer, i-engile yokuvala, umthamo, i-residual magnetism ngaphambi kokuvala kunye nezinye izinto. Umlinganiselo ubonisa ukuba xa i-transformer ikhutshwa ngomoya, umsinga wokukhupha umoya oveliswayo ngenxa yokugcwala kwe-iron core mkhulu kakhulu, ngesiqhelo uphindwe kabini ukuya kwi-6 yomsinga olinganisiweyo, kwaye ubuninzi bunokuba ngaphezu kwezihlandlo ezisi-8. Ekubeni umsinga wokukhupha umoya oveliswayo ungena kwi-transformer kuphela kwicala lokutshaja, umsinga omkhulu wokukhupha umoya uya kuveliswa kwisekethe yokwahluka, nto leyo ebangela ukungasebenzi kakuhle kokhuseleko lokwahluka.

Umsinga womoya ovuselelayo uneempawu ezilandelayo: a. Ixabiso lomsinga womoya ovuselelayo likhulu kakhulu kwaye liqulathe izinto ezicacileyo ezingezizo ezexesha elithile; b. Imo ye-wave icacile kwaye ingenaxesha; c. Iqulathe izinto ezicacileyo ze-harmonic eziphezulu, ingakumbi i-harmonic component yesibini. Ngokucacileyo; d, umsinga womoya ovuselelayo uyancipha.

Ngokweempawu ezingentla zomsinga wokungena, ukuze kuthintelwe ukungasebenzi kakuhle kokhuseleko lokwahluka kwetransformer olubangelwa ngumsinga wokungena, kusetyenziswa imigaqo emithathu kule projekthi: umxholo wesibini ophezulu we-harmonic, i-waveform engalinganiyo, kunye ne-angle enkulu ye-waveform discontinuity ukuze kufezekiswe ukuvinjwa kokhuseleko lokwahluka.

(2) Umgaqo wesibini wokuqhoboshela i-harmonic

Eyona nto iphambili kwi-harmonic braking yesibini kukusebenzisa i-harmonic component yesibini kwi-differential current ukugweba ukuba i-differential current yi-fault current okanye i-inrush current evuyisayo. Xa ipesenti ye-harmonic component yesibini kunye ne-fundamental wave component ingaphezulu kwexabiso elithile (ngesiqhelo yi-20%), kugwetywa ukuba i-differential current ibangelwa yi-excitation inrush current, kwaye ukhuseleko lwe-differential luyavalwa.

Ke ngoko, okukhona umlinganiselo wesibini wokuqhobosheka kwe-harmonic umkhulu, kokukhona umlinganiselo wesibini wokuqhobosheka kwe-harmonic oqulethwe kwi-fundamental wave uvumelekile, kwaye isiphumo sokuqhobosheka siya kuba sibi.

(3) Ukhuseleko olukhawulezayo lokwaphuka oluhlukeneyo

Xa kuvela isiphene esinzulu ngaphakathi kwi-transformer kwaye i-CT igcwele ngenxa yomsinga omkhulu wesiphane, umsinga wesibini we-CT ukwanazo nenani elikhulu lezinto ezihambelanayo. Ngokwenkcazo engentla, oku kunokubangela ukhuseleko lokwahluka ngenxa yokuqhawuka kwesibini kwe-harmonic. Vimba okanye ulibazise isenzo. Oku kuya konakalisa kakhulu i-transformer. Ukuze kusonjululwe le ngxaki, ukhuseleko lokwahluka ngokukhawuleza ludla ngokubekwa.

Into ekhawulezayo yokwahlukana ngokwenene yinto exabisekileyo yokwahlukana yokukhusela umahluko wexesha elide. Ngokungafaniyo nezinto eziqhelekileyo zokwahlukana, ibonisa ixabiso elisebenzayo lomsinga wokwahlukana. Nokuba injani na i-waveform yomsinga wokwahlukana kunye nobukhulu be-harmonic component, ukuba ixabiso elisebenzayo lomsinga wokwahlukana lidlula ixabiso lokuseta lomsinga wokwahlukana (ngesiqhelo liphezulu kunexabiso lokuseta lomsinga wokwahlukana), iya kusebenza ngoko nangoko ukusika i-transformer ngaphandle kokuvuselela. Ukuthintela iikhrayitheriya ezifana nomsinga wokungena.

Oku kulandelayo kwazisa ukhuseleko olugciniweyo lwe-transformer

Kukho iintlobo ezininzi zolungiselelo lokhuseleko oluxhasayo lweetransformer. Le ngxaki ibandakanya iintlobo ezimbini zokhuseleko oluxhasayo: ukhuselo olunzima lokuvimba umbane ogqithisileyo kunye nokhuseleko lokumisa umhlaba kwiitransformer.

1. Ukhuseleko olugqithisileyo loxinzelelo olunzima

Ukhuseleko oluntsonkothileyo lokuvimba umbane ogqithisileyo lukhuselo oluxhasayo kwiimpazamo zesekethe ezimfutshane ze-transformer ezinkulu neziphakathi. Lufanelekile kwiitransformer ezinyukayo, iitransformer zoqhagamshelwano lwenkqubo kunye neetransformer ezinyukayo ezikhuselekileyo umbane ogqithisileyo ezingenako ukuhlangabezana neemfuno zobuntununtunu. Umbane odibeneyo owenziwe yi-voltage elandelelanayo engalunganga kunye ne-voltage ephantsi unokubonakalisa iimpazamo ezahlukeneyo ngaphakathi koluhlu lokhuseleko, nto leyo enciphisa ixabiso lokuseta lokhuseleko olugqithisileyo kwaye iphucule ubuntununtunu.

Ukhuseleko lwe-overcurrent ye-voltage edityanisiweyo lwenziwe yi-composite voltage element, i-overcurrent element kunye ne-time element. I-input current yokhuseleko yi-secondary-phase three-phase current ye-CT kwicala le-transformer, kwaye i-input voltage yi-secondary-phase three-phase voltage ye-PT kwicala le-transformer okanye kwamanye amacala. Ukukhusela i-microcomputer, i-voltage yale cala inokubonelelwa kwamanye amacala ngesoftware, ukuqinisekisa ukuba ukhuseleko lwe-overcurrent yalo naliphi na icala lungasetyenziswa xa i-PT yalo naliphi na icala ihlaziywa. I-action logic iboniswe kumfanekiso ongezantsi.

2. Ukukhuselwa komhlaba kwetransformer

Ukhuseleko olungasemva lweziphene ze-grounding short-circuit ze-transformers ezinkulu neziphakathi ludla ngokuquka: ukhuseleko lwe-zero-sequence overcurrent, ukhuseleko lwe-zero-sequence overvoltage, ukhuseleko lwe-gap, njl. Oku kulandelayo yintshayelelo emfutshane esekelwe kwiindlela ezintathu ezahlukeneyo ze-grounding ze-neutral point.

(1) Ingongoma engathathi cala isekelwe ngqo

Kwiitransformer ezine-voltage ye-110kV nangaphezulu apho inqaku lazo elingathathi cala lisekelwe ngqo, kufuneka kufakwe ukhuseleko lwangoku oluyi-zero-sequence oluphendula kwiimpazamo zomhlaba ecaleni kwenkqubo yokumisa umhlaba enkulu. Kwiitransformer ezisekelwe ngqo kumacala aphezulu naphakathi, ukhuseleko lwangoku oluyi-zero-sequence kufuneka lube necala, kwaye icala kufuneka likhombe kwiibha zebhasi kwicala ngalinye.

Umgaqo wokhuseleko lwangoku olulandelanayo nolufana nolo lokhuseleko lwangoku olulandelanayo nolulandelanayo, nceda ujonge kwiSihloko sama-30. Umsinga olandelanayo nolulandelanayo unokuthathwa kumsinga wesibini we-CT engathathi cala, okanye unokuzivelela ngokwawo ngumsinga wesibini olandelanayo nolu ...

Kwiitransformer ezinkulu ezinee-twing ezintathu, ukhuseleko lwangoku lwe-zero-sequence olunezigaba ezintathu lungasetyenziswa. Phakathi kwazo, iCandelo I kunye neCandelo II zinezikhokelo, kwaye iCandelo III alinazo izikhokelo. Ngokuqhelekileyo kukho amanqanaba amabini okulibaziseka kwicandelo ngalinye, kwaye uluhlu lwempazamo luncitshiswa ngokulibaziseka okufutshane (ukutsiba i-bus coupler okanye iswitshi kwicala eliphambili lebha), kwaye i-transformer iyanqunyulwa ngokulibaziseka okude (ukutsiba iswitshi enamacala amathathu). Uqwalaselo oluthile lokhuseleko lumiselwa ngokwemeko yokwenyani.

Njengoko kubonisiwe kumfanekiso, emva kokuba icandelo le-I okanye le-II lokhuseleko lwangoku oluhamba ngolandelelwano lwe-zero-sequence lisebenza, qala ngokutsiba i-bus coupler okanye iswitshi kweli cala emva kokulibaziseka okufutshane i-t1 okanye i-t3 ukuze unciphise ububanzi bempazamo. Ukuba impazamo isekhona, emva kwexesha elide i-Delay t2 okanye i-t4 tsiba iswitshi enamacala amathathu ukuze unqumle i-transformer. Icandelo lesi-III alinacala, kwaye i-transformer iyanqunyulwa ngqo emva kokulibaziseka.

(2) Ingongoma engathathi cala ayisekelwanga

Umsinga we-zero-sequence udlula kwindawo engathathi hlangothi ye-transformer ukuze wenze isekethe ye-zero-sequence. Nangona kunjalo, ukuba iindawo ezingathathi hlangothi zazo zonke ii-transformer zisekelwe, umsinga we-short-circuit kwindawo yokumisa umhlaba uya kuthuthwa kwi-transformer nganye, nto leyo eya kunciphisa uvakalelo lokhuseleko lwe-zero-sequence overcurrent. Ke ngoko, ukuze kuncitshiswe umsinga we-zero-sequence ngaphakathi koluhlu oluthile, kukho imigaqo malunga nenani lee-transformers ezisebenza nge-neutral point esekwe.

Kwi-transformers ezisebenza ngaphandle kokumisa umhlaba, kufuneka kulungiselelwe ukhuseleko lwe-voltage olungenalandelelwano ukuze kuthintelwe umonakalo we-overvoltage kwi-transformer obangelwa zii-gap arcs kwiindawo zokuphosa ngexesha lokuphosa umhlaba.

Ngenxa yenqanaba eliphezulu lokwambathisa indawo engathathi cala yetransformer efakwe ngokupheleleyo, xa kuvela impazamo yomhlaba kwinkqubo, ukhuseleko lwangoku lwe-zero-sequence luya kuqala lunqumle itransformer enenqaku elingathathi cala elisekelwe phantsi, kwaye ukuba impazamo isekhona, kuya kubakho ukhuselo lwe-zero-sequence voltage lokunqumla inqaku elingathathi cala ngaphandle kokufaka isiseko kwitransformer.

(3) Ingongoma engathathi cala isekelwe kumsantsa wokukhupha

Iitransformer ze-Ultra-high zonke ziitransformer ezifakwe i-semi-insulation, kwaye i-insulation ye-neutral point coil emhlabeni ibuthathaka kunezinye iindawo. I-neutral point insulation isengozini yokwaphuka. Ke ngoko, kufuneka kulungiselelwe ukhuseleko lwe-gap.

Umsebenzi wokukhusela isithuba kukukhusela ukhuseleko lokufakelwa kwe-insulation ye-neutral point ye-transformer engenamhlaba engathathi cala.

Faka umsantsa wokuqhekeka phakathi kwendawo engathathi cala yetransformer nomhlaba njengoko kubonisiwe kumfanekiso. Xa iswitshi yokuzihlukanisa yokumisa umhlaba ivaliwe, itransformer imiswa ngokuthe ngqo kwaye ukhuseleko lwe-overcurrent olungenalandelelwano lusetyenziswa. Xa iswitshi yokuzihlukanisa yokumisa umhlaba isusiwe, itransformer imiswa ngesithuba ize ifakwe kwisikhuseli sesithuba.

Ukhuseleko lwesithuba lufumaneka ngokusebenzisa i-gap current 3I0 ehamba kwindawo engathathi cala ye-transformer kunye ne-bus PT opening triangle voltage 3U0 njengemigangatho.

Ukuba i-neutral point iphakanyisiwe ngenxa yempazamo, i-gap iyaqhekeka kwaye kuvela i-gap current enkulu ye-3I0. Ngeli xesha, ukhuseleko lwe-gap luyasebenza kwaye i-transformer iyanqunyulwa emva kokulibaziseka. Ukongeza, xa kuvela i-grounding failure kwinkqubo, ukhuseleko lwe-zero-sequence lwe-neutral point grounding transformer luyasebenza, kwaye i-neutral point grounding transformer iyanqunyulwa kuqala. Emva kokuba inkqubo ilahlekelwe yi-grounding point, ukuba i-failure isakhona, i-open triangle voltage ye-3U0 yebhasi ye-PT iya kuba nkulu kakhulu, kwaye ukhuseleko lwe-gap luya kusebenza ngeli xesha.