Indlela Yokuvikela Ama-Transformer. indlela efanele yokuvikela ama-transformer ingahlala isikhathi eside.

I-transformer iyimishini engaguquki esebenza njalo, isebenza ngokuthembeka okukhulu, amathuba amancane okwehluleka. Kodwa ngenxa yokuthi iningi lama-transformer afakwa ngaphandle, futhi athintwa umthwalo ngesikhathi sokusebenza kanye nomthelela wephutha le-short circuit yesistimu yamandla, amaphutha ahlukahlukene kanye nezimo ezingavamile akunakugwenywa enkambisweni yokusebenza.

1. Amaphutha avamile kanye nokungafani kwama-transformer

Amaphutha e-transformer angahlukaniswa ngamaphutha angaphakathi kanye namaphutha angaphandle.

Amaphutha angaphakathi abhekisela kumaphutha ayenzeka ngaphakathi kwekesi, njengezinkinga ze-inter-phase short-circuit of windings, amaphutha e-inter-turn short-circuit of one-phase windings, amaphutha e-short-circuit phakathi kwe-windings kanye ne-iron core, kanye namaphutha okunqamula i-windings, njll.

Amaphutha angaphandle abhekisela kumaphutha ahlukahlukene esigaba esifushane phakathi kwemigqa yangaphandle ye-lead yama-transformer kanye namaphutha okusekela phansi esigaba esisodwa okwenzeka lapho i-insulation bush ye-lead line idlula ebhokisini.

Ukwehluleka kwe-transformer kwenza umonakalo omkhulu. Ikakhulukazi uma kwenzeka iphutha langaphakathi, i-arc yokushisa ephezulu ekhiqizwa ugesi we-short-circuit ngeke nje ishise i-insulation kanye ne-iron core ye-transformer winding, kodwa futhi ibangele ukuthi uwoyela we-transformer ubole futhi ukhiqize igesi eningi, okuholela ekuguqukeni kwegobolondo le-transformer ngisho nokuqhuma. Ngakho-ke, lapho i-transformer yehluleka, kumele isuswe.

Ukuphazamiseka kwe-transformer ikakhulukazi ukugcwala ngokweqile, ukwehla kwezinga likawoyela, i-short circuit yangaphandle ebangelwa ukugcwala ngokweqile, izinga lokushisa likawoyela we-transformer elisebenza liphezulu kakhulu, izinga lokushisa lokugoba liphezulu kakhulu, ingcindezi ye-transformer iphezulu kakhulu, kanye nokwehluleka kwesistimu yokupholisa. Uma i-transformer ingajwayelekile, kufanele kunikezwe isignali ye-alamu.

Okwesibili, ukucushwa kokuvikelwa kwe-transformer

Ukuvikelwa okuyinhloko kwephutha le-short circuit: ukuvikelwa kokwehluka kwe-longitudinal, ukuvikelwa kwegesi esindayo, njll.

Ukuvikelwa kokusekelayo kwamaphutha e-short circuit: ikakhulukazi ukuvikelwa kokudlula kwamandla kagesi okuhlanganisiwe, ukuvikelwa kokulandelana kwe-zero (isiqondiso) kokudlula kwamandla kagesi, ukuvikelwa kokuphazamiseka okuphansi kwe-impedance, njll.

Ukuvikelwa kokusebenza okungavamile: ikakhulukazi ukuvikelwa komthwalo osindayo, ukuvikelwa kokuvusa ngokweqile, ukuvikelwa kwegesi elula, ukuvikelwa kwegebe elingathathi hlangothi, izinga likawoyela lokushisa kanye nokuvikelwa kokuhluleka kohlelo lokupholisa.

Okwesithathu, ukuvikelwa okungekona kukagesi

Isivikelo se-transformer esakhiwe ngowoyela, igesi, izinga lokushisa kanye nomthamo ongewona ugesi sibizwa ngokuthi isivikelo esingewona ugesi. Ngokuyinhloko kukhona isivikelo segesi, isivikelo sokucindezela, isivikelo sokushisa, isivikelo sezinga likawoyela kanye nesivikelo sokuma esipholile. Isivikelo esingewona ugesi sisebenza njengoba kudingeka endaweni ukuze kukhubeke noma kuthunyelwe izimpawu.

1. Ukuvikelwa kwegesi

Uma i-transformer yangaphakathi ihluleka, ngenxa yendima ye-short-circuit current kanye ne-short-circuit point arc, i-transformer yangaphakathi izokhiqiza igesi eningi, ngesikhathi esifanayo ijubane lokugeleza kukawoyela we-transformer, ukusetshenziswa kwegesi kanye nokugeleza kukawoyela ukufeza ukuvikelwa kubizwa ngokuthi ukuvikelwa kwegesi.

(1) Ukuvikelwa kwegesi elincane: lapho kwenzeka iphutha elincane noma ukungahambi kahle ngaphakathi kwe-transformer, ukushisa ngokweqile kwendawo yephutha kubangela ukwanda kwengxenye kawoyela, futhi igesi ekopheni yakha amabhamuza bese ingena ku-relay yegesi. Isenzo sokuvikelwa kwegesi elincane sithumela isignali yegesi elincane.

(2) Ukuvikelwa kwegesi esindayo: lapho kwenzeka iphutha elikhulu ethangini le-transformer, ugesi wephutha uba mkhulu, futhi i-arc ibangela ukuthi uwoyela we-transformer ubole ngobuningi, okuholela ekugelezeni okukhulu kwegesi namafutha. Ukuphazamiseka komthelela kwenza igesi esindayo ilandele isenzo sokuvikela, ithumele isignali yegesi esindayo kanye nohambo lokuphuma, bese i-transformer inqanyulwa.

(3) Ukuvikelwa kwegesi esindayo kuyisivikelo esiyinhloko sokwehluleka kwangaphakathi kwethangi likaphethiloli, okungabonisa ukwehluleka okuhlukahlukene kwangaphakathi kwe-transformer. Uma i-transformer ifika, kujika okumbalwa ukuze kuphenduke i-short circuit, yize ugesi wephutha mkhulu kakhulu, kodwa ekuvikelweni kokungafani okukhiqizwa ugesi we-differential kungase kungabi mkhulu, ukuvikelwa kokungafani kungase kwenqabe ukusebenza. Ngakho-ke, ngamaphutha angaphakathi e-transformer, kuyadingeka ukuthembela ekuvikelweni kwegesi esindayo ukuze kususwe amaphutha.

Isithombe

2, ukuvikelwa kwengcindezi

Ukuvikelwa kwengcindezi nakho kuyisivikelo esiyinhloko emaphutheni angaphakathi ethangi le-transformer. Ngokukhululwa kwengcindezi kanye nokuvikelwa kokuguqulwa kwengcindezi, kusetshenziswa ukukhombisa ingcindezi kawoyela we-transformer.

3, ukuvikelwa kwezinga lokushisa kanye namafutha

Uma izinga lokushisa le-transformer lenyuka lifinyelela enanini lesixwayiso, isivikelo sokushisa sithumela isignali ye-alamu bese siqala i-standby cooler.

Uma i-transformer ivuza uwoyela noma yehlisa izinga likawoyela ngezinye izizathu, izinga likawoyela liyavikelwa bese kuthunyelwa isignali ye-alamu.

4, ukuvikelwa kokuma konke okupholile

Uma wonke ama-cooler e-transformer esebenza eyeka, izinga lokushisa le-transformer lizokhuphuka. Uma lingaphathwanga ngesikhathi, ukufudumala kwe-transformer winding kungase konakale. Ngakho-ke, lapho wonke ama-cooler ema ekusebenzeni kwe-transformer, isivikelo sithumela isignali ye-alamu futhi sikhiphe i-transformer ngemva kokulibaziseka isikhathi eside.

Okwesine, ukuvikelwa okuhlukile

Ukuvikelwa komehluko we-transformer kuyisivikelo esiyinhloko somthamo kagesi we-transformer, futhi ububanzi bawo bokuvikelwa yingxenye ezungezwe yi-transformer yamanje ohlangothini ngalunye. Kulolu hlu kwenzeka phakathi kwesekethe esifushane, isekethe esifushane esiphakathi kokujika kanye nezinye izinkinga, isivikelo somehluko esenzweni.

1, i-transformer inrush yamanje

Ugesi wensimu okhiqizwa lapho i-transformer iwa ubizwa ngokuthi ugesi we-field inrush. Usayizi wogesi we-inrush ovusa inkanuko uhlobene nesakhiwo se-transformer, i-Angle yokuvala, umthamo, i-remanence ngaphambi kokuvala nezinye izici. Ukulinganisa kukhombisa ukuthi ugesi we-inrush uvame ukuba izikhathi ezingu-2 ~ 6 zamandla alinganisiwe, kanti umkhawulo ungaphezu kwezikhathi ezingu-8 zamandla alinganisiwe. Ngenxa yokuthi ugesi we-inrush ugeleza kuphela ku-transformer ohlangothini lokushaja, uzokhiqiza ugesi omkhulu ohlukile ku-differential loop, okuholela ekusebenzeni kabi kokuvikelwa komehluko.

Umsinga wokungena unezici ezilandelayo: a. Inani lomsinga wokungena likhulu kakhulu futhi liqukethe ingxenye ecacile ye-aperiodic; B. I-waveform iqondile futhi ayiqhubeki; C, iqukethe ingxenye ecacile ye-harmonic ephezulu, ikakhulukazi ingxenye yesibili ye-harmonic; D. Umsinga wokungena wokungena uyancishiswa.

Ngokwezici ezingenhla zamandla okungena, ukuze kuvinjelwe amandla okungena ekubangeni ukusebenza kabi kokuvikelwa komehluko we-transformer, iphrojekthi isebenzisa izimiso ezintathu: okuqukethwe okuphezulu kwesibili kwe-harmonic, ukungalingani kwesimo samagagasi, ukungaguquki kwesimo samagagasi I-Engela ukuze kutholakale ukukhiya kokuvikelwa komehluko.

2. Isimiso sesibili sokubhuleka kwe-harmonic

Ingqikithi yokubhuleka kwe-harmonic yesibili ukusebenzisa ingxenye yesibili ye-harmonic yamanje ohlukile ukuze kuhlulelwe ukuthi i-differential current iyi-fault current noma i-inrush current. Uma iphesenti le-harmonic yesibili engxenyeni eyisisekelo inkulu kunenani elithile (ngokuvamile i-20%), i-differential current ibhekwa njengebangelwa yi-inrush current, futhi ukuvikelwa kwe-differential kuvaliwe.

Ngakho-ke, uma isilinganiso sesibili sokubhuleka kwe-harmonic sikhulu, kulapho ugesi wesibili we-harmonic oqukethwe kugagasi eliyisisekelo elivunyelwe ukhulu khona, futhi umphumela wokubhuleka uba mubi kakhulu.

3, ukuvikelwa kokuphuka okusheshayo okuhlukile

Uma kwenzeka iphutha elikhulu ngaphakathi kwe-transformer futhi i-fault current inkulu ngokwanele ukuholela ekugcwalisweni kwe-CT, i-CT secondary current nayo iqukethe inani elikhulu lezingxenye ze-harmonic. Ngokusho kwencazelo engenhla, kungenzeka ukuthi i-differential protection izokhiywa noma ibambezeleke ngenxa ye-harmonic braking yesibili. Lokhu kuzolimaza kakhulu i-transformer. Ukuze kuxazululwe le nkinga, i-differential quick-break protection ivame ukusethwa.

I-Differential quick-break element empeleni iyisici sokwehluka esingaguquki sokuvikelwa kokwehluka okude. Ngokungafani ne-general differential element, ikhombisa inani elisebenzayo lokugeleza kokwehluka. Kungakhathaliseki ukuthi i-waveform yokugeleza kokwehluka ingakanani, ukuthi usayizi we-harmonic component ungakanani, uma nje inani elisebenzayo lokugeleza kokwehluka lidlula inani lokusetha lokuphuka kwejubane lokwehluka (ngokuvamile liphakeme kunenani lokusetha lokuvikelwa kokwehluka), izosusa ngokushesha i-transformer, ngaphandle kokukhiya kwamanje kwe-inrush kanye nezinye izindlela.

Ezinhlanu, ukuvikelwa kwesipele se-transformer

Ukuvikelwa okuyinhloko kwe-transformer kwethulwa kafushane, futhi ukuvikelwa kokusekelayo kwe-transformer kuyaqhubeka kwethulwa. Kunezinhlobo eziningi zokulungiswa kokuvikelwa kokusekelayo kwama-transformer. Lapha, sethula kafushane izinhlobo ezimbili zokuvikelwa kokusekelayo kwe-transformer, okuwukuvikelwa kokudlula kwamandla kagesi okukhiya kabili kanye nokuvikelwa komhlabathi.

1, ukukhiya okuphindwe kabili kokucindezela phezu kokuvikelwa kwamanje

Ukuvikelwa kokudlula komsinga we-voltage okuhlanganisiwe kuyisivikelo sokusekelayo sephutha le-short circuit phakathi kwama-transformer amakhulu naphakathi. Kufanelekela ama-transformer akhuphukayo, ama-transformer oxhumano lwesistimu kanye nama-transformer akhuphukayo ukuvikelwa kwawo kokudlula komsinga akukwazi ukuhlangabezana nezidingo zokuzwela. I-voltage ehlanganisiwe eyakhiwe yi-voltage yokulandelana okungalungile kanye ne-voltage ephansi ingabonisa amaphutha ahlukahlukene ebangeni lokuvikela, inciphise inani lokusetha lokuvikelwa kokudlula komsinga, futhi ithuthukise ukuzwela.

Ukuvikelwa kokushisa okuphezulu kwamandla kagesi ahlanganisiwe kwakhiwe yi-compound voltage element, i-overcurrent element kanye ne-time element. Ukushisa okuphezulu kwamandla kagesi okuvikelayo yi-secondary SIGABA ESITHATHU CT current ohlangothini lwendawo lwe-transformer, kanti i-access voltage yi-secondary three-phase PT voltage ohlangothini lwendawo noma kwezinye izinhlangothi ze-transformer. Ukuze kuvikelwe i-microcomputer, i-voltage yalolu hlangothi inganikezwa kwezinye izinhlangothi ngesofthiwe, ukuqinisekisa ukuthi noma yiluphi uhlangothi lokugcinwa kwe-PT, lusakwazi ukusebenzisa ukuvikelwa kokushisa okuphezulu kwamandla kagesi ayinkimbinkimbi. I-action logic iboniswe ngezansi.

2, ukuvikelwa kokumisa isisekelo se-transformer

Ukuvikelwa kokusekelayo kwephutha le-grounding short circuit ye-transformer enkulu nephakathi ngokuvamile: ukuvikelwa kwe-zero sequence overcurrent, ukuvikelwa kwe-zero sequence overvoltage, ukuvikelwa kwegebe njalo njalo. Okulandelayo isingeniso esifushane sezindlela ezintathu ezahlukene ze-grounding ezisekelwe endaweni engathathi hlangothi.

(1) Iphuzu elingathathi hlangothi lisekelwe ngqo

Kuma-transformer ane-voltage engu-110kV futhi ngaphezu kwephuzu elingathathi hlangothi elisekelwe ngqo, ukuvikelwa kwamanje okulandelana okungu-zero kufanele kubekwe eceleni kohlelo lokumisa ugesi oluphezulu ukuze kuboniswe iphutha lokumisa ugesi. Kuma-transformer asekelwe ngqo ezinhlangothini zombili eziphakeme neziphakathi, ukuvikelwa kwamanje okulandelana okungu-zero kufanele kube sendleleni yebhasi ngalinye eliseceleni.

Isimiso sokuvikelwa kwamanje okulandelana okungu-zero sifana nesokuvikelwa kokulandelana okungu-line zero, bheka udaba 30. Umugqa wokulandelana okungu-zero ungatholakala kumugqa wesibili we-CT wephuzu elingathathi hlangothi, noma kumugqa wesibili we-CT wesigaba sesithathu ohlangothini lwendawo. Umugqa wokulandelana ongu-zero oxhunywe kwisici esiqondisayo ungatholakala ku-voltage yokuvula unxantathu we-PT ohlangothini lwendawo noma ku-voltage yesibili yesigaba sesithathu ohlangothini lwendawo. Kudivayisi yokuvikela i-microcomputer, ikakhulukazi sebenzisa indlela ekhiqizwayo.

Kuma-transformer amakhulu anama-twing amathathu, ukuvikelwa kwamanje okulandelana kwe-zero kungaba yizigaba ezintathu. Kukhona isiqondiso esigabeni I kanye ne-II, futhi akukho isiqondiso esigabeni III. Isigaba ngasinye ngokuvamile sinokulibaziseka kwezigaba ezimbili, ngokubambezeleka okufushane kokunciphisa ububanzi bephutha (ibhasi lokuxhuma noma iswishi lendawo), nokubambezeleka okude kokususa i-transformer (iswishi yokuxhuma yezinhlangothi ezintathu). Ukucushwa kokuvikelwa okuqondile kuncike esimweni sangempela.

Njengoba kuboniswe esithombeni, ngemva kokusebenza kokuvikelwa kwamanje kwesiqondiso se-zero-sequence esigabeni I noma II, ibhasi le-t1 noma le-T3 noma iswishi yendawo enokulibaziseka okufushane kufanele igxunyekwe kuqala ukuze kuncishiswe ububanzi bethonya lephutha. Uma inani lephutha lisekhona, i-transformer kufanele inqunywe ngeswishi yezindlela ezintathu ye-t2 noma ye-T4 ngokulibaziseka okude. Isigaba III ngaphandle kwesiqondiso, i-transformer isuswa ngqo ngokulibaziseka.

(2) iphuzu elingathathi hlangothi alisekelwe

Umugqa we-zero sequence udlula endaweni engathathi hlangothi ye-transformer ukuze wakhe i-zero sequence loop. Kodwa-ke, uma wonke amaphuzu angathathi hlangothi e-transformer ephansi, umugqa we-short-circuit endaweni yokuphansi uzosatshalaliswa ku-transformer ngayinye, okuzobangela ukuthi ukuzwela kokuvikelwa komugqa we-zero-sequence overcurrent kunciphe. Ngakho-ke, ukuze kukhawulelwe umugqa we-zero-sequence ebangeni elithile, inani lama-transformer aphansi endaweni engathathi hlangothi liyalawulwa.

Ku-transformer engaguquki, kufanele kulungiselelwe ukuvikelwa kwe-voltage ye-zero-sequence ukuze kuvinjelwe umonakalo we-transformer obangelwa yi-gap arc endaweni yephutha lapho kwenzeka iphutha lokufaka isisekelo.

I-transformer evikelwe ngokuphelele ngenxa yezinga layo eliphezulu lokuvikela iphuzu elingathathi hlangothi, lapho uhlelo luvela iphutha lokumisa, isivikelo sokuqala samanje se-zero-sequence ukususa i-transformer ye-grounding ye-neutral point, uma iphutha lisakhona, bese kuba isivikelo se-voltage se-zero-sequence ukususa i-transformer ye-neutral point ungrounded.

(3) Iphuzu elingathathi hlangothi lisekelwe ngegebe lokukhipha

Zonke iziguquli ze-hV zifakwe ugesi kancane, futhi ugesi we-coil engathathi hlangothi emhlabathini ubuthakathaka kunezinye izingxenye. Ugesi ongathathi hlangothi uvame ukuphuka. Ngakho-ke, udinga ukumisa ukuvikelwa kokususwa kwegesi.

Indima yokuvikela igebe ukuvikela iphuzu elingathathi hlangothi lokuphepha kokufakwa kwe-transformer engaguquki.

Njengoba kuboniswe, kufakwa igebe lokuqhekeka phakathi kwephuzu elingathathi hlangothi le-transformer nomhlabathi. Lapho iswishi yokuhlukanisa umhlaba ivaliwe, i-transformer ifakwa ngqo emhlabathini bese kufakwa isivikelo sokulandelana kwe-zero sequence overcurrent. Lapho iswishi yokuhlukanisa umhlabathi inqanyuliwe, i-transformer ifakwa phansi phakathi kwegebe bese ifakwa ekuvikelweni kwegebe.

Ukuvikelwa kwegebe kutholakala ngokusebenzisa igebe lamanje elingu-3I0 eligeleza endaweni engathathi hlangothi ye-transformer kanye ne-voltage yonxantathu ovulekile engu-3U0 yebhasi i-PT njengesici.

Uma iphuzu elingathathi hlangothi endaweni yephutha liphakanyisiwe, ukuqhekeka kwegebe, okuholela ku-gap current enkulu engu-3I0, ngalesi sikhathi, isenzo sokuvikela igebe, ngemva kokubambezeleka kokususa i-transformer. Ngaphezu kwalokho, lapho uhlelo lunephutha lokumisa isisekelo, ukusebenza kwe-grounding point okungathathi hlangothi kwe-transformer akunalo isenzo sokuvikela ukulandelana, kuqala usike i-grounding grounding transformer engathathi hlangothi. Ngemva kokuba uhlelo lulahlekelwe iphuzu lomhlabathi, uma iphutha lisakhona, i-voltage evulekile kanxantathu yebhasi i-PT 3U0 izoba nkulu, futhi ukuvikelwa kwegebe kuzosebenza ngalesi sikhathi.

Umthombo: Ipulpiti yamandla