Ukukhetha Nokuvikela Ukucushwa Kokulungiswa Kwezindlela Zokumisa I-Transformer Engaguquki Ene-110kV

Isingeniso

Ezinhlelweni zamandla ezinamandla aphezulu, indlela yokufaka isisekelo se-transformer engathathi hlangothi iyinto ebalulekile ethonya ukuphepha kwesistimu, ukuthembeka, kanye nokuzinza. Ezinhlelweni zamandla ze-110kV, ukukhetha indlela yokufaka isisekelo sesisekelo sendawo engathathi hlangothi kuthinta ngqo amazinga okushisa imishini, ukuvikelwa kwe-overvoltage, ukucushwa kokuvikelwa kokudluliselwa, kanye nokuthembeka kokunikezwa kwamandla. EShayina, izinhlelo ze-110kV zivame ukusebenzisa i- indlela yokusekela ephumelela kancane, lapho amanye amaphuzu angathathi hlangothi e-transformer ebekwe ngqo phansi kuyilapho amanye ehlala engasekelwe phansi, kuhloswe ukunciphisa imisinga ye-short-circuit yesigaba esisodwa ngenkathi kuvinjelwa izinsongo ze-overvoltage.

Lesi sihloko sihlaziya izici, izinzuzo, kanye nemikhawulo yezindlela ezahlukene zokufaka isisekelo se-transformer esingakhethi hlangothi esingu-110kV, sihlola amasu okulungiselela ukuvikela afanele, futhi siveza izitayela zentuthuko zesikhathi esizayo.

Izindlela Ezi-1 Eziyinhloko Zokubeka Isisekelo Sendawo Engathathi hlangothi Yama-Transformers angu-110kV

1.1 Ukumisa Okuqondile

Ukubeka phansi okuqondileibhekisela ekuxhumekeni okuqondile kwephuzu elingathathi hlangothi le-transformer nomhlaba. Le ndlela ilungisa ngempumelelo amandla ephuzu elingathathi hlangothi, iqinisekisa ukuthi ngesikhathi sephutha lomhlabathi lesigaba esisodwa, ukunyuka kwe-voltage yesigaba esingenaphutha akudluli izikhathi eziyi-1.4 kune-voltage yesigaba. Lokhu kusiza ukwehlisa izidingo zokufakelwa kwemishini nokunciphisa izindleko.

Kodwa-ke, inkinga enkulu ukuthi i-ground fault current ephezulu kakhulu yesigaba esisodwa(kufika kuzinkulungwane eziningana zama-ampere), okungathinta i-circuit breaker ephazamisa amandla kanye nokuqina kohlelo. Ngakho-ke, ukusekela okuqondile ngokuvamile kusetshenziswa ezinhlelweni ze-voltage eziyi-110kV kanye ne-voltage ephezulu lapho kudingeka khona ukususwa kwamaphutha ngokushesha.

1.2 Ukungathathi hlangothi Okungasekelwe Emhlabathini

Ku- uhlelo olungenasisekelo, iphuzu elingathathi hlangothi le-transformer livikelwe emhlabeni. Uma kwenzeka iphutha lomhlabathi lesigaba esisodwa, i-fault current incane kakhulu (ikakhulukazi i-capacitive current yesistimu), okuvumela uhlelo ukuthi luqhubeke nokusebenza isikhathi esifushane (ngokuvamile kufika emahoreni ama-2). Lokhu kuthuthukisa kakhulu ukuthembeka kokunikezwa kwamandla.

Kodwa-ke, ezinhlelweni ezingamboziwe, amaphutha omhlaba wesigaba esisodwa angabangela ukuthi i-voltage yesigaba esingenaphutha ikhuphukele ezingeni le-voltage yomugqa. Uma ukufakelwa kubuthakathaka, lokhu kungaholela ekuqhekekeni, kukhuphuke kube yiphutha lesigaba kuya kwesigaba. Ngaphezu kwalokho, ukufakwa kwe-arc okungapheli kungadala ama-overvoltage e-arc, ifinyelela izikhathi ezingu-3–3.5 kune-voltage yesigaba, okubangela usongo ekushiseni kwe-transformer.

1.3 Ukumisa umhlaba nge-Small Impedance

Ukuze kulinganiswe izinzuzo kanye nokungalungi kwezinhlelo zokumisa umhlabathi ngqo kanye nezinhlelo ezingamboziwe, indlela yokusekela i-impedancekuvame ukusetshenziswa. Lokhu kufaka phakathi ukugawulwa ngokusebenzisa ukumelana okuncane noma ukusabela okuncane.

• Ukumelana Okuncane Okuphansi: Ikhawulela ugesi wephutha kuma-ampere angamakhulu amaningana, inciphisa umthelela ohlelweni ngenkathi isenza kube lula ukusebenza kokuvikela okusheshayo. Le ndlela icindezela ama-overvoltage ngempumelelo futhi ifanele amanethiwekhi okusabalalisa asebenzisa ikhebula anama-current amakhulu e-capacitive.
• Ukusekela Okuncane Kokusabela: Ingavala ugesi wesistimu we-capacitive ngokusebenzisa ugesi we-inductive, inciphise amathuba okubuyela emuva kwe-arc. Le ndlela ivame ukubhekwa njengendlela yokufaka isisekelo ekhokhelwayo.

Ukufaka inhlabathi nge-impedance encane kuhlanganisa izinzuzo zezinhlelo eziqondile nezingenasisekelo, okunikeza ukucindezela kwe-overvoltage kanye nokuthembeka okuphezulu kokunikezwa kwamandla. Kusetshenziswa kabanzi ezinhlelweni ze-110kV, ikakhulukazi lezo ezine-capacitive currents ebalulekile noma ezidinga ikhwalithi ephezulu yamandla.

Ukucushwa Kokuvikelwa Oku-2 Kwamaphuzu Angathathi hlangothi E-Transformer angu-110kV

2.1 Izinsongo Zokusebenzisa Amandla Angaphezulu Kakhulu

Izinga lokufakwa kokushisa kwephuzu elingathathi hlangothi le-transformer elingu-110kV livame ukuba okufakwe ugesi omncane, ngesilinganiso se-voltage esimelana ne-standing kuphela ingxenye yesithathu yokuphela komugqa. Lokhu kwenza iphuzu elingathathi hlangothi libe sengozini yokulimala kwe-overvoltage. Izinhlobo eziyinhloko ze-overvoltage zifaka:

• Ukwanda Kwemvamisa Yamandla: Okuvela ekushintsheni komugqa, amasekethe amafushane angalingani, noma ukulahlekelwa umthwalo ngokuzumayo.
• Ukwanda kwamandla kagesi: Kubangelwa ukunyakaza okubangelwa ukusebenzisana phakathi kwezinto ezibangela ukuvuvukala kanye nezinto ezibangela ukuvuvukala ngesikhathi sokusebenza kwesistimu noma amaphutha.
• Ukushintsha i-Overvoltage: Okubangelwa ukuguqulwa kwamandla kazibuthe kanye ne-electrostatic ngesikhathi sokuvulwa noma ukuvalwa kwama-circuit breaker.
• Ugesi Ongaphezulu Kombani: Kubangelwa ukushaya kombani, okubonakala ngokuphakama okuphezulu kanye nobude besikhathi esifushane.

2.2 Amadivayisi Okuvikela Avamile

Ukuvikela iphuzu elingathathi hlangothi le-transformer, amadivayisi okuvikela alandelayo avame ukusetshenziswa:

• Izibambi Zokukhuphuka: Lokhu kunciphisa ugesi ongaphezulu kombani kanye nogesi ongaphezulu kokushintshana. Kodwa-ke, izithiyo zokuvimba ugesi ezijwayelekile zivame ukunganeli ezingeni eliphansi lokufakwa kokushisa kwama-110kV transformer neutral points, okwenza ukukhetha kube nzima.
• Izikhala Zokuhlukaniswa: Lokhu kuvikela imvamisa yamandla kanye nokwanda kwamandla kagesi. Uma kwenzeka ukudlula kwamandla kagesi, igebe liyaphuka, limise iphuzu elingathathi hlangothi ukuze kuncishiswe ukuphakama kwamandla kagesi. Inkinga ubunzima bokulungisa ibanga legebe ngokunembile, okungaholela ekungaxhumani kahle kokuvikela.
• Ukuxhumeka Okufanayo kwe-Surge Arrester kanye ne-Gap: Lena indlela yokuvikela esetshenziswa kabanzi. I-surge arrester iphatha i-lightning overvoltage, kuyilapho i-gap ibhekana ne-power frequency kanye ne-resonance overvoltages. I-gap iphinde ivikele i-surge arrester ekukhuphukeni kwe-power frequency overvoltages okungase kubangele ukwehluleka kwayo. Le ndlela inikeza izinzuzo ezengeziwe.

2.3 Ukucushwa Kokuvikelwa Kokudluliselwa

Ukuvikelwa kwe-relay kwe-110kV transformer neutral point kuhlanganisa kakhulu izici ezilandelayo:

• Ukuvikelwa Kwamanje Kwe-Zero-Sequence: Kuma-transformer asekelwe ngqo, ukuvikelwa kwamanje okulandelana kwe-zero kulungiselelwe ukususa ngokushesha amaphutha omhlaba. Ukuvikelwa kuvame ukuhlukaniswa ngezigaba, kanye nokubambezeleka kwesikhathi esifushane kokuthola indawo yamaphutha kanye nokubambezeleka kwesikhathi eside kokukhubeka kuzo zonke izinhlangothi ze-transformer.
• Ukuvikelwa Kwe-Voltage Ye-Zero-Sequence kanye Nokuvikelwa Kwamanje Kwe-Gap: Kuma-transformer angaguquki, kusetshenziswa ukuvikelwa kwe-voltage ye-zero-sequence kanye nokuvikelwa kwe-gap current. Uma iphutha lomhlabathi libangela ukuthi uhlelo lulahlekelwe yi-ground point yalo, okuholela ekukhuphukeni kwe-voltage ye-neutral point, i-gap iyaphuka. Ukuvikelwa kwe-Gap current noma ukuvikelwa kwe-voltage ye-zero-sequence kusebenza ngokubambezeleka kwesikhathi (0.3–0.5s) ukuze kuphazamise i-transformer kuzo zonke izinhlangothi.
• Ukuhlanganiswa Kokuvikelwa Kokusekelayo: Ukuqinisekisa ukukhetha, ukulibaziseka kwesikhathi sokuvikela okulandelanayo okungenalutho kumele kuhlanganiswe. Isibonelo, ukulibaziseka kwesikhathi sokuvikela isipele ku-transformer kufanele kube isikhathi eside kunokuvikela komugqa ekusekelayo.

3 Izincomo Zokwenza Kusebenze Kahle Nokuhlaziywa Kwecala

3.1 Imikhawulo Yezindlela Zendabuko

Ngesikhathi ukusetshenziswa kwe izithiyo zokuvimba ukukhuphuka kwentaba zihambisana nezikhalakuvamile, le ndlela inezinkinga eziningana:

• Ubunzima Ekukhetheni I-Surge Arrester: Kuyinselele ukuthola izithiyo zokuvimba ukukhuphuka ezijwayelekile ezihlangabezana nezidingo ze-voltage ephezulu yokusebenza eqhubekayo kanye ne-voltage ephansi ye-lightning impulse yama-neutral points angu-110kV.
• Izinselele Ekubekeni Izikhala: I-voltage yokuqhekeka kwegebe lomoya ingaphansi kokuhlakazeka, okwenza kube nzima ukuxhumanisa ngokunembile ukusebenza kwegebe kwezimo zamaphutha "zokulahlekelwa komhlabathi" kanye "nenhlabathi".
• Ubunzima Bokuvikelwa Kwereyi: Ukuvikelwa "ekulahlekelweni komhlabathi" (njengokudlulela kwe-zero-sequence kanye nokuvikelwa kwe-gap overcurrent) kungase kungasebenzi kahle, kudingeke izindlela ezengeziwe zokuvimba, okwandisa ubunzima futhi kunciphisa ukuthembeka.

3.2 Izinzuzo Zokumisa Inhlabathi Ngokusabela Okuncane

Ucwaningo kanye nomkhuba kubonisa ukuthi ukusekela iphuzu elingathathi hlangothi nge-reactance encaneinikeza izinzuzo ezibalulekile kunezindlela zendabuko zokumisa ingxenye:

• Izidingo Zezinga Lokushisisa Ezincishisiwe: Ngemva kokusebenzisa isisekelo esincane sokuphendula, izinga lokufakwa kokushisa kwephuzu elingathathi hlangothi le-transformer lingancishiswa kusuka ku-35kV kuya ku-20kV, okuzosusa isidingo sezithiyo zokuvimba ukukhuphuka kanye nezikhala futhi kube lula ukucushwa kokuvikela.
• Imodi Yokumisa Ehlanganisiwe: Le ndlela iqeda ukwenzeka kohlelo oluzimele olungenasisekelo, okuvumela ukulula noma ukushiywa kwesivikelo esihlobene, ngaleyo ndlela kuthuthukisa ukuthembeka.
• Ukugcinwa Kwezinzuzo: Igcina izinzuzo zokufakwa kwesisekelo okungaphelele, njengokuvikelwa okulula nokuthembekile kwe-zero-sequence, ngenkathi ikhawulela amaza okujikeleza okufushane kwesigaba esisodwa.

3.3 Ukuhlaziywa Kwesifundo Secala

Isibonelo ukuguqulwa kwesiteshi esincane se-terminal esingu-110kV. Umklamo wokuqala wasebenzisa i- isivimbeli sokukhuphuka kwentaba esihambisana nesikhalaukuvikela iphuzu elingathathi hlangothi. Kodwa-ke, ngemva kokusebenzisa isisekelo esincane sokuphendula, isidingo sezinga lokufakwa kwe-transformer iphuzu elingathathi hlangothi sancishiswa, amadivayisi okuvikela enziwa lula, futhi ukuthembeka kokusebenza kwathuthukiswa. Izibalo zibonise ukuthi ukumelana komhlabathi kungakhawulela ugesi wephutha ube ama-ampere angamakhulu ambalwa, futhi ukuvikelwa kwe-zero-sequence kungahlanganiswa kalula.

Elinye icala lalihilela iphutha esiteshini esincane esingu-110kV lapho iphutha lomhlabathi lesigaba esisodwa elidlulayo emugqeni ongenayo laholela ekuqhekekeni kwegebe lamaphuzu angathathi hlangothi kanye nokukhubeka kwe-transformer. Ukuhlaziywa kwembule ukuthi nakuba iphutha lomugqa lalidlula, impendulo evela enanini elikhulu lama-motor asynchronousohlangothini lomthwalo kunikeze amandla e-arc, okusekela iphutha. Lokhu kugcizelela ukuthi kuma-transformer anemithwalo emikhulu yemoto (imithombo elinganayo), ukuvikelwa okuphelele kwephuzu elingathathi hlangothi, okuhlanganisa umkhawulo wamandla okulandelana kwe-zero-sequence, umkhawulo wamandla okungena, kanye nokuvikelwa kwe-zero-sequence voltage, kubalulekile ngesikhathi sesigaba sokuklama.

4 Isiphetho kanye Nombono

Ukukhethwa kwendlela yokumisa isisekelo se-transformer engu-110kV kanye nokucushwa kwayo kokuvikela kuwumsebenzi onezici eziningi odinga ukucatshangelwa kwesakhiwo sesistimu, izici zomthwalo, kanye nezidingo zokuthembeka. Nakuba indlela yendabuko yokumisa isisekelo engaphelele ehlanganiswe nezithiyo zokuvimba ukukhuphuka kanye nezikhala ivamile, ibhekene nezinselele ekukhetheni nasekuhleleni idivayisi. indlela yokusekela yokusabela okuncaneinikeza enye indlela ethembisayo, okungenzeka yehlise izidingo zokuvikela ukushisa, yenza lula ukuvikelwa, futhi ithuthukise ukuthembeka.

Izitayela zentuthuko yesikhathi esizayo zizogxila kulezi zindawo ezilandelayo:

• Ukusetshenziswa Kwamadivayisi Amasha: Njengezikhala ezihlanganisiwe noma izikhala ezingalawuleki ezisetshenziswa kanye nezithiyo zokuvimba ukukhuphuka, okuthuthukisa ukuthembeka nokunemba kokuvikela.
• Ubuchwepheshe Bokuvikela Idijithali: Ukusebenzisa ukuvikelwa okusekelwe kuma-microcomputer ngama-algorithms athuthukile (isb., ukuhlonza i-waveform, ukuhlaziywa kwe-harmonic) ukuthuthukisa ukuzwela nokuthembeka kokuvikelwa kwamaphutha omhlaba.
• Ukumiswa kanye nokuguqulwa: Ukuthuthukisa imishini yokuvikela amaphuzu angathathi hlangothi nejwayelekile ukuze kube lula ukuklama nokunakekela.

Ngamafuphi, ukwenza ngcono indlela yokumisa isisekelo se-transformer engu-110kV neutral point kanye nokucushwa kokuvikela kubalulekile ekuthuthukiseni ukuphepha, ukuthembeka, kanye nokusebenza komnotho kohlelo lwamandla. Ngokuthuthuka kwezobuchwepheshe, kulindeleke ukuthi kuvele izixazululo ezihlakaniphile nezisebenzayo futhi zisetshenziswe kabanzi.