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Izinkaliso Zokuvikela Ezibalulekile Zomthwalo we-PV Circuit Breaker
Ukuvikela kwe-overcurrent ne-short-circuits ngokusebenzisa ukuthunywa kwe-thermal-magnetic
Isikhiphi sesifunda se-PV sinesistimu ephindwe kabili ye-thermal-magnetic, engasabela ekulayisheni ngokweqile kwesikhathi eside kanye nokwehluleka okungazelelwe kwesikhathi esifushane. Ngokwesibonelo, uma kunamandla amaningi kakhulu adlula ohlelweni isikhathi eside kakhulu, esimweni sephaneli elihlaselwe ukukhanya kwelanga okunamandla kakhulu, ingxenye yokushisa yesivimbeli iqala ukuphazamiseka kwesifunda ngokugoba nokuqhekeza umucu wensimbi. Ngakolunye uhlangothi, ingxenye kazibuthe yesivimbeli isabela uma kunenkinga futhi amandla adlula amanani avamile uhlelo olwenzelwe wona, futhi kulokhu, amandla adlula inani elijwayelekile ngokuphindwe kathathu. Isikhonkwane sikagesi siyogxilisa futhi siphule oxhumana nabo besekethe ngendlela yokuthi ngeke kube khona imisinga yamaphutha ekwazi ukugeleza ngendlela engaphephile ephutheni. Lokhu kusabela okusheshayo kuzovimbela ukulimala kwe-insulation, ukushisa ngokweqile, nemithombo yomlilo eduze nezinto ezivuthayo (kuhlanganise nezintambo ze-PV). Isici esiyinhloko sesiphazamisi ukuthi sihlukile kuma-fuse, njengoba singasethwa kabusha, okusho ukuthi iziphazamisi zingavuselelwa futhi zingasetshenziswa futhi okuzokwenza kulezi zinhlobo zezitshalo ze-PV kunciphise isikhathi sokuphumula kohlelo. Kulokhu, ama-PV breakers azuzisa kakhulu izitshalo ezinkulu zamandla kagesi we-PV, lapho isikhathi sokusebenza kwesistimu sibaluleke kakhulu.
Ukuphulula Umkhakha We-DC: Imiphumela YokuSebenzisa Ambrakeri Ase-Ac Okwesibini Emasistimini E-Photovoltaic
Amabreaker ase-AC asingasemthwakweni kuzinzinzani zase-PV ngoba akakwazi ukuphulula amaphepha ase-DC ngokuphelele. Umthelela wase-AC ungenza ngokuzenzakalela ku-zero ngamahora angu-100 ukuze a-120 ngomzuzu, okunika umphela kwe-maphhepha. Kuzinzinzani zase-DC, akukho kuchaza kwe-zero crossing, ngakho ke amaphepha ayiphela ngokwakhe. Ngempela, izifundo zibonisa ukuthi amabreaker ase-AC asingasemthwakweni kungcono kunezise-DC ngokubhekana nokuphinda kuvuka kwamaphepha: isilinganiso sesikhathi sokuphinda kuvuka ngu-78%. Amaphhepha athuluzi kungaba ne-temperature engu-6,000°F — iphakade ekufanele ukuthulula i-copper busbars. Lokhu kukuthi amabreaker ase-AC asingasemthwakweni kuzinzinzani zase-solar; kufuneka kubekwe amabreaker ase-DC kuphela, njengoko kubekwe amachute ase-arc. Amachute ase-arc abhekiswe ukuthi umphela wamaphhepha awusakhiwa kuphela ngeprinciples yase-electromagnetic repulsion, kodwa futhi ukuthi kubhekiswe ukuthi umphela wamaphhepha udluliswe ngaphezu kwalokho — ukuhliza kabusha ngaphambi kokuphinda kuvuka. Lokhu kuyisidingo sokuvikela ukuthi isikhalazo sivikeleke kuzinzinzani zase-utility-scale zase-600 ukuze a-1500 volts.
Ukuphatha Kwemithambo Yekhurukhenti Yezinkulungwane (DC): Sizinga Ukuthi Kwenzeni Ngokuthi Kuyisibonelo Sokugcina Isikhathi Sokubuyela Emva Kwesikhathi Sokugcina (Zero Crossing) Emakhurukhentini Ama-PV
Ukuthi I-PV Circuit Breakers Iyakuthintela Kanjani Ukuthi Kwenzeni Ukuthi Kuyizimithambo
Ngoba ikhurukhenti yezinkulungwane (DC) ayikho isikhathi sokugcina esinamandla, uma kwenzeni ubungozi, ikhurukhenti yezinkulungwane ibangela ukuthi kwenzeni izimithambo ezingavunyelwa, futhi ema-80% amashumi ayisikhombisa ukuthi kuyizimithambo ezingavunyelwa (NREL 2023). Izimithambo ziyakwenzela ukuthi izihlangothi zihlale zihlabeleka ngaphezulu kwe-3000 \degree Celsius, okwenza ukuthi kuyisibonelo sokuthi kuyisibhakabhaka sokufa ngomlilo. Ukuze sikubhekise lokhu, i-PV circuit breakers inama-phakathi amathile athiwa ngokuthi ngu-magnetic arc chutes, oqondisa umkhondo wokuthintela izimithambo, ukuhambisa kanye nokuhlisa izimithambo. Umphumela wokuthintela izimithambo ngokuthi kusetyenziswa umkhondo wokuthintela uyaphendula ngokuthi kuyakwenzeka ukuthi kwenzeni izimithambo ezincinci kanye nokuthintela izimithambo ngemizuzu eyisikhombisa. Lokhu kusinika ukuvikela phakathi kwesikhathi sokuhlanza kwezinhlobo zokusebenza zokhurukhenti yezinkulungwane (thermal runaway protection) nokuvikela ukusebenza kwezinhlobo zokhurukhenti yezinkulungwane ezihigh voltage.
Umbuzo owenziwe ngamakhurukhenti ayezinkulungwane (high voltage direct current - DC) kanye ne-circuit breakers
Njengoba amandla kagesi wesistimu ye-DC anda, kanjalo nokusebenza kahle kwezinhlelo ze-photovoltaic (PV), noma kunjalo, amandla ahambisana ne-arcing angenzeka nawo ayanda. Isibonelo, izinhlelo ze-1500V DC zingakhiqiza amandla okugoba aphindwe izikhathi ezingu-15 kunezinkqubo ze-400V DC. Lokhu kusinikeza inselele eyingqayizivele. Lapho ukusebenza kahle kukhulu, yilapho kudingeka sisheshe silungise iphutha, futhi yilapho kudingeka sisebenzise izinhlelo eziqinile. Ama-breakers wesekethe ye-PV anamuhla manje ayakwazi ukunciphisa lezi zinkinga, futhi izici ezintsha eziningana ezihlobene nokuhambisana ne-UL 2024 esizoxoxa ngazo manje, zinikeze amandla lobu buchwepheshe be-breaker ye-PV obuhlelwe kabusha.
Izikhathi zokuhamba ezisheshayo kakhulu (i-3ms noma ngaphansi) kanye nokucishwa kwe-arc okuhambisanayo (izikhala phakathi kokuxhumana kwe-breaker, kanye nama-chutes we-arc amaningi, aklanyelwe ukuthuthukisa ukucishwa kwe-arc lapho kuphazanyiswa isekethe).
Izilungiselelo zokuphuma kwemithombo ngokuhlanganisa ukulingana kwe-DC voltage nokukhulula kwe-arc zibuye zisuswene ukuze zihambane nevoltage esetyenziswa kusistimu.
Isifundo Sokuvikela 400V Isistimu 1500V Isistimu Ukuchaza Okuphelele
Isikhathi Sokuphuma 10ms ≤3ms Ukuhambisana Kwezikhathi Ngaphezu Kwesikhathi 70%
Amaphuzu Ophutha We-Arc 8 ku-10 15 ku-20 Amaphuzu Angaphezu Kwesikhathi 100%
Umgcobo Wokugxila 10mm 25mm Umgcobo Ongaphezu Kwesikhathi 150%
Lezi zilungiselelo zesistimu zizokunciphisa kakhulu noma zizokubeka phansi izinkinga zokuphuma kwemithombo—lokhu kukhombisa ukuthi kunezinkinga ezinamandla kusistimu sezivoltage ephakeme, okuzokubangela ukuthi kubhekwe amaphutha angaphezu kwesikhathi, nakwa kusukela emithombweni yezivoltage ephakeme ayiphume. Lokhu kusho futhi ukuthi imithombo yezivoltage ephakeme ayikwazi ukusebenza kusistimu sezivoltage ephakeme se-PV.
Ubudlelwano Bokuvikela Kwesitsha: Sizinga Ukubuka Kwamaphutha Amane Nokufa Kwesistimu Se-PV Esifanayo
Ukuthi kuyini ukuthi kubhekwe amaphutha amane lapho kubhekwe isibonelo noma kubhekwe ukungafani kwezithombe, futhi ukuthi kubhekwe njani ukuthi kubhekwe amaphutha amane ngokuphambuka ngokusebenzisa imithombo yezivoltage ephakeme ye-PV.
Kodwa kufana kwezinkampani zokugcina amaphaneli ase-Solar noma kubonakala ukungafanele kwezinkampani zokugcina (*parallel*) kunezinhlobo ezingavumelekile zezinhlobo zokusebenza kwemithombo. Ukuzingela ekusenyaneni esikodwa: Kuyadlula ngendlela engafani nezinye. Kuyadlula ngendlela yokukhupha imisebenzi ngaphandle kokuthenga. Umphumela wale ndlela yokuqhubeka kuyisibonelo sokuthi: imisebenzi eyodlula ngaphansi kuyenza loyo isibonelo sokuthi *isikhumba esikhulu*. Lokhu kuyisibonelo esingasemthwakweni kakhulu kwezinkampani zokugcina amaphaneli ase-PV futhi kuyaziwa kakhulu ukuthi kuyenza ukuthi izinkampani zokugcina ziyodlula ngaphansi kwezinkampani zokugcina ezikodwa. Uma kungabonakalwa, umphumela wokungafanele kwezinkampani ezikodwa kungahlela kwezinhlobo zokungafanele zokugcina zonke. Le ndlela yokuqhubeka kuyatholakala kakhulu embonini. Umgca wase-NREL owayishicilela ngo-2023 wabonisa ukuthi izindlela zokuthengisa iziphumo zokungafanele kwezinkampani zokugcina amaphaneli ase-PV kungaba kude kakhulu kunezindlela zokuthengisa iziphumo zokungafanele zokugcina zonke. Lokhu kuyisibonelo esikhulu sokuthi indlela yokuthengisa kungahlela kwezinhlobo zokungafanele kakhulu.
Ambrakeri we-PV ayafunda izinkinga futhi azenze ukuthi zingaphumeleli ngokufunda indlela yocurrent. Uma icurrent esebenzayo iphinda kude kwe-10% yekhwalifikeyishini yestring, amasensha amathembekile okuphakamisa amagwinya aphume ngemizuzwana emibili futhi abulawa umthelela wamandla kusenzo esibi ngaphandle kokuthi isisipho sokusebenza sikhona. Ngaphezu kwalokho, lezi brakeri zinezindawo zokubhala ezithile ezibhala umthwalo wokubhala futhi zihlale umthwalo wokubhala ngaphandle kwesibhakabhaka, kuvikela ukuthi kungabhekwa umplasma wokusebenza kwe-DC oya kwenza umshilo wokuphuma kwamandla. Ngokuhlalisa izinkinga kusenzo esinye, lezi zixhobo zincoma ukuthi izindlela zokusebenza zezilayisi zokukhanya zingavikela izinto eziphansi zokusebenza, zincoma ukuthi izindlela zokusebenza ziyasebenza ngempilo, futhi kubalulekile kakhulu ukuthi amashilo angaphumeleli kumazwe amaningi okukhanya.
Ukubhalwa kwe-DC kwe-Ground Fault kanye ne-NEC Compliance: Amcibisho we-PV ayincwadi yezinkampani zokubhalwa kwe-ground fault okuyakusinda abantu kuma-leakage currents amabi okukhuthaza ukuphila nokufa noma ukudla umlilo. Lezi zinkampani zizohlola ngokuphakeme izindlela zokugcinwa zabo ngokuphakeme futhi zizobulawa umkhondo lapho ikhona ukubhalwa kwe-ground fault ekhona kungaphezu kwe-6mA njengoba kuchazwa ku-NEC Article 690. Lezi zinkampani ziyakwazi ukubhalwa kwe-ground fault kwe-DC okubi kangaka kuma-zinkampani ezinye zokubhalwa kwe-ground fault. Ukubhalwa kwe-ground fault kuyasebenza lapho amanzi asinga kusistimu noma lapho isistimu sokugcinwa sibulawa futhi ukubhalwa kwe-ground fault kuyadala. Amcibisho we-AC wemindeni yezinkampani ezingaphansi kwezinkampani zokubhalwa kwe-ground fault ngokungafani kwe-sensitivity noma ngokungafani kwe-mechanism yokubulawa okuyakubulawa umkhondo wokubhalwa kwe-DC. Isisiseko sesensitivity noma ukubulawa kufanele kuhambisane nezinkinga zama-NEC 2020 Rules futhi ngokugcwele ku-Section 690.41(B). Amcibisho entsha we-PV ayahamba phambili kwezinkinga zokuzenzekela ngokugcina ukubhalwa ngokuphakeme kanye ne-type eyodwa yomcibisho we-DC magnetic trip. Lokhu kubonakalisa ukuthi amcibisho aqinisekile kakhulu ngokubhalwa kwe-fault kanye ne-speed kwezinkampani zokubhalwa kwe-solar ezingaphezu kwe-North America. FAQ: Yini okwenza umcibisho we-PV ukhahlukana nomcibisho wokuzenzekela? Ngaphandle kwezinkampani zokuzenzekela zokubhalwa kwe-AC ozingaphansi kokuwusa ukubhalwa kwe-DC arcs okuphambili okuyakubangela umlilo noma ukuvula, amcibisho we-PV ayawusa ukubhalwa kwe-DC arcs okuphambili futhi ngakho ayakwazi ukusebenza ngokuphelele kwezinkampani zokubhalwa kwe-photovoltaic.
Iziphi izici ezivikelayo ezifezwa ama-arc magnetic?
Ama-chutes e-magnetic arc abalulekile ekuqhekekeni nasekupholiseni ama-arc e-DC aqhubekayo nokuvimbela ukuqhuma kokushisa. Zinikeza ukuphepha nokwethembeka ezimisweni ze-PV, ngisho nasezingeni eliphezulu njengama-voltage angu-1500V.
Zisho ukuthini izinhlelo eziphakeme zamandla aphindayo?
Amandla aphakeme we-DC systems asho ukusebenza kahle okuphezulu, kodwa futhi namandla e-arc aphakeme. Lokhu kwenza kudingeke ukuba kube namajika asheshayo nokucisha okuqinile ukuze kuncishiswe umonakalo futhi kugcinwe ukuphepha.
Yini eyenziwa iziphazamisi-sifunda ze-PV ngokuphathelene nokugeleza okuphambene?
Izikhiphi zesekethe ze-PV zizwa ukubuyela emuva kwamanje futhi, zisebenzisa izinzwa kazibuthe, zivula isekethe kuphela esigabeni esithintekile, ngaleyo ndlela zivimbele umphumela we-domino nomlilo.
Lezi zindawo zokuvala zisebenza kanjani ngokuvumelana nezindinganiso ze-NEC?
Ukuze kuhlangatshezwane namazinga e-NEC, iziphazamisi zesekethe ze-PV zenzelwe iziphazamisi zesekethe zephutha lomhlaba ezilawula futhi zithole amaphutha e-DC kanye nemisinga evuzayo ukuvimbela ukushaywa ngogesi nomlilo.