Ukukhetha Amadivayisi Okuvikela Ukwanda Kwezinhlelo ze-PV - Izinhlobo ze-SPD
Ukukhiqizwa kwamandla e-Photovoltaic (PV) kuwumthombo oyinhloko wamandla avuselelekayo futhi kuncintisana kakhulu ngokwezomnotho uma kuqhathaniswa nokukhiqizwa kwamandla kwendabuko. Izinhlelo ze-PV ezincane ezisatshalaliswayo, njengamaphaneli elanga ophahleni, ziya ngokuya zithandwa kakhulu. Izinhlelo ze-PV eziphahleni zibandakanya ukusatshalaliswa kwe-AC ne-DC ngama-voltage afinyelela ku-1500V. Uhlangothi lwe-DC, ikakhulukazi amaphaneli e-PV, angachayeka ngqo ekushayweni kombani ezindaweni ezinobungozi obukhulu, okwenza abe sengozini yokulimala kombani.
Ukuvikelwa kombani kwezakhiwo kuhlukaniswe ngokuvikelwa kwangaphandle (Uhlelo Lokuvikela Umbani, i-LPS) kanye nokuvikelwa kwangaphakathi (Izinyathelo Zokuvikela Umbani, i-SPM), ngokusekelwe engcupheni yombani. Amadivayisi Okuvikela Umbani (ama-SPD), njengengxenye yokuvikelwa kwangaphakathi, avikela ekushiseni kwamandla okushisa okudlulayo okubangelwa umbani womoya noma imisebenzi yokushintsha. Ama-SPD afakwa ngaphandle kwemishini evikelwe futhi ikakhulukazi asebenza kanje: uma kungekho ukukhuphuka kombani ohlelweni lwamandla, i-SPD ayithinti kakhulu ukusebenza okuvamile kohlelo oluvikelayo. Uma kwenzeka ukukhuphuka kombani, i-SPD inikeza ukuminyana okuphansi, iphambukisa ugesi wokuminyana ngokwawo futhi inciphise ugesi uye ezingeni eliphephile. Ngemva kokuba ukuminyana kombani sekudlulile futhi noma yimuphi ugesi osele usuphelile, i-SPD ibuyela esimweni sokuminyana okuphezulu.
1. Indawo Yokufakwa Kwamadivayisi Okuvikela Ukwanda (i-SPD)
Indawo yokufaka ama-SPD inqunywa ngokwezinga lokusongelwa kombani futhi isekelwe emcabangweni we-Lightning Protection Zones (LPZ) ku-IEC 62305. Ama-overvoltage esikhashana ancishiswa kancane kancane abe sezingeni eliphephile, okumele libe ngaphansi kwe-voltage yokumelana nemishini evikelwe. Njengoba kuboniswe kuMfanekiso, ama-SPD afakwa emingceleni yalezi zindawo, okudala umqondo wokuvikelwa kokukhuphuka kwamazinga amaningi okusetshenziswa ezinhlelweni zama-voltage aphansi. Kuzinhlelo ze-PV, ukugxila kukuvimbela ukukhuphuka kombani ukuthi kungangeni ezinhlangothini ze-AC ne-DC, ngaleyo ndlela kuvikelwe izingxenye ezibalulekile njengezi-inverters.
2. Amakilasi Okuhlola Amadivayisi Okuvikela Ukwanda (i-SPD)
Ngokusho kwe-IEC 61643-11, ama-SPD ahlukaniswe ngezigaba ezintathu zokuhlola ngokusekelwe ohlotsheni lwe-lightning current impulse aklanyelwe ukumelana nayo. Ukuhlolwa kohlobo I (okumakwe njenge-T1) kuhloswe ukulingisa imisinga yombani engaphelele engase iqhutshwe esakhiweni. Lokhu kusebenzisa i-waveform engu-10/350 µs, njengoba kuboniswe ku-Figure blow, futhi kuvame ukusetshenziswa emngceleni ophakathi kwe-LPZ0 ne-LPZ1—njengakumabhodi okusabalalisa amakhulu noma ama-transformer angenawo amandla aphansi. Ama-SPD aleli zinga ngokuvamile angohlobo lokushintshana kwamandla kagesi, anezingxenye ezifana namapayipi okukhipha igesi noma izikhala ze-spark (isb., izikhala zezimpondo noma izikhala ze-graphite).
Ukuhlolwa kohlobo lwesibili (T2) kanye nohlobo lwesithathu (T3) kusebenzisa ama-impulse esikhathi esifushane. Ama-SPD ohlobo lwesibili ngokuvamile amadivayisi anciphisa amandla kagesi asebenzisa izingxenye ezifana ne-metal oxide varistors (MOVs). Ahlolwa ngogesi wokukhipha ojwayelekile kusetshenziswa i-waveform yamanje engu-8/20 µs (bheka i-Figure blow), futhi anesibopho sokunciphisa amandla okushisa asele avela kudivayisi yokuvikela ephezulu. Ukuhlolwa kohlobo lwesithathu kusebenzisa i-combination wave generator ene-voltage engu-1.2/50 µs kanye ne-8/20 µs current impulse (bheka uMfanekiso ngezansi), okulingisa ama-surges aseduze nemishini yokusetshenziswa kokugcina.
3. Uhlobo Lokuxhuma Lwedivayisi Evikelayo Yokukhuphuka (ama-SPD)
Kunezindlela ezimbili eziyinhloko zokuvikela kuma-overvoltage esikhashana. Eyokuqala ukuvikela i-common-mode (CT1), eyenzelwe ukuvikela ekukhuphukeni phakathi kwama-conductor aphilayo kanye ne-PE (umhlaba ovikelayo). Ukushaywa kombani, isibonelo, kungangenisa ama-voltage aphezulu uma kuqhathaniswa nomhlaba ohlelweni. Ukuvikelwa kwe-common-mode kusiza ukunciphisa umthelela wokuphazamiseka okunjalo kwangaphandle, njengombani, njengoba kuboniswe ngezansi.
Okwesibili ukuvikelwa kwemodi yokuhlukanisa (CT2), okuvikela ekukhuphukeni phakathi komqhubi womugqa (L) kanye nomqhubi ongathathi hlangothi (N). Lolu hlobo lokuvikelwa lubaluleke kakhulu ekubhekaneni nokuphazamiseka kwangaphakathi, njengomsindo kagesi noma ukuphazamiseka okubangelwa uhlelo ngokwalo, njengoba kuboniswe kumdwebo ongezansi.
Ngokusebenzisa eyodwa noma zombili lezi zindlela zokuvikela, izinhlelo zikagesi zingavikelwa kangcono emithonjeni engaba khona yokuqhuma, ekugcineni kuthuthukiswe isikhathi eside kanye nokuthembeka kwemishini exhunyiwe.
Kubalulekile ukuqaphela ukuthi ukukhethwa kwezindlela zokuvikela ze-SPD kufanele kuhambisane nesistimu yokumisa phansi ekhona. Kuzinhlelo ze-TN, zombili izindlela zokuvikela ze-CT1 kanye ne-CT2 zingasetshenziswa. Kodwa-ke, ezinhlelweni ze-TT, i-CT1 ingasetshenziswa kuphela ngaphansi kwe-RCD. Ezinhlelweni ze-IT—ikakhulukazi lezo ezingenayo i-conductor engathathi hlangothi—ukuvikelwa kwe-CT2 akusebenzi. Lokhu kucatshangelwa okubalulekile ezinhlelweni zokusatshalaliswa kwe-DC ezisebenzisa ukucushwa kokumisa phansi kwe-IT. Imininingwane ingatholakala kuthebula elingezansi.
4. Amapharamitha Abalulekile Amadivayisi Okuvikela Okuphezulu (i-SPD)
Ngokusho kwe-IEC 61643-11 yamazwe ngamazwe, izici nokuhlolwa kwama-SPD axhunywe ezinhlelweni zokusatshalaliswa kwamandla aphansi kuyachazwa, njengoba kuboniswe kuMfanekiso 7.
(1) Izinga Lokuvikela I-Voltage (Phezulu)
Isici esibaluleke kakhulu ekukhetheni i-SPD yizinga layo lokuvikela i-voltage (Phezulu), elichaza ukusebenza kwe-SPD ekukhawuleleni i-voltage phakathi kwama-terminal. Leli nani kufanele libe phezulu kune-voltage ephezulu yokubopha. Lifinyelelwa lapho i-current egeleza nge-SPD ilingana ne-nominal discharge current In. Izinga lokuvikela i-voltage elikhethiwe kumele libe ngaphansi kwe-impulse ukumelana ne-voltage Uw yomthwalo. Uma kwenzeka umbani ushaya, i-voltage kuwo wonke ama-terminal e-SPD ngokuvamile igcinwa ngaphansi kwe-Uw. Kuzinhlelo ze-PV DC, umthwalo uvame ukubhekisela kumamojula e-PV nama-inverter.
(2) I-Voltage Eqhubekayo Ephezulu (Uc)
I-Uc yi-voltage ephezulu ye-DC engasetshenziswa ngokuqhubekayo kwimodi yokuvikela ye-SPD. Ikhethwa ngokusekelwe ku-voltage elinganisiwe kanye nokucushwa kwesisekelo sesistimu futhi isebenza njengomkhawulo wokusebenza we-SPD. Ohlangothini lwe-DC lwezinhlelo ze-PV, i-Uc kufanele ibe nkulu noma ilingane ne-Uoc Max ye-PV array. I-Uoc Max ibhekisela ku-voltage ephezulu kakhulu ye-open-circuit phakathi kwama-terminal abukhoma naphakathi kwe-terminal ebukhoma kanye nomhlabathi endaweni ekhethiwe ye-PV array.
(3) Ukukhishwa Kwamanje Okujwayelekile (Ngaphakathi)
Leli inani eliphakeme kakhulu lomsinga we-waveform ongu-8/20 μs ogeleza nge-SPD, osetshenziselwa ukuhlolwa kohlobo lwesibili kanye nokuhlolwa kokulungisa isimo kuhlobo lwe-1 kanye Uhlobo II. I-IEC idinga ukuthi i-SPD ikwazi ukumelana okungenani nokukhishwa okungu-19 kwamanje we-waveform ka-8/20 μs. Uma inani le-In liphakeme, isikhathi sokuphila se-SPD sihlala isikhathi eside, kodwa izindleko nazo ziyanda.
(4) Ugesi Wokushukuma (Iimp)
Ichazwa ngamapharamitha amathathu: i-current peak (Ipeak), i-charge (Q), kanye namandla athile (W/R), le current isetshenziswa ku Uhlobo I izivivinyo. I-waveform evamile ingu-10/350 μs.