Ukukhetha Izixhobo zoKhuseleko lokuKhuphuka Ukukhetha iinkqubo ze-PV - Iintlobo ze-SPD
Ukuveliswa kwamandla e-Photovoltaic (PV) ngumthombo ophambili wamandla avuselelekayo kwaye kukhuphisana kakhulu ngokwezoqoqosho xa kuthelekiswa nokuveliswa kwamandla kwendabuko. Iinkqubo ze-PV ezincinci ezisasazwe, ezifana neephaneli zelanga eziphahleni, ziya zithandwa kakhulu. Iinkqubo ze-PV eziphahleni ziquka ukusasazwa kwe-AC kunye ne-DC kunye nee-voltage ezifikelela kwi-1500V. Icala le-DC, ngakumbi iiphaneli ze-PV, zinokuchaphazeleka ngokuthe ngqo kumbane kwiindawo ezinobungozi obukhulu, nto leyo ebangela ukuba zibe sesichengeni sokulimala kombane.
Ukhuseleko lombane kwizakhiwo lwahlulwe lwaba lukhuselo lwangaphandle (iNkqubo yoKhuselo loMbane, i-LPS) kunye nokhuselo lwangaphakathi (iiMeasures zoKhuselo loMbane, i-SPM), ngokusekelwe kumngcipheko wombane. Izixhobo zoKhuselo loMbane (ii-SPD), njengenxalenye yokhuseleko lwangaphakathi, zikhusela kwi-overvoltages ezidlulayo ezibangelwa yi-atmospheric lightning okanye imisebenzi yokutshintsha. Ii-SPD zifakelwa ngaphandle kwezixhobo ezikhuselweyo kwaye ikakhulu zisebenza ngolu hlobo lulandelayo: xa kungekho kunyuka kwenkqubo yamandla, i-SPD ayichaphazeli kakhulu ukusebenza okuqhelekileyo kwenkqubo eyikhuselayo. Xa kuvela ukunyuka, i-SPD inikezela nge-impedance ephantsi, ijika i-surge current ngokwayo kwaye inciphise i-voltage ukuya kwinqanaba elikhuselekileyo. Emva kokuba ukunyuka kudlulile kwaye nayiphi na i-residual current iphelile, i-SPD ibuyela kwimeko ye-impedance ephezulu.
1. Indawo yoFakelo lweZixhobo zoKhuselo lweSurge (SPD)
Indawo yokufakelwa kwee-SPD imiselwa ngokwezinga lomngcipheko wombane kwaye isekelwe kwingcamango yeLightning Protection Zones (LPZ) kwi-IEC 62305. Ii-overvoltages zesikhashana ziyancitshiswa ngokuthe ngcembe ziye kwinqanaba elikhuselekileyo, ekufuneka libe ngaphantsi kwe-voltage yokumelana nezixhobo ezikhuselweyo. Njengoko kubonisiwe kuMfanekiso, ii-SPD zifakelwe kwimida yale mimandla, nto leyo ebangela ingcamango yokhuseleko lwe-surge olunamanqanaba amaninzi olusetyenziswa kwiinkqubo ze-voltage ephantsi. Kwiinkqubo ze-PV, ingqwalasela ikukuthintela ukugqabhuka kombane ukuba kungangeni kumacala e-AC kunye ne-DC, ngaloo ndlela kukhuselwa izinto ezibalulekileyo ezifana nee-inverters.
2. Iiklasi zovavanyo lwezixhobo zokukhusela ukuqhuma (i-SPD)
Ngokutsho kwe-IEC 61643-11, ii-SPD zahlulwe zibe ziindidi ezintathu zovavanyo ngokusekelwe kuhlobo lwe-lightning current impulse ezenzelwe ukumelana nayo. Uvavanyo lwe-Type I (oluphawulwe njenge-T1) lwenzelwe ukulinganisa imisinga yombane engaphelelanga enokuthi iqhutywe kwisakhiwo. Ezi zisebenzisa i-waveform ye-10/350 µs, njengoko kubonisiwe kuMfanekiso, kwaye zihlala zisetyenziswa kumda ophakathi kwe-LPZ0 kunye ne-LPZ1—njengakwiibhodi eziphambili zokusasaza okanye kwi-transformer ezisebenzisa i-voltage ephantsi. Ii-SPD zale nqanaba zihlala ziluhlobo lokutshintsha i-voltage, kunye nezinto ezifana neetyhubhu zokukhupha igesi okanye izithuba ze-spark (umz., izithuba zeempondo okanye izithuba ze-graphite).
Uvavanyo lwe-Type II (T2) kunye nohlobo lwe-III (T3) lusebenzisa ii-impulses zexesha elifutshane. Ii-SPD ze-Type II zihlala zizixhobo ezithintela i-voltage ezisebenzisa izinto ezifana ne-metal oxide varistors (MOVs). Zivavanywa nge-nominal discharge current kusetyenziswa i-8/20 µs current waveform (jonga uMfanekiso wokuqhuma), kwaye zinoxanduva lokunciphisa ngakumbi i-residual surge voltage evela kwisixhobo sokukhusela esingaphezulu. Uvavanyo lwe-Type III lusebenzisa i-combination wave generator ene-1.2/50 µs voltage kunye ne-8/20 µs current impulse (jonga uMfanekiso ongezantsi), zilinganisa ii-surges ezikufutshane nezixhobo zokusetyenziswa kokugqibela.
3. Uhlobo loQhagamshelo lweSixhobo soKhuselo lokuKhukula (ii-SPD)
Kukho iindlela ezimbini eziphambili zokukhusela kwi-overvoltages ezidlulayo. Eyokuqala yi-common-mode protection (CT1), eyenzelwe ukukhusela kwi-surges phakathi kwee-live conductors kunye ne-PE (protective earth). Ukutshayiswa kombane, umzekelo, kunokungenisa i-voltages ephezulu xa kuthelekiswa nomhlaba kwinkqubo. Ukhuseleko lwe-common-mode lunceda ukunciphisa impembelelo yokuphazamiseka kwangaphandle, njengombane, njengoko kuboniswe ngezantsi.
Okwesibini kukukhusela imo ye-differential-mode (CT2), ekhusela ukugqobhoza phakathi komqhubi womgca (L) kunye nomqhubi ongathathi cala (N). Olu hlobo lokhuseleko lubaluleke kakhulu ekusombululeni ukuphazamiseka kwangaphakathi, okufana nengxolo yombane okanye ukuphazamiseka okubangelwa yinkqubo ngokwayo, njengoko kubonisiwe kumzobo ongezantsi.
Ngokusebenzisa enye okanye zombini ezi ndlela zokukhusela, iinkqubo zombane zinokukhuseleka ngcono kwimithombo enokubakho yokutsalwa kwamandla, ekugqibeleni ziphucule ixesha elide kunye nokuthembeka kwezixhobo ezixhunyiweyo.
Kubalulekile ukuqaphela ukuba ukukhethwa kweendlela zokukhusela ze-SPD kufuneka kuhambelane nenkqubo yokumisa umhlaba ekhoyo. Kwiinkqubo ze-TN, zombini iindlela zokukhusela ze-CT1 kunye ne-CT2 zingasetyenziswa. Nangona kunjalo, kwiinkqubo ze-TT, i-CT1 inokusetyenziswa kuphela ngezantsi kwe-RCD. Kwiinkqubo ze-IT—ingakumbi ezo zingenawo umqhubi ongathathi cala—ukhuseleko lwe-CT2 alusebenzi. Olu luqwalaselo olubalulekileyo kwiinkqubo zokusasazwa kwe-DC ezisebenzisa ulungelelwaniso lokumisa umhlaba lwe-IT. Iinkcukacha zingafumaneka kwitheyibhile engasezantsi.
4. Iiparameter eziphambili zeZixhobo zoKhuselo lweSurge (i-SPD)
Ngokwemigangatho yamazwe ngamazwe ye-IEC 61643-11, iimpawu kunye novavanyo lwee-SPDs eziqhagamshelwe kwiinkqubo zokusasazwa kwamandla aphantsi zichaziwe, njengoko kuboniswe kuMfanekiso 7.
(1) Inqanaba loKhuseleko lweVolthi (Phezulu)
Eyona nto ibalulekileyo ekukhetheni i-SPD linqanaba layo lokukhusela i-voltage (Up), elichaza ukusebenza kwe-SPD ekunciphiseni i-voltage phakathi kwee-terminals. Eli xabiso kufuneka libe phezulu kune-voltage ephezulu yokucinezela. Lifikelelwa xa i-current ehamba nge-SPD ilingana ne-nominal discharge current In. Inqanaba lokukhusela i-voltage ekhethiweyo kufuneka libe ngaphantsi kune-impulse standing voltage Uw yomthwalo. Kwimeko yokubetha kombane, i-voltage kuzo zonke ii-terminals ze-SPD igcinwa ingaphantsi kwe-Up. Kwiinkqubo ze-PV DC, umthwalo udla ngokubhekisa kwiimodyuli ze-PV kunye nee-inverters.
(2) Ubuninzi beVolthi yokuSebenza eQhubekayo (Uc)
I-Uc yeyona voltage iphezulu ye-DC enokusetyenziswa rhoqo kwimo yokukhusela i-SPD. Ikhethwa ngokusekelwe kwi-voltage elinganisiweyo kunye noqwalaselo lwesiseko senkqubo kwaye isebenza njengomda wokuvula we-SPD. Kwicala le-DC leenkqubo ze-PV, i-Uc kufuneka ibe nkulu okanye ilingane ne-Uoc Max ye-PV array. I-Uoc Max ibhekisa kwi-voltage ephezulu ye-open-circuit phakathi kwee-terminals eziphilayo kunye naphakathi kwe-terminal ephilayo kunye nomhlaba kwindawo ekhethiweyo ye-PV array.
(3) Umbane oKhutshwayo oNgenani (ngaphakathi)
Eli lixabiso eliphezulu lomsinga we-8/20 μs waveform ohamba nge-SPD, osetyenziselwa uvavanyo lwe-Type II kunye novavanyo lokulungisa kwangaphambili kwi-Type I kunye Uhlobo III-IEC ifuna ukuba i-SPD ikwazi ukumelana nokukhutshwa kwe-8/20 μs waveform current ubuncinane izihlandlo ezili-19. Okukhona ixabiso le-In liphezulu, kokukhona ixesha le-SPD lihlala ixesha elide, kodwa ixabiso nalo liyakhula.
(4) Umsinga weMpembelelo (Iimp)
Ichazwa ziiparameter ezintathu: i-current peak (Ipeak), itshaja (Q), kunye namandla athile (W/R), le current isetyenziswa kwi Uhlobo I iimvavanyo. Uhlobo oluqhelekileyo lwamaza yi-10/350 μs.