Raws li lub hauv paus tswj ntawm lub photovoltaic system, lub inverter plays lub luag hauj lwm tseem ceeb nyob rau hauv lub lag luam thiab tso zis ntawm tag nrho cov system. Thaum lub kaw lus muaj teeb meem xws li standby, kaw, tswb, yuam kev, lub zog tsim tsis tau raws li qhov kev cia siab, cov ntaub ntawv saib xyuas cuam tshuam, thiab lwm yam, cov neeg ua haujlwm thiab cov neeg ua haujlwm tu ib txwm subconsciously pib los ntawm inverter mus nrhiav qhov laj thawj thiab kev daws teeb meem. Hauv kev sib txuas lus txhua hnub, nws pom tias txawm hais tias kev faib tawm photovoltaics tau txhim kho sai heev rau ntau xyoo, tseem muaj ntau qhov kev nkag siab tsis zoo txog inverters. Cia peb tham txog hnub no.
01 Inverter tso zis voltage?
Qhov ntsuas "AC tso zis voltage" tuaj yeem pom tau yooj yim hauv daim ntawv qhia tshwj xeeb ntawm txhua hom ntawm inverter. Nws yog ib qho tseem ceeb rau kev txheeb xyuas cov yam ntxwv qib ntawm inverter. Hauv cov ntsiab lus yooj yim, AC tso zis hluav taws xob zoo li xa mus rau tus nqi hluav taws xob tawm los ntawm AC sab ntawm lub inverter. Qhov tseeb, qhov no yog kev nkag siab yuam kev.
"AC output voltage" tsis yog qhov hluav taws xob tso tawm los ntawm inverter nws tus kheej. Lub inverter yog lub zog hluav taws xob hluav taws xob nrog cov khoom siv tam sim no. Txij li thaum nws yuav tsum tau txuas nrog rau daim phiaj hluav taws xob (Utility) kom muaj kev nyab xeeb los yog khaws cov hluav taws xob tsim hluav taws xob, nws yuav nco ntsoov xyuas qhov voltage (V) thiab zaus (F) ntawm daim phiaj nws txuas nrog lub sijhawm ua haujlwm. Txawm hais tias ob qhov tsis sib xws yog synchronized / tib yam nrog daim phiaj txiav txim siab seb lub zog hluav taws xob tawm los ntawm inverter tuaj yeem txais los ntawm daim phiaj. Txhawm rau tso tawm nws cov nqi hluav taws xob ntsuas (P=UI), lub inverter suav seb nws puas tuaj yeem tso tawm mus ntxiv thiab ntau npaum li cas rau cov zis raws li daim phiaj hluav taws xob (daim phiaj sib txuas taw tes) pom txhua lub sijhawm. Dab tsi yog qhov tso tawm rau daim phiaj ntawm no yog tam sim no (I), thiab qhov loj ntawm qhov tam sim no raug kho raws li qhov hloov pauv ntawm qhov hluav taws xob.
Ua raws li qhov xav tau los hloov 10KW ua piv txwv, yog tias daim phiaj hluav taws xob yog 400V, tus nqi tam sim no yuav tsum tau tso tawm los ntawm inverter lub sijhawm no yog: 10000÷400÷1.732≈14.5A; thaum daim phiaj hluav taws xob hloov pauv mus rau 430V ntawm lub sijhawm tom ntej, qhov yuav tsum tau tso tawm tam sim no raug kho rau 13.4A; ntawm qhov tsis sib xws, thaum daim phiaj hluav taws xob txo qis, lub inverter yuav ua kom cov zis tam sim no nce raws li. Muaj ob lub ntsiab lus kom nco ntsoov: ① Daim phiaj hluav taws xob tsis tuaj yeem nyob ntawm tus nqi tas li, nws ib txwm hloov pauv; ② Yog li, daim phiaj hluav taws xob kuaj pom los ntawm inverter yuav tsum muaj ntau yam. Yog tias qhov tseeb qhov hluav taws xob ntawm daim phiaj sib txawv tawm ntawm qhov ntau, lub inverter yuav tsum kuaj nws lub sijhawm tiag tiag thiab tshaj tawm qhov ua txhaum thiab tso tseg kom txog thaum daim phiaj hluav taws xob rov qab los. Lub hom phiaj ntawm qhov no yog los tiv thaiv kev nyab xeeb ntawm cov khoom siv hluav taws xob thiab cov neeg ua haujlwm ntawm tib txoj kab hauv substation.
Hauv qhov no, vim li cas ho tsis hloov lub npe ntawm qhov ntsuas no? Qhov laj thawj tseem ceeb yog vim li cas kev lag luam tau ua raws li tib txoj kev coj ua tau ntau xyoo - txhua tus hu nws li no; nyob rau tib lub sijhawm, txhawm rau ua kom nws sib haum nrog cov zis tam sim no, nws tau raug hu ua li no.
02 Puas yog lub inverter yuav tsum tau nruab nrog kev tiv thaiv kev tiv thaiv?
Cov lus teb yog tau kawg, tsis muaj kev poob siab. Nws tuaj yeem hais tias yog vim li cas vim li cas lub inverter tuaj yeem hu ua inverter yog vim nws muaj kev tiv thaiv kev tiv thaiv. Xav txog: yog tias lub inverter tso cai rau DC sab tawm tswv yim thiab AC sab tsis tuaj yeem tso tawm, qhov loj npaum li cas yuav mus? Lub inverter nws tus kheej tsis yog ib qho chaw cia khoom thiab tsis tuaj yeem tuav tus nqi ntau, yog li nws tseem yuav tsum tau tso tawm. Thaum cov Islanding tshwm sim, nws yog thaum lub zog ib txwm xa tawm thiab kev faib tawm ntawm daim phiaj hluav taws xob cuam tshuam rau qee yam. Thaum ib tug loj npaum li cas ntawm tus nqi nkag mus rau hauv txoj kab hluav taws xob raws li txoj kev qub, yog tias muaj cov neeg ua haujlwm kho hluav taws xob ua haujlwm nyob rau lub sijhawm no, qhov tshwm sim yuav muaj kev puas tsuaj loj. Yog li ntawd, yog tias lub tshuab hluav taws xob photovoltaic yuav tsum ua kom zoo sib xws nrog cov phiaj xwm hluav taws xob, nws yuav tsum tau nruab nrog kev tiv thaiv kev tiv thaiv kev ua haujlwm (Anti-Islanding).
Yuav ua li cas mus cuag nws? Lub ntsiab lus tseem ceeb los tiv thaiv cov nyhuv ntawm cov Islands tuaj yog qhov tseem ceeb ntawm kev kuaj xyuas cov hluav taws xob hluav taws xob hauv kab hluav taws xob. Feem ntau, ob txoj kev tshawb nrhiav "Islanding Effect", siv los yog ua haujlwm. Txawm li cas los xij ntawm txoj kev tshawb pom, thaum daim phiaj hluav taws xob tau lees paub tias tsis muaj hluav taws xob, daim phiaj-txuas inverter yuav raug txiav tawm ntawm daim phiaj thiab lub inverter yuav tsum nres tsis pub dhau lub sij hawm teb. Tus nqi teb tam sim no tau teev tseg los ntawm cov cai yog nyob rau hauv 2s.
03 Puas yog qhov siab dua ntawm DC txoj hlua hluav taws xob, lub zog hluav taws xob zoo dua?
Tsis yog tiag. Nyob rau hauv lub MPPT kev khiav hauj lwm voltage ntau ntawm lub inverter, muaj ib tug rated kev khiav hauj lwm voltage nqi. Thaum tus nqi hluav taws xob ntawm DC txoj hlua yog nyob ntawm lossis ze ntawm tus nqi ntsuas hluav taws xob ntawm lub inverter, uas yog, nyob rau hauv tag nrho cov load MPPT voltage ntau, lub inverter tuaj yeem tso tawm nws cov nqi hluav taws xob. Yog tias txoj hlua hluav taws xob siab dhau los yog qis dhau, txoj hlua hluav taws xob nyob deb ntawm qhov ntsuas hluav taws xob tus nqi / ntau qhov teeb tsa los ntawm lub inverter, thiab nws cov txiaj ntsig tau raug txo qis heev. Ua ntej, qhov muaj peev xwm ntawm outputting rated fais fab tuag yog tsis suav nrog - qhov no tsis tsim nyog; thib ob, yog tias txoj hlua hluav taws xob tsawg dhau lawm, Boost Circuit Court ntawm lub inverter yuav tsum tau nquag nquag ua haujlwm tsis tu ncua, thiab cov cua kub tsis tu ncua ua rau cov kiv cua sab hauv ua haujlwm tsis tu ncua, uas thaum kawg ua rau kev ua haujlwm tsis zoo; yog tias txoj hlua hluav taws xob siab dhau lawm, nws tsis yog tsuas yog tsis muaj kev nyab xeeb xwb, tab sis kuj txwv qhov IV tso zis nkhaus ntawm cov khoom, ua rau tam sim no me dua thiab lub zog hloov pauv loj dua. Noj 1100V inverter ua piv txwv, nws qhov ntsuas kev ua haujlwm voltage feem ntau yog 600V, thiab tag nrho-load MPPT voltage ntau ntawm 550V thiab 850V. Yog hais tias lub input voltage ntau tshaj qhov no, qhov kev ua tau zoo ntawm lub inverter tsis zoo tagnrho.