Ama-inverter ayingxenye yeqembu elikhulu labaguquli abamile, abahlanganisa abaningi banamuhla's amadivayisi akwazi“guqula”amapharamitha kagesi okokufaka, njenge-voltage ne-frequency, ukuze kukhiqizwe okukhiphayo okuhambisana nezidingo zomthwalo.

Ngokuvamile, ama-inverter angamadivayisi akwazi ukuguqula i-current eqondile abe i-alternating current futhi avame kakhulu ezinhlelweni zokusebenza ezishintshayo zezimboni namadrayivu kagesi.Izakhiwo kanye nomklamo wezinhlobo ezahlukene ze-inverter ziyashintsha ngokuya ngohlelo ngalunye oluthile, noma ngabe umnyombo wenjongo yawo eyinhloko ufana (ukuguqulwa kwe-DC kuya ku-AC).

1.Iziguquli ezizimele kanye nezixhunywe kwiGridi

Ama-inverters asetshenziswa ezinhlelweni ze-photovoltaic ahlukaniswe ngokomlando abe yizigaba ezimbili eziyinhloko:

:Ama-inverters azimele

:Ama-inverters axhunywe kwigridi

Ama-inverter azimele awezinhlelo zokusebenza lapho isitshalo se-PV singaxhumekile kunethiwekhi enkulu yokusabalalisa amandla.I-inverter iyakwazi ukunikeza amandla kagesi emithwalweni exhunyiwe, iqinisekisa ukuzinza kwemingcele eyinhloko kagesi (i-voltage kanye nemvamisa).Lokhu kuzigcina zingaphakathi kwemikhawulo echazwe ngaphambilini, zikwazi ukumelana nezimo zesikhashana zokugcwala ngokweqile.Kulesi simo, i-inverter ihlanganiswe nesistimu yokugcina ibhethri ukuze kuqinisekiswe ukunikezwa kwamandla okungaguquki.

Ngakolunye uhlangothi, ama-inverter axhunywe kwigridi, ayakwazi ukuvumelanisa negridi kagesi axhunywe kuyo ngoba, kulokhu, i-voltage kanye nemvamisa kukhona.“ebekiwe”ngegridi eyinhloko.Lawa ma-inverters kufanele akwazi ukunqamula uma igridi eyinhloko ihluleka ukuze kugwenywe noma yikuphi ukunikezwa okungenzeka okuhlehliswayo kwegridi eyinhloko, okungamelela ingozi enkulu.

Umfanekiso 1 - Isibonelo sohlelo oluzimele kanye nohlelo oluxhunywe kwiGridi.Isithombe sihlonishwa yi-Biblus.

2.Iyini indima ye-Bus Capacitor

Inhloso ye-inverter ukuguqula i-DC waveform voltage ibe isignali ye-AC ukuze ifake amandla emthwalweni (isb. igridi yamandla) ngefrikhwensi enikeziwe kanye ne-engeli yesigaba esincane (φ ≈0).Isekhethi eyenziwe lula yesigaba esisodwa se-unipolar Pulse-Width Modulation (PWM) iboniswa kuMfanekiso.2 (isikimu esijwayelekile esifanayo singanwetshwa ohlelweni lwezigaba ezintathu).Kulolu hlelo, isistimu ye-PV, esebenza njengomthombo wamandla kagesi we-DC enomthombo othile wokugudluza, ilolongwa ibe isignali ye-AC ngokusebenzisa amaswishi amane e-IGBT ahambisana nama-freewheeling diode.Lezi zinguquko zilawulwa esangweni ngesignali ye-PWM, ngokuvamile ewumphumela we-IC eqhathanisa igagasi lenkampani yenethiwekhi (imvamisa igagasi le-sine lemvamisa yokuphumayo oyifunayo) kanye negagasi eliyireferensi elivamise ukuphakama kakhulu (imvamisa igagasi elingunxantathu). ngo-5-20kHz).Okuphumayo kwama-IGBT kubunjwa kube isignali ye-AC elungele ukusetshenziswa noma umjovo wegridi ngokusebenzisa ama-topology ahlukahlukene wezihlungi ze-LC.

Thola i-Quote

Umfanekiso 2: I-Pulsed Width Modulation (PWM) isigaba esisodwaukusethwa kwe-inverter.Amaswishi e-IGBT, kanye nesihlungi sokuphumayo se-LC, alolonge isiginali yokufaka ye-DC ibe isignali ye-AC esebenzisekayo.Lokhu kudala ai-deleterious voltage ripple kuwo wonke amatheminali e-PV.Ibhasii-capacitor ilinganiselwe ukuze kwehliswe le ripple.

Ukusebenza kwama-IGBT kwethula i-ripple voltage kutheminali yamalungu afanayo e-PV.Lokhu ripple kuyasusa ekusebenzeni kwesistimu ye-PV, njengoba i-voltage yegama esetshenziswa kumatheminali kufanele ibanjwe endaweni yamandla enkulu (MPP) yejika le-IV ukuze kukhishwe amandla amaningi.I-voltage ripple kumatheminali e-PV izonyakazisa amandla akhishwe ohlelweni, okuholela ekutheni

okukhipha amandla okumaphakathi okumaphakathi (Umfanekiso 3).I-capacitor yengezwa ebhasini ukuze kusheleleke i-voltage ripple.

Umfanekiso 3: I-voltage ripple eyethulwe kumatheminali e-PV ngohlelo lokuguqulela i-PWM lususa i-voltage esetshenzisiwe isuke endaweni enkulu yamandla (MPP) yohlelo lwe-PV.Lokhu kwethula i-ripple ekuphumeni kwamandla kwelungu ukuze amandla okukhiphayo amaphakathi abe ngaphansi kune-MPP yokulinganisa.

I-amplitude (ukuphakama ukuya phezulu) ye-voltage ripple inqunywa imvamisa yokushintsha, i-PV voltage, umthamo webhasi, kanye ne-inductance yesihlungi ngokusho:

kuphi:

I-VPV iyiphaneli yelanga ye-DC voltage,

I-Cbus amandla e-capacitor yebhasi,

U-L ukufakwa kwama-inductors okuhlunga,

I-fPWM imvamisa yokushintsha.

Isibalo (1) sisebenza ku-capacitor ekahle evimbela ukushaja ekugelezeni ku-capacitor ngesikhathi sokushaja bese ikhipha amandla atholakala endaweni kagesi ngaphandle kokumelana.Eqinisweni, ayikho i-capacitor efanelekile (Umfanekiso 4) kodwa yakhiwe izakhi eziningi.Ngokungeziwe kumandla afanelekile, i-dielectric ayinqandeki ngokuphelele futhi ukuvuza okuncane kwamanje kugeleza ukusuka ku-anode kuya ku-cathode ngokuhambisana ne-finite shunt resistance (Rsh), kudlule amandla e-dielectric (C).Uma kugeleza okwamanje nge-capacitor, izikhonkwane, ama-foil, ne-dielectric akuhambisani kahle futhi kukhona ukumelana nochungechunge olulinganayo (ESR) ochungechungeni olunamandla.Okokugcina, i-capacitor igcina amandla athile endaweni kazibuthe, ngakho-ke kukhona i-series inductance efanayo (ESL) ochungechungeni olunamandla kanye ne-ESR.

Umfanekiso 4: Isekethe elinganayo ye-generic capacitor.I-capacitoryakhiwe ngezinto eziningi ezingafanelekile, okuhlanganisa i-dielectric capacitance (C), ukumelana kwe-shunt okungapheli ngokusebenzisa i-dielectric edlula i-capacitor, ukumelana nochungechunge (ESR), kanye ne-series inductance (ESL).

Ngisho nasengxenyeni ebonakala ilula njenge-capacitor, kukhona izakhi eziningi ezingahluleka noma zilulaze.Ngayinye yalezi zakhi ingathinta ukuziphatha kwe-inverter, kokubili ezinhlangothini ze-AC ne-DC.Ukuze unqume ukucekelwa phansi komthelela wezingxenye ze-capacitor ezingafanelekile ezikhona ku-voltage ripple eyethulwe kuwo wonke amatheminali e-PV, i-PWM unipolar H-bridge inverter (Umfanekiso 2) yalingiswa kusetshenziswa i-SPICE.Ama-capacitor okuhlunga nama-inductors abanjwe ku-250µF no-20mH, ngokulandelanayo.Amamodeli we-SPICE wama-IGBT athathwe emsebenzini kaPetrie et al.Isiginali ye-PWM, elawula ukushintshwa kwe-IGBT, inqunywa isiqhathanisi nesiguquli sesekethe yesiqhathanisi samaswishi e-IGBT aphezulu naphansi, ngokulandelana.Okokufaka kwezilawuli ze-PWM igagasi elingunxantathu elingu-9.5V, 60Hz ne-10V, 10kHz elingunxantathu.

Isixazululo se-CRE

I-CRE yibhizinisi lobuchwepheshe obuphezulu elisebenza ngokukhethekile ekukhiqizeni ama-capacitor amafilimu, eligxile ekusebenziseni amandla kagesi.

I-CRE inikezela ngesixazululo esivuthiwe sochungechunge lwefilimu ye-capacitor ye-PV inverter ehlanganisa i-DC-link, isihlungi se-AC kanye ne-snubber.