Ama-inverter ayingxenye yeqembu elikhulu lama-static converter, ahlanganisa amaningi namuhla'amadivayisi akwazi ukwenza"guqula"amapharamitha kagesi kokufakwayo, njenge-voltage kanye nemvamisa, ukuze kukhiqizwe umphumela ohambisana nezidingo zomthwalo.

Ngokuvamile, ama-inverter angamadivayisi akwazi ukuguqula i-direct current ibe yi-alternating current futhi avame kakhulu ezinhlelweni zokusebenza ze-automation zezimboni kanye nama-electric drive. Ukwakheka kanye nokwakheka kwezinhlobo ezahlukene ze-inverter kuyashintsha ngokuya ngesicelo ngasinye esithile, noma ngabe umongo wenhloso yawo eyinhloko ufana (ukuguqulwa kwe-DC kuya ku-AC).

1. Ama-Inverter azimele kanye namaGridi axhunyiwe

Ama-inverter asetshenziswa ezinhlelweni ze-photovoltaic ahlukaniswe ngokomlando ngezigaba ezimbili eziyinhloko:

:Ama-inverter azimele

:Ama-inverter axhunywe kugridi

Ama-inverter azimele enzelwe izinhlelo zokusebenza lapho isitshalo se-PV singaxhunywanga kunethiwekhi enkulu yokusabalalisa amandla. I-inverter iyakwazi ukunikeza amandla kagesi emithwalweni exhunyiwe, iqinisekisa ukuzinza kwamapharamitha kagesi ayinhloko (i-voltage kanye nemvamisa). Lokhu kuzigcina ngaphakathi kwemingcele echazwe ngaphambilini, zikwazi ukumelana nezimo zokulayisha ngokweqile zesikhashana. Kulesi simo, i-inverter ihlanganiswe nesistimu yokugcina ibhethri ukuze kuqinisekiswe ukunikezwa kwamandla okuqhubekayo.

Ngakolunye uhlangothi, ama-inverter axhunywe kugridi ayakwazi ukuvumelanisa negridi kagesi axhunywe kuyo ngoba, kulokhu, i-voltage kanye nemvamisa kuyasebenza."okubekwe"ngegridi eyinhloko. Lawa ma-inverter kumele akwazi ukunqamula uma igridi eyinhloko yehluleka ukuze kugwenywe noma yikuphi ukuphakelwa okungenzeka kwegridi eyinhloko, okungaba yingozi enkulu.

Isithombe 1 - Isibonelo sesistimu ezimele kanye nesistimu exhunywe kugridi. Isithombe sivela ku-Biblus.

2. Iyini Indima Ye-Bus Capacitor

Inhloso ye-inverter ukuguqula i-voltage ye-DC waveform ibe yisignali ye-AC ukuze kufakwe amandla kumthwalo (isb. igridi yamandla) ngemvamisa ethile kanye ne-engeli encane yesigaba (φ ≈0). Isekethe elula ye-single phase unipolar Pulse-Width Modulation (PWM) iboniswe kuMfanekiso2 (uhlelo olufanayo olujwayelekile lunganwetshwa ohlelweni lwezigaba ezintathu). Kulesi simiso, uhlelo lwe-PV, olusebenza njengomthombo we-voltage we-DC olunomthombo othile wokungenisa, lubunjwa lube yisignali ye-AC ngokusebenzisa izinkinobho ezine ze-IGBT ezihambisana nama-diode akhululekile. Lezi zinkinobho zilawulwa esangweni ngesignali ye-PWM, ngokuvamile okuwumphumela we-IC oqhathanisa igagasi lokuthwala (ngokuvamile igagasi le-sine lemvamisa yokukhipha oyifunayo) kanye negagasi lokubhekisela kumvamisa ophezulu kakhulu (ngokuvamile igagasi likanxantathu ku-5-20kHz). Umphumela wama-IGBT ubunjwa ube yisignali ye-AC efanele ukusetshenziswa noma ukujova ngegridi ngokusebenzisa ama-topology ahlukahlukene ezihlungi ze-LC.

Thola Isilinganiso

Umfanekiso 2: Ukuguqulwa Kobubanzi Obushukunyiswayo (PWM) kwesigaba esisodwaukusethwa kwe-inverter. Ama-switch e-IGBT, kanye nesihlungi sokukhipha se-LC, enza isignali yokufaka ye-DC ibe isignali ye-AC esebenzisekayo. Lokhu kubangelai-voltage eyingozi egeleza kuma-terminal e-PV. Ibhasii-capacitor ilinganiswe ukuze kuncishiswe lokhu kugobhoza.

Ukusebenza kwama-IGBTs kungenisa i-voltage ye-ripple ku-terminal ye-PV array. Lokhu kugobhoza kuyingozi ekusebenzeni kohlelo lwe-PV, njengoba i-voltage ejwayelekile esetshenziswa kuma-terminals kufanele ibanjwe endaweni yamandla ephezulu (i-MPP) ye-IV curve ukuze kukhishwe amandla amaningi. I-voltage ripple kuma-terminals e-PV izophazamisa amandla akhishwe ohlelweni, okuholela ku-

amandla okukhipha aphansi ngokwesilinganiso (Isithombe 3). I-capacitor ifakwa ebhasini ukuze kusheleleke i-voltage ripple.

Umfanekiso 3: I-voltage ripple ethulwa kuma-terminal e-PV yi-PWM inverter scheme isusa i-voltage esetshenzisiwe ku-max power point (MPP) ye-PV array. Lokhu kwethula i-ripple ku-power output ye-array ukuze amandla okukhipha ajwayelekile abe ngaphansi kune-nominal MPP.

I-amplitude (ukusuka esicongweni kuya esicongweni) ye-voltage ripple inqunywa yi-switching frequency, i-PV voltage, i-bus capacitance, kanye ne-filter inductance ngokuya nge:

kuphi:

I-VPV yi-voltage ye-DC yephaneli yelanga,

I-Cbus iyi-capacitance ye-capacitor yebhasi,

I-L iyi-inductance yama-inductors esihlungi,

i-fPWM iyimvamisa yokushintsha.

Isibalo (1) sisebenza ku-capacitor efanelekile evimbela ukushaja ukuthi kudlule ku-capacitor ngesikhathi sokushaja bese ikhipha amandla atholakala ensimini kagesi ngaphandle kokumelana. Eqinisweni, ayikho i-capacitor efanelekile (Isithombe 4) kodwa yakhiwe ngezinto eziningi. Ngaphezu kwe-capacitance efanelekile, i-dielectric ayimelani ngokuphelele futhi ugesi omncane ovuzayo ugeleza usuka ku-anode uye ku-cathode ngokumelana kwe-shunt okulinganiselwe (Rsh), udlula i-capacitance ye-dielectric (C). Uma ugesi odlula ku-capacitor ugeleza, amaphini, ama-foil, kanye ne-dielectric akuhambisani kahle futhi kukhona ukumelana kochungechunge olulinganayo (ESR) ochungechungeni nge-capacitance. Okokugcina, i-capacitor igcina amandla athile ensimini yamagnetic, ngakho-ke kukhona i-inductance yochungechunge olulinganayo (ESL) ochungechungeni nge-capacitance kanye ne-ESR.

Umfanekiso 4: Isekethe elinganayo ye-capacitor ejwayelekile. I-capacitor iyiYakhiwe ngezinto eziningi ezingezona ezifanelekile, okuhlanganisa i-dielectric capacitance (C), ukumelana kwe-shunt okungenamkhawulo nge-dielectric okudlula i-capacitor, ukumelana kochungechunge (ESR), kanye ne-series inductance (ESL).

Ngisho nasengxenyeni ebonakala ilula njenge-capacitor, kunezinto eziningi ezingahluleka noma zonakale. Ngayinye yalezi zinto ingathinta ukuziphatha kwe-inverter, kokubili ezinhlangothini ze-AC kanye ne-DC. Ukuze kutholakale umphumela wokonakala kwezingxenye ze-capacitor ezingezona ezifanelekile ekuqhekekeni kwe-voltage okufakwe kuzo zonke iziphetho ze-PV, i-inverter ye-PWM unipolar H-bridge (Isithombe 2) yalingiswa kusetshenziswa i-SPICE. Ama-capacitor esihlungi kanye nama-inductor abanjwe ku-250µF kanye no-20mH, ngokulandelana. Amamodeli e-SPICE ama-IGBT athathwe emsebenzini kaPetrie et al. Isignali ye-PWM, elawula ama-switch e-IGBT, inqunywa yisekethe yokuqhathanisa kanye ne-inverting comparator yama-switch e-IGBT aphezulu naphansi, ngokulandelana. Okufakwayo kwezilawuli ze-PWM yigagasi lokuthwala i-sine elingu-9.5V, 60Hz kanye negagasi elingunxantathu elingu-10V, 10kHz.