Morero oa inverter ke ho fetola voltage ea waveform ea DC hore e be lets'oao la AC e le ho kenya matla ho mojaro (mohlala, grid ea matla) ka lebelo le fanoeng le ka angle e nyane ea mohato.φ ≈0).Potoloho e nolofalitsoeng bakeng sa karolo e le 'ngoe ea unipolar Pulse-Width Modulation (PWM) e bontšoa setšoantšong.2 (sekema se tšoanang se akaretsang se ka fetisetsoa tsamaisong ea mekhahlelo e meraro).Lenaneong lena, sistimi ea PV, e sebetsang e le mohloli oa motlakase oa DC o nang le mohloli o mong oa inductance, e bōptjoa hore e be lets'oao la AC ka li-switch tse 'ne tsa IGBT tse tsamaisanang le li-diode tsa freewheeling.Li-switch tsena li laoloa hekeng ka lets'oao la PWM, leo hangata e leng tlhahiso ea IC e bapisang leqhubu la sephethephethe (hangata ke sine wave ea frequency e lakatsehang) le leqhubu la litšupiso ka lebelo le phahameng haholo (hangata leqhubu la kgutlotharo. 5-20kHz).Sehlahisoa sa li-IGBT se bōptjoa hore e be lets'oao la AC le loketseng ho sebelisoa kapa ente ea marang-rang ka ts'ebeliso ea li-topology tse fapaneng tsa li-filters tsa LC.
Li-inverters ke tsa sehlopha se seholo sa li-converter tse tsitsitseng, tse kenyelletsang tse ngata tsa kajeno's lisebelisoa khona ho“fetola”li-parameter tsa motlakase tse kenang, tse kang voltage le frequency, e le ho hlahisa tlhahiso e lumellanang le litlhoko tsa mojaro.
Ka kakaretso, li-inverters ke lisebelisoa tse khonang ho fetola hona joale ka kotloloho hore e be tse feto-fetohang 'me li atile haholo lits'ebetsong tsa liindasteri le li-drive tsa motlakase.Mehaho le moralo oa mefuta e fapaneng ea li-inverter li fetoha ho latela ts'ebeliso e 'ngoe le e' ngoe e ikhethileng, le haeba mantlha a sepheo sa bona se seholo se ts'oana (phetoho ea DC ho AC).
1.Li-Inverters tse ikemetseng le tsa Grid-Connected
Li-inverters tse sebelisoang lits'ebetsong tsa photovoltaic li arotsoe ka mekhahlelo e 'meli ea mantlha:
:Li-inverters tse ikemetseng
:Li-inverters tse amanang le grid
Li-inverters tse ikemetseng ke tsa lits'ebetso moo semela sa PV se sa hokahaneng le marang-rang a mantlha a kabo ea matla.Inverter e khona ho fana ka matla a motlakase mejaro e hokahantsoeng, ho netefatsa botsitso ba litekanyetso tse kholo tsa motlakase (voltage le frequency).Sena se ba boloka ka har'a meeli e boletsoeng esale pele, ba khona ho mamella maemo a nakoana a boima.Boemong bona, inverter e kopantsoe le sistimi ea polokelo ea betri ho netefatsa phepelo e tsitsitseng ea matla.
Ka lehlakoreng le leng, li-inverters tse hokahaneng le grid li khona ho hokahana le marang-rang a motlakase ao li hokahaneng ho ona hobane, ntlheng ena, motlakase le maqhubu li teng.“behelletsoe”ka keriti e kholo.Li-inverters tsena li tlameha ho khona ho hakolla haeba grid e kholo e hloleha ho qoba phepelo efe kapa efe e ka bang teng ea grid e kholo, e ka emelang kotsi e kholo.
- Setšoantšo sa 1 - Mohlala oa Sistimi e ikemetseng le sistimi e hokahaneng le Grid.Setšoantšo se amoheloa ke Biblus.
2.Seabo sa Bus Capacitor ke Efe
Setšoantšo sa 2: Pulsed Width Modulation (PWM) mohato o le mongsesebelisoa sa inverter.Li-switch tsa IGBT, hammoho le filthara ea LC, li theha lets'oao la ho kenya la DC hore e be lets'oao le sebelisoang la AC.Sena se susumetsa aho phatloha ha motlakase ho pholletsa le li-terminals tsa PV.Besecapacitor e boholo bo lekaneng ho fokotsa ripple ena.
Ts'ebetso ea li-IGBT e hlahisa motlakase oa ripple ho terminal ea PV array.Ripple ena e senya ts'ebetso ea sistimi ea PV, kaha motlakase o sebelisoang ho li-terminal o lokela ho ts'oaroa sebakeng se phahameng sa motlakase (MPP) sa 4 curve e le ho ntša matla a mangata.Ho phatloha ha voltage ho li-terminals tsa PV ho tla fokotsa matla a ntšitsoeng tsamaisong, e leng se etsang hore ho be le
karolelano e tlase ea matla a matla (Setšoantšo sa 3).Ho eketsoa capacitor ka beseng e le ho theola molumo oa motlakase.
Setšoantšo sa 3: Ripple ea motlakase e hlahisitsoeng li-terminals tsa PV ke "inverter scheme" ea PWM e tlosa motlakase o sebelisoang sebakeng se seholo sa matla (MPP) sa sehlopha sa PV.Sena se hlahisa ripple ho tlhahiso ea matla ea sehlopha e le hore karolelano ea matla a tsoang a be tlase ho feta MPP ea lebitso.
The amplitude (tlhoro ho fihla tlhorong) ea ripple ea motlakase e khethoa ke maqhubu a switching, PV voltage, capacitance bese, le filter inductance ho latela:
moo:
VPV ke motlakase oa letsatsi la DC,
Cbus ke bokhoni ba capacitor ea libese,
L ke inductance ea li-inductors tsa filthara,
fPWM ke maqhubu a ho fetoha.
Equation (1) e sebetsa ho capacitor e loketseng e thibelang tefiso ho phalla ka capacitor nakong ea ho tjhaja ebe e ntša matla a teng sebakeng sa motlakase ntle le khanyetso.Ha e le hantle, ha ho na capacitor e loketseng (Setšoantšo sa 4) empa e entsoe ka likarolo tse ngata.Ntle le bokhoni bo botle, dielectric ha e khone ho hanyetsa ka ho feletseng 'me hona joale ho phalla ho honyenyane ho phalla ho tloha anode ho ea ho cathode hammoho le finite shunt resistance (Rsh), ho feta matla a dielectric capacitance (C).Ha ho ntse ho phalla ka har'a capacitor, lithakhisa, li-foil le dielectric ha li sebetse hantle 'me ho na le letoto le lekanang la ho hanyetsa (ESR) ka letoto le nang le bokhoni.Qetellong, capacitor e boloka matla a mang a matla a khoheli, kahoo ho na le equivalent series inductance (ESL) letoto le nang le capacitance le ESR.
Setšoantšo sa 4: Potoloho e lekanang ea capacitor ea generic.A capacitor kee entsoe ka lintho tse ngata tse sa lokelang, ho kenyelletsa le dielectric capacitance (C), e sa feleng ea shunt resistance ka dielectric e fetang capacitor, series resistance (ESR), le series inductance (ESL).
Esita le karolong e bonahalang e le bonolo joaloka capacitor, ho na le likarolo tse ngata tse ka hlōlehang kapa tsa theola.E 'ngoe le e' ngoe ea likarolo tsena e ka ama boitšoaro ba inverter, mahlakoreng a AC le DC.E le ho fumana hore na phello ea ho senyeha ha likarolo tsa capacitor tse sa lokelang ho na le ripple ea motlakase e hlahisitsoeng ho pholletsa le li-terminals tsa PV, mochine oa PWM oa H-bridge inverter (Setšoantšo sa 2) o ile oa etsisoa ho sebelisoa SPICE.Li-filter capacitor le li-inductors li tšoaroa ho 250µF le 20mH, ka ho latellana.Mefuta ea SPICE bakeng sa li-IGBT e tsoa mosebetsing oa Petrie et al.Letšoao la PWM, le laolang li-switch tsa IGBT, le khethoa ke comparator le inverting comparator circuit bakeng sa li-switches tsa IGBT tse phahameng le tse tlaase, ka ho latellana.Kenyelletso bakeng sa taolo ea PWM ke 9.5V, 60Hz sine carrier wave le 10V, 10kHz khutlotharo leqhubu.
- Tharollo ea CRE
CRE ke k'hamphani ea theknoloji e phahameng e ikhethileng tlhahisong ea li-capacitor tsa lifilimi, e shebaneng le ts'ebeliso ea matla a motlakase.
CRE e fana ka tharollo e tsoetseng pele ea letoto la li-capacitor tsa filimi bakeng sa inverter ea PV e kenyelletsang DC-link, AC-filter le snubber.
Nako ea poso: Dec-01-2023