Ma inverters ali m'gulu lalikulu la otembenuza static, omwe akuphatikizapo ambiri masiku ano's zipangizo angathe“tembenuzani”magawo amagetsi pakulowetsa, monga voteji ndi ma frequency, kuti apange zotulutsa zomwe zimagwirizana ndi zofunikira za katunduyo.

Nthawi zambiri, ma inverters ndi zida zomwe zimatha kusinthira zomwe zikuchitika kuti zikhale zosinthira ndipo ndizofala kwambiri pamakina opangira makina ndi ma drive amagetsi.Zomangamanga ndi mapangidwe amitundu yosiyanasiyana ya inverter amasintha malinga ndi ntchito iliyonse, ngakhale pachimake cha cholinga chawo chachikulu ndi chofanana (kutembenuka kwa DC kupita ku AC).

1.Standalone ndi Gridi-olumikizidwa Inverters

Ma inverters omwe amagwiritsidwa ntchito popanga ma photovoltaic amagawidwa m'magulu awiri:

:Ma inverters odziyimira pawokha

:Ma inverters olumikizidwa ndi grid

Ma standalone inverters ndi a mapulogalamu omwe PV chomera sichimalumikizidwa ndi netiweki yayikulu yogawa mphamvu.Inverter imatha kupereka mphamvu zamagetsi kuzinthu zolumikizidwa, kuonetsetsa kukhazikika kwa magawo akulu amagetsi (voltage ndi pafupipafupi).Izi zimawasunga m'malire omwe adadziwika kale, kuti athe kupirira pakanthawi kochepa kwambiri.Munthawi imeneyi, inverter imaphatikizidwa ndi makina osungira mabatire kuti zitsimikizire kuti magetsi azikhala okhazikika.

Komano, ma inverter olumikizidwa ndi ma gridi amatha kulunzanitsa ndi gridi yamagetsi komwe amalumikizidwa chifukwa, pakadali pano, magetsi ndi ma frequency ndi“kukakamiza”pa gridi yayikulu.Ma inverterswa ayenera kutha kulumikizidwa ngati gridi yayikulu ikulephera kuti apewe kubweza kulikonse kwa gridi yayikulu, zomwe zitha kuyimira ngozi yayikulu.

Chithunzi 1 - Chitsanzo cha Standalone system ndi Grid-connected system.Chithunzi mwachilolezo cha Biblus.

2.Kodi Udindo wa Bus Capacitor ndi chiyani

Cholinga cha inverter ndikusintha magetsi a DC waveform kukhala siginecha ya AC kuti alowetse mphamvu mu katundu (mwachitsanzo, gridi yamagetsi) pafupipafupi komanso pang'ono.φ ≈0).Dera losavuta la gawo limodzi la unipolar Pulse-Width Modulation (PWM) likuwonetsedwa pachithunzi.2 (chiwembu chomwecho chikhoza kuwonjezeredwa ku dongosolo la magawo atatu).Pachitsanzo ichi, makina a PV, omwe amagwira ntchito ngati gwero lamagetsi la DC okhala ndi magwero ena, amapangidwa kukhala chizindikiro cha AC kudzera pa masiwichi anayi a IGBT omwe amafanana ndi ma diode a freewheeling.Zosinthazi zimayendetsedwa pachipata kudzera pa chizindikiro cha PWM, chomwe nthawi zambiri chimakhala chotulutsa IC chomwe chimafanizira mafunde onyamula (nthawi zambiri mafunde amtundu womwe amafunidwa) komanso mafunde amawu pama frequency apamwamba kwambiri (nthawi zambiri mafunde a triangle). pa 5-20 kHz).Kutulutsa kwa ma IGBT kumapangidwa kukhala siginecha ya AC yoyenera kugwiritsidwa ntchito kapena jekeseni wa gridi pogwiritsa ntchito mitundu yosiyanasiyana ya zosefera za LC.

Pezani Mawu

Chithunzi 2: Pulsed Width Modulation (PWM) gawo limodzikupanga inverter.Kusintha kwa IGBT, limodzi ndi fyuluta yotulutsa LC, kumapanga chizindikiro cha DC kukhala chizindikiro cha AC.Izi zimabweretsa aKuphulika kwamphamvu kwamagetsi kumadutsa ma terminals a PV.Basicapacitor ndi kukula kwake kuti muchepetse ripple iyi.

Kugwira ntchito kwa ma IGBT kumabweretsa voteji yothamanga pa terminal ya PV array.Ripple iyi ndiyoyipa pakugwira ntchito kwa PV system, chifukwa voteji yomwe imayikidwa pamaterminal iyenera kuchitikira pa max power point (MPP) ya IV curve kuti atenge mphamvu zambiri.Kuthamanga kwamagetsi pazigawo za PV kudzasokoneza mphamvu yochotsedwa mu dongosolo, zomwe zimapangitsa

kutulutsa mphamvu kwapakati (Chithunzi 3).Capacitor imawonjezedwa m'basi kuti muwongolere mphamvu yamagetsi.

Chithunzi 3: Voltage ripple yomwe idalowetsedwa pamaterminal a PV ndi pulogalamu ya inverter ya PWM imasuntha voteji yomwe imagwiritsidwa ntchito kuchoka pamphamvu yamphamvu (MPP) ya gulu la PV.Izi zimabweretsa kutulutsa mphamvu kwa gululo kuti mphamvu zotulutsa zizikhala zotsika kuposa zomwe zimatchedwa MPP.

Matalikidwe (pamwamba mpaka pachimake) cha voteji ripple amatsimikiziridwa ndi kusintha pafupipafupi, voteji ya PV, capacitance ya basi, ndi inductance fyuluta molingana ndi:

kumene:

VPV ndiye magetsi a solar DC,

Cbus ndi mphamvu ya basi capacitor,

L ndiye inductance ya zosefera inductors,

fPWM ndikusintha pafupipafupi.

Equation (1) imagwira ntchito ku capacitor yabwino yomwe imalepheretsa kuti mtengo usadutse kudzera mu capacitor panthawi yolipiritsa ndiyeno umatulutsa mphamvu yomwe ili mugawo lamagetsi popanda kukana.Zoona zake, palibe capacitor yabwino (Chithunzi 4) koma imapangidwa ndi zinthu zambiri.Kuphatikiza pa kuthekera koyenera, dielectric siilimbana bwino ndipo kutsika kwakung'ono kumayenda kuchokera ku anode kupita ku cathode motsatana ndi finite shunt resistance (Rsh), kudutsa mphamvu ya dielectric (C).Pamene pakali pano kudzera mu capacitor ikuyenda, mapini, zojambulazo, ndi dielectric sizikuyenda bwino ndipo pali zofanana zotsutsana (ESR) zotsatizana ndi capacitance.Pomaliza, capacitor imasunga mphamvu mu mphamvu ya maginito, kotero pali yofanana mndandanda inductance (ESL) mndandanda ndi capacitance ndi ESR.

Chithunzi 4: Chigawo chofanana cha generic capacitor.Capacitor ndiwopangidwa ndi zinthu zambiri zomwe sizili bwino, kuphatikiza dielectric capacitance (C), kukana kopanda malire kwa shunt kudzera mu dielectric yomwe imadutsa capacitor, series resistance (ESR), ndi series inductance (ESL).

Ngakhale mu gawo lowoneka ngati losavuta ngati capacitor, pali zinthu zingapo zomwe zimatha kulephera kapena kutsitsa.Chilichonse mwazinthu izi chimatha kukhudza machitidwe a inverter, mbali zonse za AC ndi DC.Pofuna kudziwa momwe kuwonongeka kwa zigawo zomwe sizili bwino za capacitor zili ndi mphamvu yamagetsi yomwe imayambitsidwa kudutsa ma terminals a PV, inverter ya PWM unipolar H-bridge inverter (Chithunzi 2) inayesedwa pogwiritsa ntchito SPICE.Ma capacitor ndi ma inductors amakhala pa 250µF ndi 20mH, motsatana.Zitsanzo za SPICE za IGBT zimachokera ku ntchito ya Petrie et al.Chizindikiro cha PWM, chomwe chimayang'anira kusintha kwa IGBT, chimatsimikiziridwa ndi ofananitsa ndi inverting comparator circuit for high and low-side IGBT switches, motero.Kulowetsa kwa zowongolera za PWM ndi 9.5V, 60Hz sine carrier wave ndi 10V, 10kHz mafunde atatu atatu.