Momwe ma cell a dzuwa amagwirira ntchito

Maselo a dzuwa kuyamwa kuwala kwa dzuwa kupanga ntchito za mabatire wamba. Koma mosiyana ndi mabatire achikhalidwe, mphamvu yotulutsa mphamvu ndi mphamvu zambiri zotulutsa mabatire achikhalidwe zimakhazikika, pomwe magetsi otulutsa, apano, ndi mphamvu zama cell a solar zimagwirizana ndi kuyatsa komanso malo ogwiritsira ntchito. Chifukwa chake, kuti mugwiritse ntchito ma cell a solar kupanga magetsi, muyenera kumvetsetsa ubale womwe ulipo-voltage ndi mfundo yogwirira ntchito ya ma cell a dzuwa.

Kuwala kwa dzuwa:

Gwero lamphamvu la ma cell a solar ndi kuwala kwa dzuwa, kotero kulimba ndi kuchuluka kwa zochitika za dzuwa kumatsimikizira zomwe zikuchitika komanso mphamvu yamagetsi ndi cell ya solar. Timadziwa kuti chinthu chikaikidwa pansi pa dzuŵa, chimalandira kuwala kwa dzuwa m’njira ziwiri, imodzi ndi kuwala kwa dzuwa, ndipo ina imatuluka kuwala kwa dzuwa itamwazikana ndi zinthu zina pamwamba. Nthawi zambiri, kuwala kwachindunji kumakhala pafupifupi 80% ya kuwala komwe kumalandiridwa ndi cell solar. Chotero, kukambitsirana kwathu kotsatira kudzagogomezeranso kwambiri za kukhala padzuŵa.

Kuchuluka ndi kuchuluka kwa kuwala kwa dzuwa kumatha kuwonetsedwa ndi kuwala kwa sipekitiramu, komwe ndi mphamvu yowunikira pa unit wavelength pagawo lililonse (W/㎡um). Kuchuluka kwa kuwala kwa dzuwa (W/㎡) ndiye kuchuluka kwa mafunde onse owunikira. Kuwala kwa kuwala kwa dzuwa kumayenderana ndi malo opimidwa ndi mbali ya dzuŵa poyerekezera ndi dziko lapansi. Zili choncho chifukwa kuwala kwa dzuŵa kudzatengedwa ndi kumwazikana ndi mlengalenga musanafike pa dziko lapansi. Zinthu ziwiri za malo ndi ngodya zimayimiridwa ndi zomwe zimatchedwa air mass (AM). Pakuwunikira kwa dzuwa, AMO imatanthawuza momwe zinthu zilili mumlengalenga pomwe dzuŵa likuwala mwachindunji. Kuwala kwake kumakhala pafupifupi 1353 W/㎡, komwe kumakhala kofanana ndi kuwala komwe kumapangidwa ndi ma radiation akuda ndi kutentha kwa 5800K. AMI imatanthawuza momwe zinthu zilili padziko lapansi, pamene dzuŵa likuwala mwachindunji, mphamvu ya kuwala imakhala pafupifupi 925 W/m2. AMI.5 imatanthawuza momwe zinthu zilili padziko lapansi, pamene dzuŵa likuchitika pamtunda wa madigiri 45, mphamvu ya kuwala imakhala pafupifupi 844 W/m2. AM 1.5 nthawi zambiri amagwiritsidwa ntchito kuyimira kuwala kwadzuwa kwapakati pa dziko lapansi. Solar cell circuit model:

Kukakhala kulibe kuwala, selo la dzuwa limakhala ngati pn junction diode. Ubale wapano-voltage wa diode yabwino ukhoza kufotokozedwa ngati

Kumene ndikuyimira panopa, V imayimira mphamvu yamagetsi, Is ndi machulukitsidwe panopa, ndi VT=KBT/q0, pamene KB imaimira BoItzmann mosasintha, q0 ndi unit magetsi chaji, ndipo T ndi kutentha. Kutentha kwachipinda, VT=0.026v. Tiyenera kuzindikira kuti mayendedwe a Pn diode panopa amatanthauzidwa kuti akuyenda kuchokera ku P-mtundu kupita ku n-mtundu wa chipangizocho, ndipo zabwino ndi zoipa za voteji zimatanthauzidwa ngati mphamvu ya P-mtundu wa terminal. kuchotsa kuthekera kwamtundu wa n-terminal. Choncho, ngati tanthauzo ili likutsatiridwa, pamene selo la dzuwa likugwira ntchito, mtengo wake wamagetsi ndi wabwino, mtengo wake wamakono ndi woipa, ndipo IV curve ili mu quadrant yachinayi. Owerenga akuyenera kukumbutsidwa apa kuti zomwe zimatchedwa diode yabwino zimachokera kuzinthu zambiri zakuthupi, ndipo ma diode enieni mwachibadwa adzakhala ndi zinthu zina zopanda pake zomwe zimakhudza ubale wamakono wa chipangizocho, monga kugwirizanitsanso kwamakono, apa Tidzagonjetsa ' ndimakambirana kwambiri. Pamene selo la dzuwa likuwululidwa ndi kuwala, padzakhala photocurrent mu pn diode. Chifukwa njira yamagetsi yomangidwira pagawo la pn imachokera ku mtundu wa n kupita ku mtundu wa p, ma electron-hole awiriawiri opangidwa ndi kuyamwa kwa ma photon amathamangira kumapeto kwa mtundu wa n, pomwe mabowowo amathamangira ku p. - mtundu mapeto. Photocurrent yopangidwa ndi awiriwo idzayenda kuchokera ku n-mtundu kupita ku p-mtundu. Kawirikawiri, kutsogolo kwamakono kwa diode kumatanthauzidwa ngati kuyenda kuchokera ku p-mtundu kupita ku n-mtundu. Mwa njira iyi, poyerekeza ndi diode yabwino, photocurrent yopangidwa ndi selo ya dzuwa ikaunikiridwa ndi mpweya woipa. Ubale wapano wamagetsi a cell solar ndiye diode yabwino kuphatikiza IL yoyipa ya photocurrent, yomwe kukula kwake ndi:

Mwa kuyankhula kwina, pamene palibe kuwala, IL = 0, selo la dzuwa ndi diode wamba. Selo la dzuwa likafupikitsa, ndiye kuti, V = 0, nthawi yayitali ndi Isc = -IL. Ndiko kunena kuti, pamene selo la dzuwa ndilofupikitsa, mawonekedwe afupipafupi ndi photocurrent yopangidwa ndi kuwala kwa zochitika. Ngati selo la dzuwa ndi lotseguka, ndiye kuti, ngati I = 0, voteji yake yotseguka ndi:

Chithunzi 2. Chigawo chofanana cha selo la dzuwa: (a) popanda, (b) ndi mndandanda ndi shunt resistors. Izi ziyenera kutsindika apa kuti voteji yotseguka ndi mafupipafupi amakono ndi magawo awiri ofunikira a ma cell a solar.

Mphamvu yotulutsa mphamvu ya cell solar imapangidwa ndi magetsi ndi magetsi:

Mwachiwonekere, mphamvu yotulutsa mphamvu ndi selo la dzuwa si mtengo wokhazikika. Imafika pamtengo wokwera kwambiri pamalo ena ogwiritsira ntchito magetsi, ndipo mphamvu yotulutsa Pmax imatha kutsimikiziridwa ndi dp/dv=0. Titha kunena kuti voteji yotulutsa mphamvu yayikulu kwambiri ya Pmax ndi:

ndipo zotsatira zake ndi:

Mphamvu yayikulu kwambiri ya cell solar ndi:

Kuchita bwino kwa cell solar kumatanthawuza kuchuluka kwa cell ya solar yomwe imatembenuza Pin yamphamvu ya kuwala kwa chochitikacho kukhala mphamvu yayikulu yamagetsi, ndiko kuti:

Miyezo yamphamvu ya ma cell a solar imagwiritsa ntchito kuwala kofanana ndi kuwala kwa dzuwa komwe kumakhala ndi pin=1000W/㎡.

Moyesera, ubale wapano-voltage wa ma cell a solar sutsatira kwathunthu kufotokozera kwapamwambaku. Izi ndichifukwa choti chipangizo cha photovoltaic palokha chimakhala ndi zomwe zimatchedwa kukana komanso kukana kwa shunt. Pazinthu zilizonse zamtundu wa semiconductor, kapena kukhudzana pakati pa semiconductor ndi chitsulo, mosakayikira padzakhala kukana kwakukulu kapena kochepa, komwe kungapangitse kukana kwa mndandanda wa chipangizo cha photovoltaic. Kumbali ina, njira iliyonse yamakono yosiyana ndi Pn diode yabwino pakati pa ma electrode abwino ndi oipa a chipangizo cha photovoltaic idzayambitsa zomwe zimatchedwa kutayikira panopa, monga mbadwo-recombination panopa mu chipangizo. , pamwamba recombination panopa, chosakwanira m'mphepete kudzipatula kwa chipangizo, ndi zitsulo kukhudzana malowedwe mphambano.

Nthawi zambiri, timagwiritsa ntchito shunt resistance kuti titanthauze kutuluka kwa ma cell a dzuwa, ndiye kuti, Rsh=V/Ileak. Kuchuluka kwa kukana kwa shunt ndiko, kung'onozing'ono kwa kutayikira kumakhala. Ngati tilingalira za kukana kwa ma Rs ndi shunt resistance Rsh, ubale wapano-voltage wa cell solar ukhoza kulembedwa motere:

Titha kugwiritsanso ntchito gawo limodzi lokha, lotchedwa fill factor, kuti tifotokoze mwachidule zonse zomwe zimachitika pakukaniza mndandanda ndi kukana kwa shunt. kufotokozedwa ngati:

Ndizodziwikiratu kuti chinthu chodzaza ndi chokwera ngati palibe chotsutsa chamndandanda ndipo kukana kwa shunt kuli kosatha (palibe kutayikira pano). Kuwonjezeka kulikonse kwa kukana kwa mndandanda kapena kuchepa kwa shunt kukana kumachepetsa kudzaza. Mwa njira iyi,. Kuchita bwino kwa ma cell a solar kumatha kuwonetsedwa ndi magawo atatu ofunikira: voltage yotseguka ya Voc, Isc yaposachedwa yapano, ndi kudzaza factor FF.

Mwachiwonekere, kuti muwongolere magwiridwe antchito a cell solar, ndikofunikira kuti nthawi imodzi muonjezeke voteji yake yotseguka, mayendedwe amfupi (ndiko kuti, photocurrent), ndi kudzaza chinthu (ndiko kuti, kuchepetsa kukana ndi kutayikira kwapano).

Open circuit voltage and short circuit current: Potengera njira yapitayi, voteji yotseguka ya cell solar imatsimikiziridwa ndi photocurrent ndi cell saturated. Kuchokera pamalingaliro a semiconductor physics, voteji yotseguka ndi yofanana ndi kusiyana kwa mphamvu ya Fermi pakati pa ma elekitironi ndi mabowo m'dera lamalipiro. Ponena za machulukitsidwe a Pn diode yabwino, mutha kugwiritsa ntchito:

kufotokoza. pomwe q0 imayimira mtengo wa unit, ni imayimira chonyamulira chamkati cha semiconductor, ND ndi NA iliyonse imayimira kuchuluka kwa wopereka ndi wolandila, Dn ndi Dp iliyonse imayimira kuchuluka kwa ma electron ndi mabowo, mawu omwe ali pamwambawa akuganiza kuti n. - Mlandu womwe chigawo chamtundu ndi gawo la mtundu wa p zonse ndi zazikulu. Kawirikawiri, kwa maselo a dzuwa omwe amagwiritsa ntchito magawo a p-type, dera la n-mtundu ndi losazama kwambiri, ndipo mawu omwe ali pamwambawa ayenera kusinthidwa.

Tanena kale kuti pamene selo la dzuwa liwunikiridwa, photocurrent imapangidwa, ndipo photocurrent ndi yotsekedwa-yozungulira pakalipano mu mgwirizano wamakono-voltage wa selo la dzuwa. Apa tifotokoza mwachidule chiyambi cha photocurrent. Kuchuluka kwa zonyamulira mu voliyumu ya unit pa nthawi ya unit (unit m -3 s -1 ) kumatsimikiziridwa ndi coefficient ya kuyamwa kwa kuwala, ndiko kuti.

Pakati pawo, α imayimira kuchuluka kwa mayamwidwe a kuwala, komwe ndi mphamvu ya ma photon (kapena photon flux density), ndipo R amatanthauza coefficient yowonetsera, kotero imayimira mphamvu ya mafotoni a zochitika zomwe sizikuwonetsedwa. Njira zazikulu zitatu zomwe zimapanga ma photocurrent ndi: kufalikira kwa magetsi onyamula ma elekitironi ochepa m'chigawo cha p-mtundu, kufalikira kwa mabowo onyamula ochepa m'chigawo cha n-mtundu, komanso kutengeka kwa ma elekitironi ndi mabowo m'dera lamalipiro. panopa. Chifukwa chake, photocurrent imatha kufotokozedwa motere:

Pakati pawo, Ln ndi Lp iliyonse imayimira kutalika kwa ma elekitironi m'chigawo cha p-mtundu ndi mabowo m'chigawo cha n-mtundu, ndipo ndi m'lifupi mwa chigawo cha danga. Pofotokoza mwachidule zotsatirazi, timapeza mawu osavuta amagetsi otseguka:

pomwe Vrcc imayimira kuchulukanso kwa ma electron-hole pairs pa voliyumu ya unit. Inde, izi ndi zotsatira zachilengedwe, chifukwa lotseguka dera voteji ndi wofanana Fermi mphamvu kusiyana pakati ma elekitironi ndi mabowo mu danga mlandu dera, ndi Fermi mphamvu kusiyana pakati ma elekitironi ndi mabowo anatsimikiza ndi chonyamulira mlingo m'badwo ndi recombination mlingo. .