Pehea ka hana ʻana o nā cell solar

pūnaewele lā e hoʻopaʻa i ka lā no ka hana ʻana i nā hana o nā ʻenekini maʻamau. Akā ʻaʻole e like me nā pākuʻi kuʻuna, ua paʻa ka mana hoʻopuka a me ka mana hoʻopuka kiʻekiʻe o nā pihi kuʻuna, ʻoiai ʻo ka volta hoʻopuka, kēia manawa, a me ka mana o nā cell solar e pili ana i nā kūlana kukui a me nā wahi hana. Ma muli o kēia, no ka hoʻohana ʻana i nā cell solar e hana i ka uila, pono ʻoe e hoʻomaopopo i ka pilina o kēia manawa-voltage a me ke kumu hana o nā cell solar.

Ka hoʻomālamalama ʻana o ka lā:

ʻO ke kumu ikehu o nā pūnaewele lā ʻo ia ka lā, no laila, ʻo ka ikaika a me ka spectrum o ka hanana ʻana o ka lā e hoʻoholo ai i ka hopena o kēia manawa a me ka volta e ka cell solar. Ua ʻike mākou i ka wā e waiho ʻia ai kekahi mea ma lalo o ka lā, loaʻa iā ia ka lā ma nā ʻano ʻelua, ʻo ka lā pololei o ka lā, a ʻo ka lā pālahalaha kekahi ma hope o ka hoʻopuehu ʻia e nā mea ʻē aʻe ma ka ʻili. Ma lalo o nā kūlana maʻamau, ʻike ʻia nā kukui hanana pololei ma kahi o 80% o ka mālamalama i loaʻa i kahi cell solar. No laila, ʻo kā mākou kūkākūkā e pili ana i ka ʻike pololei ʻana i ka lā.

Hiki ke hōʻike ʻia ka ikaika a me ka spectrum o ka lā e ka spectrum irradiance, ʻo ia ka mana māmā no kēlā me kēia ʻāpana hawewe lōʻihi ma kēlā me kēia ʻāpana (W/㎡um). ʻO ka ikaika o ka lā (W/㎡) ka huina o nā lōʻihi nalu o ka hoʻomālamalama spectrum. Pili ka hoʻomālamalama ʻana o ka lā i ke kūlana i ana ʻia a me ke kihi o ka lā e pili ana i ka ili o ka honua. ʻO kēia no ka mea e hoʻomohu ʻia ka lā a hoʻopuehu ʻia e ka lewa ma mua o ka hiki ʻana i ka ʻili honua. ʻO nā kumu ʻelua o ke kūlana a me ke kihi e hōʻike ʻia e ka mea i kapa ʻia ka air mass (AM). No ka hoʻomālamalama ʻana o ka lā, ʻōlelo ʻo AMO i ke kūlana ma waho i ka wā e alohi pololei ana ka lā. ʻO kona māmā māmā ma kahi o 1353 W/㎡, ua like ia me ke kumu kukui i hana ʻia e ka pāhawewe ʻeleʻele me ka mahana o 5800K. ʻO ka AMI e pili ana i ke kūlana ma ka ili o ka honua, i ka wā e hoʻomālamalama pololei mai ka lā, ʻo ka nui o ka mālamalama ma kahi o 925 W/m2. ʻO ka AMI.5 e pili ana i ke kūlana ma ka ʻili honua, i ka wā i hana ʻia ai ka lā ma kahi kihi o 45 degere, ʻo ka nui o ka mālamalama ma kahi o 844 W/m2. Hoʻohana ʻia ka AM 1.5 e hōʻike i ka awelika o ka mālamalama o ka lā ma ka ʻili honua. kŘkohu kaapuni kaapuni solar:

Inā ʻaʻohe kukui, ʻano like ka cell cell solar me ka diode junction pn. Hiki ke hōʻike ʻia ka pilina o kēia manawa-voltage o kahi diode kūpono

Ma kahi a'u e hoike ai i ke au, V hoike i ka volta, Is ka saturation au, a me VT=KBT/q0, kahi KB e hoike ana i ka BoItzmann mau, q0 ka wae uila, a o T ka wela. Ma ka wela lumi, VT=0.026v. Pono e hoʻomaopopo ʻia ke kuhikuhi ʻana o ka Pn diode i kēia manawa e kahe mai ka P-type a i ka n-type i loko o ka hāmeʻa, a ua wehewehe ʻia nā waiwai maikaʻi a maikaʻi ʻole o ka volta e like me ka P-type terminal potential. hōʻemi i ka hiki ke hoʻokuʻu ʻia n-type. No laila, inā e hahai ʻia kēia wehewehe ʻana, i ka hana ʻana o ka pūnaewele lā, maikaʻi kona waiwai voli, maikaʻi ʻole kona waiwai i kēia manawa, a ʻo ka pihi IV aia ma ka ʻehā quadrant. Pono e hoʻomanaʻo ʻia ka poʻe heluhelu ma aneʻi ʻo ka mea i kapa ʻia ʻo diode maikaʻi loa e pili ana i nā kūlana kino he nui, a e loaʻa maoli nā diodes maoli i kekahi mau mea nonideal e pili ana i ka pilina o kēia manawa-voltage o ka mea, e like me ka hanauna-recombination o kēia manawa, eia mākou e lanakila ' t kamailio nui. Ke ʻike ʻia ke kelepona lā i ka mālamalama, aia ka photocurrent i ka pn diode. No ka mea, mai ka n-type a hiki i ka p-type ke kuhikuhi kahua uila i kūkulu ʻia o ka hui pn, e holo ana nā lua electron-hole i hana ʻia e ka absorption o nā photons i ka hopena n-type, ʻoiai e holo ana nā puka i ka p. -type hope. ʻO ke kiʻi kiʻi i hana ʻia e nā mea ʻelua e kahe mai ka n-type a i ka p-type. ʻO ka mea maʻamau, ua wehewehe ʻia ka ʻaoʻao o mua o kahi diode e kahe ana mai ke ʻano p a i ke ʻano n. Ma kēia ala, i hoʻohālikelike ʻia me kahi diode maikaʻi, ʻo ka photocurrent i hana ʻia e kahi cell solar i ka wā e hoʻomālamalama ʻia he ʻano ʻino. ʻO ka pilina o kēia manawa-voltage o ka cell solar ka diode maikaʻi loa me kahi IL photocurrent maikaʻi ʻole, nona ka nui:

I nā huaʻōlelo ʻē aʻe, inā ʻaʻohe kukui, IL=0, he diode maʻamau ka cell solar. Ke kaapuni pōkole o ka lā, ʻo ia hoʻi, V=0, ʻo Isc=-IL ka ʻauamo pōkole. ʻO ia hoʻi, i ka wā pōkole o ka cell solar, ʻo ka manawa pōkole ʻo ia ka photocurrent i hana ʻia e ke kukui hanana. Inā he kaapuni hāmama ka pūnana lā, ʻo ia hoʻi, inā I=0, ʻo kona kaha kaapuni hāmama:

Kiʻi 2. Kaapuni like o ka cell solar: (a) me ka ʻole, (b) me ka moʻo a me nā pale pale shunt. Pono e hoʻokūpaʻa ʻia ma ʻaneʻi ʻo ka volta kaapuni wehe a me ke au kaapuni pōkole ʻelua mau ʻāpana koʻikoʻi o nā hiʻohiʻona cell solar.

ʻO ka hoʻopuka mana o kahi pūnana lā ka huahana o kēia manawa a me ka uila:

ʻIke loa, ʻaʻole i hoʻopaʻa ʻia ka mana hoʻopuka e ka solar cell. Hiki ia i ka waiwai kiʻekiʻe ma kekahi wahi hana o kēia manawa-voltage, a hiki ke hoʻoholo ʻia ka mana hoʻopuka kiʻekiʻe Pmax e dp/dv=0. Hiki iā mākou ke hoʻoholo i ka mana o ka mana puka Pmax:

a ʻo ka mea hoʻopuka i kēia manawa:

ʻO ka mana hoʻopuka kiʻekiʻe loa o ka cell solar:

ʻO ka maikaʻi o kahi pūnaewele lā e pili ana i ka ratio o ka cell solar e hoʻololi ana i ka mana Pin o ke kukui hanana i loko o ka mana uila kiʻekiʻe loa, ʻo ia hoʻi:

Hoʻohana ʻia ke ana ʻana o ka pono o ka lā ma ke kumu māmā e like me ka lā me ka pine=1000W/㎡.

ʻO ka hoʻāʻo ʻana, ʻaʻole pili loa ka pilina o kēia manawa-voltage o nā pūnaewele lā i ka wehewehe ʻana i luna. ʻO kēia no ka mea, ua kapa ʻia ka mea paʻi kiʻi kiʻi ponoʻī i ka series resistance a me ka shunt resistance. No kēlā me kēia mea semiconductor, a i ʻole ka pilina ma waena o kahi semiconductor a me kahi metala, ʻoi aku ka nui a i ʻole ka liʻiliʻi o ke kū'ē ʻana, ʻo ia ka mea e hana ai i ke kūpaʻa moʻo o ka mea photovoltaic. Ma kekahi ʻaoʻao, ʻo ke ala o kēia manawa ʻē aʻe ma mua o ka diode Pn maikaʻi ma waena o nā electrodes maikaʻi a maikaʻi ʻole o ka mea photovoltaic e hana i ka mea i kapa ʻia ka leakage au, e like me ka hanauna-recombination au i loko o ka hāmeʻa. , ka hoʻohui hou ʻana o ka ʻili i kēia manawa, ka hoʻokaʻawale lihi ʻole o ka hāmeʻa, a me ka hui komo ʻana metala.

ʻO ka mea maʻamau, hoʻohana mākou i ka pale shunt e wehewehe i ka leakage o kēia manawa o nā cell solar, ʻo ia hoʻi, Rsh=V/Ileak. ʻOi aku ka nui o ke kūpaʻa shunt, ʻoi aku ka liʻiliʻi o ke au leakage. Inā mākou e noʻonoʻo i ke kū'ē hui Rs a me ke kū'ē shunt Rsh, hiki ke kākau ʻia ka pilina o kēia manawa-voltage o ka cell solar e like me:

Hiki iā mākou ke hoʻohana i hoʻokahi wale nō parameter, ka mea i kapa ʻia ʻo fill factor, e hōʻuluʻulu i nā hopena ʻelua o ke kūpaʻa series a me ke kūpaʻa shunt. wehewehe penei:

ʻIke ʻia ʻoi aku ka kiʻekiʻe o ka mea hoʻopiha inā ʻaʻohe mea kūʻē kūʻai a ʻaʻohe palena o ka pale shunt (ʻaʻohe leakage current). ʻO ka piʻi ʻana o ke kūpaʻa series a i ʻole ka emi ʻana o ke kūpaʻa shunt e hōʻemi i ka mea hoʻopiha. Ma keia ano,. Hiki ke hōʻike ʻia ka maikaʻi o nā cell solar e nā ʻāpana koʻikoʻi ʻekolu: open circuit voltage Voc, short circuit current Isc, a me fill factor FF.

ʻIke loa, i mea e hoʻomaikaʻi ai i ka pono o ka cell solar, pono ia e hoʻonui i ka manawa like i kona hāmama kaapuni uila, pōkole kaapuni o kēia manawa (ʻo ia hoʻi, photocurrent), a me ka mea hoʻopiha (ʻo ia hoʻi, e hoʻemi i ke kūpaʻa series a me ka leakage o kēia manawa).

Kaapuni kaapuni wehe a me ka pōkole kaapuni o kēia manawa: I ka hoʻoholo ʻana mai ke kumu mua, ua hoʻoholo ʻia ka volta kaapuni hāmama o ka cell solar e ka photocurrent a me ka cell saturated. Mai ka hiʻohiʻona o ka semiconductor physics, ua like ka volta kaapuni hāmama me ka ʻokoʻa o ka ikehu Fermi ma waena o nā electrons a me nā lua ma ka ʻāpana hoʻoili lewa. E like me ke ʻano saturation o kahi diode Pn kūpono, hiki iā ʻoe ke hoʻohana:

e hoike aku. kahi q0 e hōʻike ana i ka huina hoʻoili, ʻo ni e hōʻike ana i ka neʻe ʻana o ka mea lawe i loko o ka semiconductor, ʻo ND a me NA kēlā me kēia e hōʻike ana i ka neʻe ʻana o ka mea hāʻawi a me ka mea ʻae, Dn a me Dp kēlā me kēia e hōʻike ana i ka diffusion coefficient o nā electrons a me nā lua, ua manaʻo ʻia ka ʻōlelo ma luna nei n - ʻO ka hihia kahi ākea o ka ʻāpana ʻano a me ka ʻāpana ʻano-p. ʻO ka mea maʻamau, no nā cell solar e hoʻohana ana i nā substrates p-type, pāpaʻu loa ka ʻano n-type, a pono e hoʻololi ʻia ka ʻōlelo ma luna.

Ua haʻi mua mākou i ka wā e hoʻomālamalama ʻia ai ka cell solar, e hana ʻia kahi kiʻi kiʻi, a ʻo ka photocurrent ke ʻano paʻa kaapuni i ka pilina o kēia manawa-voltage o ka cell solar. Maanei mākou e wehewehe pōkole ai i ke kumu o ka photocurrent. Hoʻoholo ʻia ka helu o ka hanauna o nā mea lawe i ka leo ʻāpana i kēlā me kēia manawa (unit m -3 s -1) e ka coefficient absorption māmā, ʻo ia hoʻi.

Ma waena o lākou, hōʻike ʻo α i ka coefficient absorption māmā, ʻo ia ka ikaika o nā photon hanana (a i ʻole photon flux density), a ʻo R e pili ana i ka coefficient noʻonoʻo, no laila e hōʻike ana i ka ikaika o nā kiʻi hanana i ʻike ʻole ʻia. ʻO nā ʻano hana nui ʻekolu e hoʻopuka ana i ka photocurrent, ʻo ia hoʻi: ke au diffusion o nā electrons lawe liʻiliʻi ma ka ʻāpana ʻano-p, ke ʻano diffusion o nā puka lawe liʻiliʻi ma ka ʻano n-type, a me ka neʻe ʻana o nā electrons a me nā lua ma ka ʻāpana hoʻoili lewa. kēia manawa. No laila, hiki ke hōʻike ʻia ka photocurrent penei:

Ma waena o lākou, ʻo Ln a me Lp kēlā me kēia e hōʻike ana i ka lōʻihi diffusion o nā electrons ma ka ʻāpana ʻano-p a me nā lua i ka ʻāpana n-type, a ʻo ia ka laulā o ka ʻāpana hoʻoili ākea. I ka hōʻuluʻulu ʻana i kēia mau hopena, loaʻa iā mākou kahi ʻōlelo maʻalahi no ka volta kaapuni hāmama:

kahi e hōʻike ai ʻo Vrcc i ka helu hoʻohui hou ʻana o nā pālua electron-hole no kēlā me kēia leo. ʻOiaʻiʻo, he hopena kūlohelohe kēia, no ka mea, ua like ka ʻokoʻa kaapuni ākea me ka ʻokoʻa o ka ikehu Fermi ma waena o nā electrons a me nā lua ma ka ʻāpana o ka lewa, a ʻo ka ʻokoʻa o ka ikehu Fermi ma waena o nā electrons a me nā lua e hoʻoholo ʻia e ka helu o ka hanauna lawe a me ka recombination rate. .