Ngā Āhuatanga o ngā Mīhini Tukutahi
Ko te mīhini tukutahi he momo mīhini hiko aukume (AC) e whakamahia whānuitia ana i roto i ngā pūnaha hiko hou, hei whakaputa hiko (alternator) me te motuka tukutahi. Ka kiia ko te "tukutahi" nā te mea he hononga pumau (tukutahi) te tere hurihuri o tōna hurihuri ki te auau pūtake AC. Ko te tikanga tēnei i raro i ngā āhuatanga mahi noa, ka mahi te mīhini tukutahi i te tere pumau e whakatauhia ana e te auau whatunga me te maha o ngā pou o te mīhini. Nā tēnei āhuatanga ka tino hira ngā mīhini tukutahi i roto i te whakaputa hiko me ngā tono ahumahi e hiahia ana ki te pumau o te tere me te kaha ki te whakahaere i te tauwehenga mana.
Te Whakamāramatanga me ngā Mātāpono Taketake o te Mahi
I te nuinga o te wā, e rua ngā wāhanga matua o tētahi mīhini tukutahi: te stator me te rotor. Ko te stator te wāhanga tūmau kei roto ngā koiri anga e whakaputahia ai, e tukuna ai rānei te ngaohiko AC. Ko te rotor te wāhanga hurihuri e whakaputa ana i te papa aukume. Ko te papa aukume o te rotor ka whakaputahia i te nuinga o te wā e te aukume tika (DC) mā roto i tētahi pūnaha whakaoho, ahakoa ka whakamahia pea e ētahi hoahoa hou he aukume tuturu.
Ko te kaupapa whakahaere e ahu mai ana i te taunekeneke o te papa aukume o te rotor me te papa aukume hurihuri i roto i te stator. I roto i te whakaputa hiko tukutahi, ko te rotor, e hurihia ana e te tāpine (kohu, wai, hau, tīhiera rānei), ka whakaputa i tētahi papa aukume e tapahi ana i ngā koiri stator, ka whakaputa i tētahi ngaohiko AC. I roto i te motuka tukutahi, ka "toia" e te papa aukume hurihuri o te stator te rotor, ka huri i te tere tukutahi.
Tere Tukutahi me tōna Hononga ki te Auautanga
Ko te āhuatanga tino motuhake o tētahi mīhini tukutahi ko te tere tukutahi (Ns). Ka whakawhirinaki tēnei tere ki te auau pūnaha (f) me te maha o ngā pou (P) o te mīhini, i hangaia penei:
Ns = (120 × f) / P
Nō reira, mō tētahi pūnaha 50 Hz:
– Mīhini pou-2: Ns = 3000 rpm
– Mīhini pou-4: Ns = 1500 rpm
– Mīhini pou-6: Ns = 1000 rpm
Ka noho pūmau tonu tēnei tere tukutahi mena he pūmau te auau. Kāore i rite ki ngā motuka whakaawe, e pāngia ana e te paheke, ko te pai o ngā motuka tukutahi he tika te huri i te Ns. He painga nui tēnei i roto i ngā tono e hiahia ana kia pumau te tere.
Hanganga me ngā Momo o te Rotor
Ka whakatauhia hoki ngā āhuatanga o tētahi mīhini tukutahi e te hoahoa o tōna rotor. E rua ngā momo rotor e kitea whānuitia ana:
1. Rotoru pou whakarara
He pou "e pūweru" ana. He mea whakamahi noa i roto i ngā miihini whakaputa hiko tere-iti, pērā i ngā tipu hiko wai, nā te mea he pai mō ngā tere-iti me te maha o ngā pou.
2. Rotorua porotaka (rotorua kore-kite, porotaka rānei)
He maeneene ake tōna āhua, he porotaka ake, he pai hoki mō ngā tere hurihuri teitei, pērā i ngā mea e kitea ana i roto i ngā tāwhana mamaoa i roto i ngā tipu hiko waro. E rua, e whā rānei ngā pou o tēnei rotor, ā, kua hangaia kia tū atu i te ahotea miihini nui e pā ana ki te hurihuri tere.
Pūnaha Whakaohooho me Ōna Pānga
Me whakaoho ngā mīhini tukutahi kia puta ai he papa aukume hurihuri (haunga ngā momo aukume tuturu). Ko tēnei whakaoho te āhuatanga matua e wehewehe ana i ngā mīhini tukutahi mai i te maha atu o ngā mīhini AC. Mā te whakarerekē i te ia whakaoho ka taea:
– Tautuhinga ngaohiko pūrua i runga i te whakaputa hiko
– Te tautuhinga ine mana i runga i te motuka
– Te whakahaere i te rere o te mana tauhohe (VAR) i roto i ngā pūnaha mana
I roto i ngā miihini tukutahi, mā te whakanui ake i te whakaoho ka piki ake te ngaohiko pito (me te whakaaro ki te kawenga me te tauhohenga). I roto i ngā miihini tukutahi, mā te whakanui ake i te whakaoho ka taea e te miihini te mahi me te tauwehenga mana ārahi, he mea whai hua mō te utu mana tauhohe.
Ngā Āhuatanga Ngaohiko me te Whakahaere Ngaohiko
I roto i ngā whakaputa hiko tukutahi, ko tētahi o ngā āhuatanga nui ko te whakahaere ngaohiko, arā, ko te huringa o te ngaohiko pito mai i te kore-kawenga ki ngā āhuatanga utaina i tētahi tere me te whakaohooho kua hoatu. Ka pāngia te whakahaere ngaohiko e:
– Te tauhohenga tukutahi (Xs)
– Ātete ki te koiri stator (Ra)
– Tauwehenga mana kawenga (whakaroa/arataki)
– He nui te au o te kawenga
Ka whakaitihia te ngaohiko pito e ngā kawenga ā-whakaoho (te tauwehe mana whakaroa) nā te hekenga o te ngaohiko puta noa i te tauhohenga. I tetahi atu taha, ka taea e ngā kawenga ā-pūmanawa (arahi) te whakapiki i te ngaohiko pito.
Ngā Āhuatanga Mana me te Koki Utaina
Ko ngā mīhini tukutahi e tohuhia ana e te whanaungatanga i waenga i te mana i tukuna me te koki mana δ, arā, te koki i waenga i te mara rotor me te mara stator. He māmā noa iho, ko te mana hikohiko i tukuna he rite ki te sin(δ). I te pikinga o te kawenga, ka piki te koki δ ki tētahi rohe. Mēnā he nui rawa a δ, ka ngaro pea te tukutahi o te mīhini (ka toia).
Koia te take he mea nui te pumau o te kokonga i roto i ngā pūnaha hiko, inā koa i te wā e raru ana te whatunga hiko. Me pupuri tonu ngā whakaputa hiko tukutahi ki te pūnaha, ki te kore ka whati pea hei tiaki i ngā taputapu.
Ngā Āhuatanga o te Tauwehe Mana i roto i ngā Mōta Tukutahi
Ko te painga ahurei o te motuka tukutahi ko tōna kaha ki te whakahaere i te tauwehenga mana mā te whakarerekē i te iahiko whakaoho. E toru ngā āhuatanga nui:
1. Kāore i te tino whakaohooho: he iti te iahiko whakaohooho, ka mimiti te motuka i te mana tauhohe (te tauwehe mana whakaroa).
2. Whakahihiri-noa: ka tata te tauwehenga mana ki te 1 (kotahitanga).
3. Nui rawa te whakaohooho: he nui te iahiko whakaohooho, ka tukuna e te motuka te mana tauhohe (te tauwehe mana matua).
Nā te mea ka taea e ia te mahi hei "whakakapinga", ka whakamahia te motuka tukutahi kua tino whakaohokia hei whakapūmau tukutahi, he taputapu hei whakapai ake i te tauwehe mana me te whakau i te ngaohiko pūnaha.
Tikanga Tīmata (Te Whakatakotoranga Porowhita Tuatahi)
Ko tētahi āhuatanga mahi o te motuka tukutahi ko te kore e taea te tīmata i a ia anō ina tukuna tika mai te mana AC, nā te mea he kore tōna taipana tīmatanga i raro i ētahi āhuatanga. Nō reira, me whai tikanga tīmatanga, hei tauira:
– Te whakamahi i tētahi mōtini āwhina (mōtini pōni)
– Te whakamahi i ngā takai amortisseur (ngā takai damper) kia mahi tuatahi ai pērā i te motuka whakapūmau, kātahi ka "raka" i te wā e tata ana ki a Ns
– Te whakamahi i te puku hiko/whakawhiti (mō ngā whakamahinga o ēnei rā)
Ka pā te tikanga tīmatanga ki te uauatanga o te pūnaha, te utu, me te pono o te whakahaere.
Te Whai Hua me te Whakamahinga
He nui te whai huatanga o ngā motuka tukutahi, inā koa i ngā kaha teitei. Ko ngā miihini whakaputa hiko tukutahi te pou tuara o te whakaputa hiko, ka taea te whakaputa i te nui o te hiko me te whakahaere ngaohiko tika. I roto i te ahumahi, ka whakamahia ngā motuka tukutahi i roto i:
– Pūhiko nui
– Papu me te pupuhi kaha teitei
– Ngā wheketere sima me te keri maina
– Ngā tono e hiahia ana kia tere tonu me te utunga mana pumau
Whakamutunga
Ko ngā āhuatanga o tētahi mīhini tukutahi ko te tere pumau e ai ki te auau, ngā whakaritenga whakaoho DC, ngā āheinga whakahaere i te tauwehenga mana, me te pumau tukutahi, he mea nui ēnei i roto i ngā pūnaha mana. I roto i tētahi kaihanga hiko tukutahi, he hononga tata te whakahaere whakaoho ki te whakahaere ngaohiko me te rere o te mana tauhohe. I roto i tētahi motuka tukutahi, ko te kaha ki te mahi i tētahi tauwehenga mana matua ehara i te mea he taraiwa kawenga miihini anake engari he taputapu whakapai ake i te kounga mana. Nā tōna whai huatanga teitei me tōna tūranga nui i roto i te whakaputa hiko me te ahumahi, kei te noho tonu ngā mīhini tukutahi hei wāhanga matua i roto i te whanaketanga o te hangarau mana hiko.
Ki te hiahia koe, ka taea e au te tāpiri i tētahi kauwhata ariā/wāhanga pikitia, he tauira o te tatau tere tukutahi, te hanga rānei i tētahi putanga hangarau ake o te tuhinga (me ngā whārite ara iahiko ōrite me ngā kōpiko-V o ngā motuka tukutahi).
