Ngā Whakawhiti i roto i ngā Whare Hiko Wai: Te Huri i te Ngaohiko mō te Tohatoha Pūngao
E mōhiotia ana ngā tipu hiko wai (PLTA) he puna hiko pono, whai hua, ā, he pai hoki mō te taiao. Heoi, kāore te angitu o tētahi tipu hiko wai e whakawhirinaki anake ki te wātea o te wai me te mahi a te pūkaha hiko-pūkaha. Kei muri i te tukanga whakaputa hiko, he wāhanga nui e āhei ai te tohatoha tika i te hiko kua whakaputaina ki ngā kāinga, ki ngā ahumahi, me ngā whare tūmatanui: ko te whakawhiti hiko. He mahi tā ngā whakawhiti hiko ki te whakarerekē i ngā taumata ngaohiko kia rite ki te tuku me te tohatoha tawhiti ki ngā kaihoko. E matapakihia ana e tēnei tuhinga ngā mahi, ngā momo, ngā mātāpono mahi, me te tūranga rautaki o ngā whakawhiti hiko i roto i ngā pūnaha hiko wai.
Te Tūranga o ngā Whakawhiti i roto i te Mekameka Hiko Wai
I te nuinga o te wā, ka tīmata te tipu hiko wai (PLTA) me te wai e rere ana i roto i te pene rakau, ka huri i te tāpine. Kātahi ka peia e te tāpine he pūkaha hiko hei whakaputa hiko. Ko te ngaohiko putanga o te pūkaha hiko wai (PLTA) he waenga (hei tauira, 6,6 kV, 11 kV, 13,8 kV, 20 kV rānei), i runga i te hoahoa o te tipu.
Ko te raruraru, ko te tuku hiko i te ngaohiko waenga i ngā tawhiti roa ka hua ake he ngaronga hiko nui. Koinei te wāhi e tino hira ai ngā whakawhiti hiko. Mā te whakanui ake i te ngaohiko (whakapiki ake), ka taea te whakaiti i te iahiko mō te mana kotahi, ā, ka whakaitihia ngā ngaronga i roto i ngā raina tuku hiko. Kia tae te hiko ki te pokapū kawenga, ka whakahekehia e tētahi atu whakawhiti hiko te ngaohiko ki te taumata haumaru, e tika ana mō te whatunga tohatoha me te whakamahinga a te kiritaki.
He aha me whakarerekē te hiko?
I roto i tētahi pūnaha hiko, ka taea te mārama ngāwari ki te mana hohe mā te whanaungatanga taketake:
P = V × I
Hei tuku i te mana P kotahi, ki te whakanuia te ngaohiko V, ka heke te iahiko I. Ko ngā ngaronga i roto i ngā kaiārahi tuku he mea whakamahana (ngā ngaronga) ko te nui he rite ki:
Ploss = I² × R
Ko te tikanga o tēnei, ki te whakaitihia te iahiko, ka heke te ngaronga i te taha whā. Nō reira, ko te whakanui ake i te ngaohiko he rautaki matua mō te tuku hiko tawhiti-roa whai hua. Ka taea e ngā whakawhiti hiko te whakahohe i tēnei tukanga me ngā ngaronga iti, ka taea ai e te pūnaha hiko te whakahaere ōhanga.
Te Mātāpono Mahi o te Whakawhitiwhiti
Ko te mahi a ngā whakawhiti hiko i runga i te aukume hikohiko. Ko ngā wāhanga matua o te whakawhiti hiko ko:
1. Koiri tuatahi: ka whiwhi hiko mai i tētahi pūtake (hei tauira, te whakaputa hiko).
2. Koiri tuarua: ka whakaputa i te ngaohiko putanga e hiahiatia ana.
3. Matua aukume: te ara rerenga aukume hei whakapakari i te hononga aukume i waenga i te tuatahi me te tuarua.
Ina rere te aukume whakawhiti (AC) mā te pōkai tuatahi, ka hangaia he rerenga aukume e huri haere ana i roto i te uho. Ka puta he ngaohiko i roto i te pōkai tuarua nā tēnei rerenga e huri haere ana. Ka whakatauhia te ōwehenga ngaohiko e te ōwehenga o te maha o ngā hurihanga:
V₁ / V₂ = N₁ / N₂
Mena he nui ake te maha o ngā takahuri tuarua i te tuatahi, ka piki ake te ngaohiko (whakapiki). Mena he iti iho, ka heke te ngaohiko (whakaheke). Nā te mea ka mahi ngā whakawhiti hiko i runga i te AC, ka taea te "whakawhiti" i te pūngao i waenga i ngā koiri me te kore e pā tika ki te hiko, ka pai ake hoki te haumaru me te wehe.
Whakawhiti Whakaara-Whakarunga i roto i te Teihana Hiko Waiora
Ko te momo whakawhiti hiko tino nui i roto i te tipu hiko wai ko te whakawhiti hiko whakarunga, e tū ana i roto i te papa whakawhiti hiko, i te teihana hiko rānei. Ko tana mahi he whakanui i te ngaohiko putanga o te kaihanga hiko ki te ngaohiko tuku, hei tauira, ki te 70 kV, 150 kV, 275 kV, tae atu ki te 500 kV, i runga i te pūnaha whatunga e whakamahia ana.
I tēnei wā, me hangaia te whakawhiti hiko kia tu atu ki ngā āhuatanga mahi uaua, tae atu ki:
– Ngā kawenga nui, me ngā kawenga tonu e ai ki te kaha o te whakaputa hiko.
– Ngā raruraru pūnaha pērā i te uira, ngā ngaru hiko, ngā ara iahiko poto rānei i roto i te whatunga.
– He nui ngā whakaritenga whakamarumaru nā te nui o ngā ngaohiko whakahaere.
– He whai hua te whakamatao nā te mea ka puta te wera i ngā ngaronga parahi me ngā ngaronga matua.
Ko ngā whakawhiti hiko i roto i ngā tipu hiko wai e whakamahi ana i te hinu whakawhiti hiko hei ārai me te whakamatao. Ka taea te whakamahi i te pūnaha whakamatao hei ONAN (Hinuhinu Taiao, Hau Taiao), ONAF (Hinuhinu Taiao, Hau Āwhina), OFAF rānei (Hinuhinu Āwhina, Hau Āwhina), i runga i te putanga hiko me ngā āhuatanga whakahaere.
Whirihoranga Whakaputa me te Whakawhiti Wāhanga
I roto i ngā tipu hiko wai nui, he maha ngā wā ka whakamahia he whirihoranga waeine whakaputa hiko-whakawhiti hiko, ina honoa tika tētahi whakaputa hiko ki tētahi whakawhiti hiko matua kotahi. Ka whakapai ake tēnei whirihoranga i te pono me te whakahaere i te tiaki, nā te mea kāore te pakaru o tētahi waeine e aukati i te tipu katoa.
Hei tāpiri, ka taea te whakamahi i ētahi atu taputapu whakawhiti hiko pēnei i:
– Pūwhakawhiti Ratonga Teihana: e whakarato ana i ngā hiahia o roto o te tipu hiko wai (ngā papu, ngā pūnaha whakahaere, te rama, te whakamatao, ngā takirere, me ētahi atu).
– Pūwhakawhiti Āwhina: e whakarato ana i ngā kawenga āwhina i te wā e tīmata ana, i te wā rānei kāore tētahi wāhanga e mahi ana.
– Pūwhakawhiti Whenua (i roto i ētahi whirihoranga): āwhina ki te whenua o te pūnaha me te pumau o te mahi.
Whakawhiti Whakaheke-Iho mō te Tohatoha Pūngao
I muri i te tukunga o te hiko i te ngaohiko teitei, ā, ka tae ki te rohe kawenga, me whakaiti haere te ngaohiko. Ka puta tēnei tukanga whakaheke hiko i ngā teihana tuku me te tohatoha hiko, kia tae rā anō ki te ngaohiko e whakamahia ana e ngā kiritaki, hei tauira:
– Ngaohiko tohatoha waenga: 20 kV, 11 kV rānei
– Ngaohiko iti mō te whare: 230/400 V (i runga i ngā paerewa ā-rohe)
Ahakoa kāore i te nuinga o te wā ka whakanohoia ngā whakawhiti hiko whakaheke-hiko ki ngā tipu hiko wai, he wāhanga tonu ēnei o te mekameka hiko e tīmata ana i te tipu hiko wai. Ki te kore he whakawhiti hiko tohatoha, kāore e taea te whakamahi haumaru i te hiko, me te hototahi ki ngā taputapu kaihoko.
Te Tiakitanga me te Pono o ngā Whakawhiti i roto i ngā Whare Hiko Wai
Nā te mea he utu nui ngā whakawhiti hiko, ā, he wāhanga nui hoki, he mea nui rawa atu ō rātou pūnaha tiaki. Ko ngā whakawhiti hiko wai te nuinga o te wā e rite ana ki:
– Te tānga Buchholz: ka kitea te hau nā ngā hapa o roto i ngā whakawhiti hinu.
– Te parenga rerekētanga (87T): ka kitea ngā rerekētanga o ngā iahiko tuatahi-tuarua e tohu ana i ngā hapa ā-roto.
– Te parenga i te nui o te au me te hē whenua: te parenga i ngā hē nui o te au me te hē whenua.
– Te aroturuki i te pāmahana: te aroturuki i te pāmahana o te hinu me ngā takai hei ārai i te wera nui.
– Ārai ngaru: ka tu atu ki ngā ngaru ngaohiko nā te uira, nā te whakawhiti rānei.
Haunga te tiakitanga, he mea nui te tiaki auau mō te roa o te ora o te whakawhiti hiko. Ko te whakamātautau kounga hinu (DGA—Dissolved Gas Analysis), te ine i te ātete whakamahana, ngā whakamātautau ōwehenga hurihanga, me ngā tirotiro pūnaha whakamatao he mahi noa hei ārai i ngā pakaru.
Te Whai Hua me te Pānga Ōhanga
He nui te whai huatanga o ngā whakawhiti hiko hou, he maha ngā wā kei runga ake i te 98–99% i raro i ētahi āhuatanga kawenga. Heoi, nā te mea ka mahi tonu ngā whakawhiti hiko, ahakoa he iti noa ngā mate ka pā nui ki te pūngao ā-tau me ngā utu whakahaere. Ko ngā momo mate matua e rua ko:
1. Te ngaronga o te matua: ka puta ahakoa kāore he kawenga, he pānga o te rauemi matua me te ngaohiko.
2. Te ngaronga o te parahi: ka piki ake i te kawenga nā te awe o te iahiko i roto i te takai.
I roto i te horopaki o ngā tipu hiko wai, e mahi pinepine ana hei whakaputa kawenga turanga, hei kaiwhakahaere kawenga rānei, he pānga nui ngā rautaki whakahaere mahi whakawhiti hiko—hei tauira, te whiriwhiri i te kaha tika me te whakarite i te whakamatao tino pai—ki te whai huatanga o te pūnaha whānui.
Whakamutunga
He wāhanga matua ngā whakawhiti hiko i roto i ngā tipu hiko wai, e hono ana i te tukanga whakaputa hiko ki ngā hiahia o te tuku me te tohatoha hiko. Mā te kaha ki te whakanui ake i te ngaohiko i te pito whakaputa (whakapiki-ake) me te tautoko i te whakahekenga ngaohiko tata ki te kaihoko (whakaheke-iho), ka whakarite ngā whakawhiti hiko i te tohatoha hiko whai hua, haumaru, me te pono. Haunga tā rātou mahi matua o te huri i te ngaohiko, me kaha hoki ngā whakawhiti hiko i roto i ngā tipu hiko wai ki te tu atu i ngā wero o te mahi taumaha, me te whakarato i te tiaki pakari, me te tautokona e te tiaki auau hei whakarite i te pono mō te wā roa.
Hei whakamutunga, ka "hanga" te hiko e ngā tāpine me ngā whakaputa hiko, engari ko ngā whakawhiti hiko te mea e āhei ai taua hiko ki te haere i ngā tawhiti roa, ā, kia whānuitia hoki te whakamahinga. Ki te kore he whakawhiti hiko, ka uaua te toro atu ki ngā hapori me te whai hua—ka waiho ngā whakawhiti hiko hei pou matua mō ngā pūnaha hiko hou.
