He aha ka Total Harmonic Distortion (THD)?
ʻO ka Total Harmonic Distortion (THD) he pilina hana-frequency e kōkua ana i ka helu ʻana i ka nui o ka hoʻopuka ʻana o ka ʻōnaehana i kahi hoʻokomo kope. . He ana ia o ka distortion harmonic i loko o kahi hōʻailona a ua wehewehe ʻia ʻo ia ka ratio o ka huina o nā mana o nā ʻāpana harmonic āpau i ka mana o ke alapine kumu. E pili ana kēia i nā lako mana wale nō a ʻo lākou wale nō ka mea e hana ai i kēlā me kēia ʻano alapine. ʻO ka haʻahaʻa o ka waiwai THD, ʻoi aku ka liʻiliʻi o ka walaʻau a i ʻole ka distortion i ka hoʻopuka ʻōnaehana.
No kēlā me kēia alapine ho'āʻo, aia ka waiwai o THD ma waena o 0 a me 1:
ZERO - ʻO ke kumu waiwai kokoke i ka ʻaʻole, ʻo ia ka haʻahaʻa haʻahaʻa o ka harmonic distortion. Loaʻa i ka hawewe sine puka ka ʻāpana alapine e like me ka hoʻokomo.
KEKAHI - ʻO kahi waiwai kokoke i ka 1 ʻo ia ka nui o ka distortion harmonic i ka hōʻailona. ʻOkoʻa nā ʻike alapine a pau i ka hōʻailona mai ke alapine o ka hōʻailona hoʻokomo.
Hiki ke hōʻike ʻia ʻo THD ma ke ʻano he pākēneka, mai 0 a 100%, kahi e pili ai ka 100% me 1.
I nā noi he nui, koi ʻia ka THD haʻahaʻa. ʻO ka THD haʻahaʻa, ʻo ia ka mea e like ka hoʻopuka ʻana o ka ʻōnaehana me ka hoʻokomo ʻana i ka ʻōnaehana me ka liʻiliʻi o ka distortion.
No ke aha he mea nui ia?
ʻO ka mea mua, ma ke ʻano he wehewehe ʻana, ʻo nā harmonics nā volta a i ʻole nā au i ka nui o ke alapine kumu, a ʻo Australia ʻo 50 Hz: 100, 150, 200 Hz, a pēlā aku. ke alapine kumu i loaʻa i nā lako uila a me nā lako uila nonlinear.
ʻO nā alakaʻi alakaʻi LED nā kumu mana uila i nā luminaires LED i loaʻa nā mea inductive (reactance a me nā ʻāpana capacitive). He mau mea laina ʻole lākou no ka mea, hoʻololi lākou i ke ʻano nalu o kēia manawa i huki ʻia mai ka hōʻailona uila i hāʻawi ʻia a ʻike ʻia he sinusoidal liʻiliʻi.
Hoʻokomo pū ka hapa nui o nā mea hoʻokele LED i kahi alahaka diode no ka hoʻoponopono ʻana i ka hōʻailona hoʻokomo AC e hana i ka module DC LED. ʻO ka hana hoʻololi ʻana o kēia mau alahaka diode e hoʻopuka i kahi au i hoʻopau ʻia e hoʻohuli i ka nalu sine.
No laila, ke hoʻopili ʻia ka mea hoʻokele LED i ka ʻōnaehana mana nui, hana ia i nā au harmonic e hoʻohuli i ka volta hāʻawi. A ʻoi aku ka nui o nā luminaires (me nā mea hoʻokele LED non-linear) i ke kaapuni, ʻoi aku ka nui o ka hoʻopili ʻana i ka ʻōnaehana hoʻoili mana, e hana ʻole ai, e pili ana i ka hana ʻana o nā mea ʻē aʻe a me ka hoʻoulu ʻana i ka uea.
ʻO kēia ke kumu e koi pinepine ai nā kikoʻī uila o nā lako kukui i nā hoʻonohonoho hou i ka nui o ka THD o ka luminaire ma lalo o 15%.