Qhov kev sib tw tseem ceeb hauv kev xa hluav taws xob yog "yuav txo qis li cas." Raws li txoj cai ntawm physics, qhov poob ntawm tam sim no dhau los ntawm tus neeg xyuas pib yog ncaj qha proportional rau lub square ntawm tam sim no (P_loss=I²R). Txhawm rau kom tsis txhob poob, ib qho yuav tsum tau txo qhov kev tiv thaiv (los ntawm thickening tus neeg xyuas pib, uas yog kim heev) los yog txo qhov tam sim no. Txawm li cas los xij, tam sim no inversely proportional rau voltage (P=UI). Raws li lub hauv paus ntawm lub zog tas li, nce qhov hluav taws xob tuaj yeem txo qhov tam sim no -qhov no yog lub ntsiab lus tseem ceeb ntawm siab -voltage fais fab kis.
Lub sijhawm no, qhov sib txawv tseem ceeb ntawm kev hloov pauv tam sim no (AC) thiab ncaj qha tam sim no (DC) tuaj yeem pom meej: AC tuaj yeem yooj yim nce thiab qis dua voltage siv transformers, thaum DC tsis tuaj yeem ua qhov no tau ntev.
Lub zog hluav taws xob tsim los ntawm lub tshuab hluav taws xob (feem ntau nyob ib puag ncig 20kV) tuaj yeem nce mus rau ultra-siab voltages ntawm 110kV, 220kV, lossis txawm tshaj 1000kV los ntawm kauj ruam - nce transformer. Thaum kis tau mus ntev los ntawm cov kab sib kis, qhov tam sim no yog compressed mus rau qhov qis qis, thiab kev poob raug tswj nyob rau hauv ib qho kev pom zoo. Tom qab ncav cuag tus neeg siv kawg, qhov hluav taws xob tau nce ntxiv los ntawm kauj ruam -down transformer mus rau 220V (civilian) lossis 380V (kev lag luam), ua kom muaj kev nyab xeeb thiab yooj yim siv los ntawm cov khoom siv.
Qhov tsis muaj zog ntawm qhov ncaj qha tam sim no (DC) nyob hauv qhov nyuaj ntawm kev hloov pauv hluav taws xob. Nyob rau hauv thaum ntxov hnub, muaj ib tug tsis muaj peev xwm ntawm DC transformers. Yuav kom ua tiav siab -voltage DC kis tau tus mob, kev tswj qhov hluav taws xob yuav tsum tau ua los ntawm cov khoom siv kho tshuab nyuaj lossis cov khoom siv hluav taws xob kim, uas tsis yog tus nqi xwb tab sis kuj tsis tshua muaj kev ntseeg siab dua li cov khoom siv hluav taws xob. Qhov yooj yim zoo li "qhov teeb meem hloov pauv" ncaj qha txiav txim siab qhov tseem ceeb ntawm kev hloov tam sim no (AC) hauv daim phiaj hluav taws xob.
Thaum kawg, daim phiaj hluav taws xob xaiv qhov hloov pauv tam sim no (AC) vim tias nws daws tau qhov tseem ceeb ntawm "loj- nplai, ntev- nrug, thiab qis- nqi" fais fab kis.
