Txoj Kev Txiav Txim thiab Kev Tiv Thaiv rau Peb-theem Unbalance (1)
Peb-theem tsis sib npaug yog qhov tseem ceeb qhia txog lub zog zoo. Txawm hais tias muaj ntau yam cuam tshuam rau lub zog hluav taws xob, feem ntau ntawm qhov tsis sib xws yog vim muaj peb-theem Cheebtsam, kab tsis muaj lossis thauj khoom asymmetry. Vim hais tias qhov tseem ceeb ntawm peb-theem load tsis yog qhov tseeb, peb-theem voltage thiab tam sim no ntawm lub hwj huam mov taw tes yog nquag mus rau unbalance thiab poob ntawm kab. Tsis tas li ntawd xwb, nws tseem yuav cuam tshuam rau lub cev muaj zog ntawm cov khoom siv hluav taws xob, ua rau muaj kev puas tsuaj rau lub cev muaj zog. Yog li ntawd, yog tias peb-theem tsis sib npaug tshaj qhov ntau ntawm cov khoom xa tawm tuaj yeem dais, kev ua haujlwm nyab xeeb ntawm tag nrho lub zog hluav taws xob yuav raug cuam tshuam.
(1) Lub tswv yim tseem ceeb ntawm peb theem tsis sib npaug
Peb-theem unbalance yog hais txog qhov tsis sib xws ntawm peb-theem tam sim no (lossis voltage) amplitudes hauv lub zog hluav taws xob, thiab qhov sib txawv amplitude tshaj qhov kev teev tseg. Vim lub load tsis sib npaug ntxiv los ntawm txhua theem fais fab mov, nws belongs rau lub hauv paus yoj load configuration teeb meem. Qhov tshwm sim ntawm peb-theem tsis sib npaug yog cuam tshuam nrog tus neeg siv cov yam ntxwv ntawm kev thauj khoom, nrog rau kev npaj thiab thauj khoom ntawm lub zog hluav taws xob. Hauv cov kab hluav taws xob hluav taws xob, peb-theem sib npaug feem ntau txhais tau hais tias peb-theem voltage phasors sib npaug, thiab yog tias lawv tau teeb tsa hauv qhov kev txiav txim ntawm A, B, thiab C, lub kaum sab xis tsim ntawm lawv yog 2n / 3.
Peb-theem imbalance yog hais txog qhov tsis sib xws ntawm phasor loj thiab lub kaum sab xis. "Peb-theem voltage tso cai tsis sib npaug ntawm lub zog zoo" (GB / T15543-1995) muaj feem xyuam rau AC rated zaus ntawm 50 Hz. Tus txheej txheem teev tseg tias tus nqi tso cai ntawm qhov tsis sib npaug hauv kev ua haujlwm ib txwm muaj ntawm cov pej xeem kev sib txuas ntawm lub zog hluav taws xob yog 2 feem pua, thiab nws yuav tsum tsis pub tshaj 4 feem pua hauv lub sijhawm luv luv.
Txoj kev suav peb-theem tam sim no tsis sib npaug feem ntau muaj ob qho qauv siv hauv qab no:
Unbalance feem pua =(qhov siab tshaj tam sim no-tsawg kawg tam sim no) / siab tshaj tam sim no × 100 feem pua
Tsis sib npaug feem pua =(MAX theem tam sim no-peb-theem nruab nrab tam sim no) / peb-theem nruab nrab tam sim no × 100 feem pua
piv txwv:
Peb theem tam sim no yog IA=9A IB=8A IC=4A, tom qab ntawd peb theem nruab nrab tam sim no yog 7A, thiab theem tam sim no-peb-theem nruab nrab tam sim no yog 2A , 1A, thiab 3A, feem, qhov twg muaj qhov sib txawv loj tshaj plaws. Yog li ntawd, MAX (theem tam sim no - peb-theem nruab nrab tam sim no)=3A, yog li peb theem tam sim no tsis sib npaug=3/7.
