Hauv kev ntsuas hluav taws xob thiab kev saib xyuas, cov ntsuas hluav taws xob uas xav tau cov hloov hluav taws xob sab nraud (CTs) yog ubiquitous; lawv yog peb "qhov muag" kom paub qhov tseeb ntawm cov dej ntws loj. Txawm li cas los xij, muab zais rau hauv cov txheej txheem sophisticated no yog ib txoj cai hlau uas yuav tsum tau ua raws txhua lub sijhawm: ob sab ntawm lub tshuab hloov tam sim no yuav tsum tsis txhob ua haujlwm nrog qhib Circuit Court. Kab lus no yuav piav qhia txog cov hauv paus ntsiab lus thiab kev phom sij cuam tshuam.
Kev khiav hauj lwm hauv paus ntsiab lus ntawm tam sim no transformer
CT (Tam sim no Transformer) yog ib hom kev hloov pauv tshwj xeeb uas ua haujlwm raws li lub hauv paus ntsiab lus ntawm electromagnetic induction. Nws cov qauv tsim qauv tseem ceeb yog "txo tam sim no" thiab "kev cais tawm."
1. Cov qauv: Nws feem ntau muaj cov tub ntxhais hlau kaw, thawj winding nrog tsawg lem (txuas nyob rau hauv series nyob rau hauv lub ntsiab Circuit Court), thiab ib tug thib ob winding nrog ntau lem (txuas mus rau lub ntsuas hluav taws xob).
2. Lub Xeev Zoo: Hauv ib qho kev kaw kaw, CT ua haujlwm nyob rau hauv kwv yees li "luv-circuit" lub xeev. Raws li Ampere txoj cai Circuit Court thiab txoj cai ntawm electromagnetic induction, thawj tam sim no I1 yuav tsim ib qho alternating magnetic flux Φ nyob rau hauv cov tub ntxhais hlau, uas yuav induce ib tug tam sim no I2 nyob rau hauv lub thib ob sab. Kev sib raug zoo ntawm ob leeg yog raws li nram no:
Qhov twg N1 thiab N2 yog tus naj npawb ntawm lem nyob rau hauv thawj thiab thib ob windings, thiab kuv yog lub excitation tam sim no. Vim yog qhov loj heev excitation impedance thiab tsis tshua muaj me me hauv kev tsim, nws tuaj yeem yooj yim rau cov hauv qab no hauv cov xwm txheej zoo tagnrho:
Ntawm no, Kn hais txog qhov ntsuas kev hloov pauv, xws li 1000/5A. Nyob rau hauv cov ntaub ntawv no, cov tam sim no loj nyob rau hauv thawj sab yog precisely thiab proportionally hloov mus rau hauv ib tug me me tam sim no nyob rau hauv lub thib ob sab (feem ntau yog tus qauv tus nqi ntawm 5A los yog 1A) rau kev nyab xeeb ntsuas ntsuas. Tib lub sijhawm, lub peev xwm thib ob ntawm qhov tam sim no transformer (CT) yog qhov tsawg heev (feem ntau tsuas yog ob peb volts), nyob rau hauv qhov chaw nyab xeeb.
Txoj cai tsom xam thaum lub thib ob sab qhib
Thaum qhov thib ob Circuit Court qhib vim xoob terminals, cov xov hlau tawg, los yog kev sib tsoo thaum lub sij hawm sim, nws lub xeev kev khiav hauj lwm tau hloov pauv tsis zoo.
| Cov xwm txheej ua haujlwm | Ib txwm kaw | Kev qhib kev thib ob |
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Muaj, proportional rau I1 |
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Φ |
Ua tau zoo los ntawm cov demagnetizing flux tsim los ntawm I2, tswj cov qib qis | Poob ntawm inhibition, ceev saturation mus rau qhov tseem ceeb heev |
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Tsawg heev (ntau volts) | High voltage ntawm ntau txhiab lossis txawm kaum txhiab tus volts raug ntxias. |
| Lub cev yam | Kev sib txuas muaj zog, sib sib zog nqus tawm tswv yim: I2 tiv thaiv kev hloov pauv hauv Φ | Kev tawm tswv yim txiav tawm thiab lub zog sib xyaw ua ke: Tag nrho cov ampere tseem ceeb - tig I1 thiab N1 yog siv los ua kom muaj zog. |
Nws cov txheej txheem tseem ceeb ntawm lub cev yog raws li hauv qab no:
1: Kev Tsis Pom Zoo ntawm Demagnetizing Cov Lus Qhia
Thaum lub sijhawm ua haujlwm ib txwm muaj, qhov sib nqus flux tsim los ntawm theem nrab tam sim no I2 ib txwm nyob rau hauv qhov sib txawv ntawm qhov sib nqus flux tsim los ntawm thawj qhov tam sim no I1, tsim kom muaj zog "demagnetizing" nyhuv uas txwv cov sib nqus sib nqus flux hauv cov tub ntxhais hlau mus rau theem qis. Tom qab qhib Circuit Court, kuv 2=0, thiab cov nyhuv demagnetizing tam sim ntawd rov qab mus rau xoom.
2: Ceev ceev saturation ntawm magnetic flux
Cov thawj ampere tsis sib npaug - tig I1 thiab N1 tag nrho hloov mus rau hauv magnetizing ampere - tig. Since the core cross-sectional area is designed for low magnetic flux density, the core rapidly enters a deep saturation state at this point.
Raws li Faraday txoj cai ntawm electromagnetic induction, alternating magnetic flux yuav induce ib tug electromotive quab yuam nyob rau hauv winding. Thaum lub magnetic flux nce sharply, ib tug heev high voltage U2 yuav induced nyob rau hauv lub thib ob winding.
3: Generation ntawm kev kub siab
Nyob rau hauv lub hwj chim zaus tej yam kev mob, rau ib tug thawj tam sim no ntawm ntau pua amperes, qhov induced voltage ntawm lub qhib - Circuit Court ob sab yuav yooj yim mus txog ob peb txhiab volts, thiab nyob rau hauv heev mob, nws muaj peev xwm tshaj 10 kilovolts.
Lub teb chaws tus qauv GB/T 20840.2-2014 "Instrument Transformers - Part 2: Cov Kev Xav Tau Ntxiv rau Tam Sim No Transformers" muaj cov cai nruj heev rau kev ua haujlwm rwb thaiv tsev ntawm cov twj siv hluav taws xob, thiab qhov tam sim no qhov hluav taws xob siab dhau deb tshaj nws lub peev xwm tsim.
Kev puas tsuaj ntawm qhib Circuit Court nyob rau theem nrab ntawm tam sim no transformer
Lub high voltage thiab nrog phenomena generated los ntawm ib tug thib ob qhib Circuit Court yuav ua rau ib tug series ntawm saw tshua muaj xwm txheej.
1. Kev phom sij ntawm hluav taws xob poob siab: Ntau txhiab qhov hluav taws xob muaj hluav taws xob muaj nyob rau ntawm cov khoom siv thib ob, ncaj qha ua rau muaj kev pheej hmoo ntawm hluav taws xob poob siab. Kev tu thiab kho cov neeg ua haujlwm uas tau ntsib nrog qhov hluav taws xob no yam tsis muaj kev ceev faj yuav raug hluav taws xob poob siab.
2. Cov khoom puas tsuaj:
Rwb thaiv tsev tawg: Cov hluav taws xob siab yuav ua ntej ua txhaum ntawm inter-tig thiab inter- txheej rwb thaiv tsev ntawm cov cua ntsawj ntshab thib ob, lossis rhuav tshem cov rwb thaiv tsev rau hauv av nyob rau hauv lub voj voog thib ob, ua rau muaj kev puas tsuaj mus tas li rau qhov tam sim no transformer (CT).
Overheating thiab Burnout: Thaum cov tub ntxhais hlau muaj qhov txaus txaus, nws yuav tsim cov eddy tam sim no thiab hysteresis poob, ua rau cov tub ntxhais hlau overheat, uas yuav hlawv tawm lub rwb thaiv tsev winding thiab txawm ua rau hluav taws.
Hluav taws xob Arc thiab tawg: Qhib Circuit Court cov ntsiab lus (xws li xoob terminals) yuav ua kom muaj hluav taws xob txuas ntxiv nyob rau hauv high voltage. Qhov kub ntawm lub arc tuaj yeem hlawv cov khoom siv, ignites ib puag ncig combustibles, thiab lub siab - gases kub nyob rau hauv lub kaw txee tej zaum yuav ua rau hluav taws xob tawg.
3. Kev Ua Haujlwm Kev Nyab Xeeb
Kev ntsuas qhov tsis raug thiab tsis ua tiav: Rau CT- hom ntsuas hluav taws xob, xoom input tam sim no yuav ua rau lawv tsis tuaj yeem ntsuas hluav taws xob, ua rau poob hluav taws xob thiab muaj peev xwm daws teeb meem kev lag luam.
Generation of Dangerous High-Voltage Sparks: Qhov no tsis yog qhov hluav taws kub xwb, tab sis qhov ua rau muaj zog electromagnetic pulses tuaj yeem cuam tshuam nrog cov khoom siv hluav taws xob nyob ze.
Cov ntsiab lus
Ib qho qhib Circuit Court nyob rau sab thib ob ntawm lub tshuab hloov tam sim no ua rau muaj kev kub ntxhov ntawm lub zog hluav taws xob, thaum kawg ua rau muaj kev puas tsuaj rau lub cev uas tshwm sim raws li qhov siab voltage, muaj zog hluav taws xob arcs, thiab overheating. Yog li ntawd, nyob rau hauv tag nrho cov hauj lwm uas muaj xws li CT circuits, "qhib Circuit Court tiv thaiv" yuav tsum tau nruj me ntsis raws li ib tug txheej txheem.
Meanwhile, ob sab ntawm lub tam sim no transformer txuas nrog lub ntsuas hluav taws xob yuav tsum tau grounded. Qhov no, nrog rau "thov txwv tsis pub qhib lub voj voog ntawm ob sab," yog ob lub ntsiab lus tseem ceeb ntawm CT kev ua haujlwm thiab kev saib xyuas. Tom qab grounding, lub high voltage uas tau surged nyob rau hauv tau sai sai tawm mus rau hauv av los ntawm lub grounding hlau, zam cov khoom burnout los yog hluav taws xob shocks tshwm sim los ntawm ib tug cia li sawv nyob rau hauv lub thib ob sab muaj peev xwm.