Transformer bushing CTs yuav tsum tau sim siv Current Ratio test method ua ntej lub transformer tau sib sau ua ke. CTs yuav tsum tau sim ua ntej lawv yuav tsum tau mounted ntawm lub transformer. Qee qhov xwm txheej, CTs yuav tsum tau sim los ntawm kev sib txuas cov kev xeem ua rau ob qho kawg ntawm qhov chaw teeb tsa. Qhov no tuaj yeem nyuaj! Yog tias cov CTs twb tau teeb tsa hauv lub tshuab hloov pauv, qhov loj (siab-muaj peev xwm) cov kev ntsuas tam sim no tuaj yeem rub los ntawm cov chaw CT ua ntej bushings tau muab tso rau. Qee zaus nws tsis tuaj yeem ua qhov ntsuas ntsuas tam sim no. CT kais piv piv tuaj yeem txheeb xyuas tau los ntawm kev siv qhov hluav taws xob hla tag nrho CT winding - Tap Voltage Ratio test -- tom qab ntawd ntsuas qhov hluav taws xob poob hla txhua tus kais. Qhov no yog ib qho kev sim yooj yim los ua, thiab qhov sib piv ntawm qhov voltage yuav ncaj qha mus rau CT lem piv ntawm cov kais dej.
Qhov kev ntsuas ntsuas qhov ntsuas qhov ntsuas qhov ntsuas no, txawm li cas los xij, yuav tsum tsis txhob xaiv los ua qhov hloov pauv rau qhov ntsuas tam sim no. Txoj kev voltage yuav tsum raug suav tias yog qhov kawg lwm txoj hauv kev. Kev ntsuam xyuas cov cuab yeej ntawm cov ntsuas tam sim no muaj kev lees paub ntau dua tias nws yuav ua tau raws li qhov xav tau thaum muab tso rau hauv kev pabcuam. Txoj kev piv txwv tam sim no qhia txog lub tswv yim no; Txoj Kev Tap Voltage Ratio tsis yog. Txoj Kev Tap Voltage tsis tuaj yeem tsim qhov tseeb kev taw qhia (polarity) ntawm cov CT ntsia, lossis sim thawj qhov piv rau theem nrab tam sim no, thiab tawm qee cov ntsiab lus tsis tau lees paub.
Ntxiv nrog rau Tap Voltage Ratio, qhov ntsuas thib ob Tap Current Ratio tuaj yeem ua tau. Rau qhov kev ntsuam xyuas no, ntsuas los yog tsawg dua tam sim no yog txhaj los ntawm tus kais tawm tswv yim thiab cov zis tam sim no ntawm tag nrho CT winding yog ntsuas los ntawm kev ua haujlwm ntawm transformer. Nws yog sib npaug rau cov txheej txheem siv los ua qhov Short-Circuit Impedance test ntawm autotransformer.
Nws tseem yog ib qho tseem ceeb kom paub tseeb CT polarity. Ib txoj hauv kev siv los tsim CT polarity hauv lub zog hloov hluav taws xob feem ntau hu ua "Flashing the CTs." Qhov kev sim no tuaj yeem ua tau los ntawm kev siv 6- rau -12 volts DC rau lub tshuab hloov pauv, siv lub pas kub kub rau
ua thiab tawg qhov kev xeem Circuit Court. Lub tsheb roj teeb feem ntau yog qhov yooj yim tshaj plaws vim tias cov tsheb ua haujlwm feem ntau muaj nyob ntawm qhov chaw ua haujlwm, tab sis lub teeb roj teeb yuav ua haujlwm zoo ib yam. Lub transformer winding kuj yog feem ntau txaus los txwv qhov tam sim no ntws los ntawm ib tug 12-volt tsheb roj teeb, tab sis ntxiv series (tam sim no-limiting) kuj (lub thawv load) rau lub xeem Circuit Court yog advisable nyob rau hauv tej kev xeem Circuit Court nrog ib tug automotive. roj teeb.
Nco ntsoov tias DC qhov ntsuas hluav taws xob yuav tsim kom muaj hluav taws xob ncaws thaum txiav tawm. Ceev faj kom tsis txhob muaj hluav taws xob poob. Yog tias ua qhov kev sim no ncaj qha rau ntawm CTs, ib txwm suav nrog qhov kev txwv tam sim no (lub thawv thauj khoom) hauv cov kev sib txuas ntawm flash. Teeb
Cov roj teeb muaj kev ua haujlwm siab sab hauv thiab tsis xav tau ib qho ntxiv series resistor. Arc flash ntawm lub hwj chim transformer tuaj yeem raug txwv yog tias lub transformer windings luv luv-circuited ntawm sab opposite cov uas raug flashed los ntawm
Rau CT qhov tseeb thiab kev ua tau zoo, flashing tej zaum yuav tsis yog qhov kev sim uas xav tau los ua vim tias qhov xwm txheej ntawm cov hlau nplaum seem hauv CT core tuaj yeem ua rau. Hauv txoj kev xav, qhov tshwm sim tuaj yeem yog qhov ua haujlwm tsis raug vim yog CT saturation thaum pib lub zog. Yog tias ua tau, demagnetizing cov tub ntxhais yog pom zoo tom qab kuaj DC flash siv lub siab tam sim no. Qhov seem tshuav raug tshem tawm los ntawm kev maj mam siv AC ntsuas tam sim no (excitation tam sim no) mus rau qhov tseem ceeb tam sim no, lossis AC qhov ntsuas hluav taws xob mus rau qhov qis tam sim no theem nrab (excitation voltage), thiab yuam cov CT cia li mus rau hauv saturation nrog lub thib ob qhib circuited. Tom qab maj mam txo cov AC kom muaj nuj nqis los ntawm qhov taw tes saturation mus rau xoom, cov dej seem seem yuav raug tshem tawm ntawm lub hauv paus (nws yuav raug demagnetized).