Ua rau, yam ntxwv thiab txwv txoj hauv kev ntawm Capacitor Switching Inrush Current

I. Ua rau Capacitor Switching Inrush Current

Qhov tseem ceeb ntawm capacitor hloov inrush tam sim no yog tias lub capacitor yog lub zog khaws cia, thiab qhov hluav taws xob hla nws cov terminals tsis tuaj yeem hloov pauv sai. Thaum lub sijhawm hloov mus, nws yog qhov sib npaug rau "capacitive load tau dheev txuas nrog lub voj voog" nrog lub voj voog tsis tshua muaj zog, ua rau muaj kev cuam tshuam loj tam sim no. Cov xwm txheej tshwj xeeb tau piav qhia raws li hauv qab no:

 

1. Thawj Hloov (Uncharged State): Thaum lub sij hawm ntawm thawj switching lag luam ntawm lub capacitor, nws daim hlau yog nyob rau hauv ib tug uncharged lub xeev, thiab cov thawj voltage nyob rau hauv lub terminals yog 0. Tom qab switching on lub sij hawm no, lub system voltage yog instantly thov mus rau ob kawg ntawm lub capacitor. Txij li thaum lub capacitor voltage tsis tuaj yeem hloov tam sim ntawd, qhov tam sim no them tam sim no yog tsim nyob rau hauv Circuit Court. Qhov tam sim no tsuas yog txwv los ntawm tag nrho lub voj impedance (xws li kab inductance, transformer to inductance, thiab lub capacitor tus kheej sib npaug series tsis kam ESR). Vim tias qhov sib npaug ntawm lub voj impedance yog qhov me me (ze rau luv luv -circuit state) thaum lub sijhawm hloov mus, qhov loj inrush tam sim no raug tsim. Qhov siab tshaj plaws inrush tam sim no feem ntau tshwm sim thaum lub sijhawm hloov pauv (txog rau theem ntawm qhov system voltage; thaum lub zog hluav taws xob nyob ze ntawm tus nqi siab tshaj thaum hloov mus, qhov inrush tam sim no amplitude kuj loj dua).

 

2. Re-hloov yam tsis muaj kev tso tawm txaus (Tshem Hloov Hloov): Yog tias lub capacitor rov ua dua - tsis muaj paug txaus tom qab raug txiav tawm thiab tshem tawm ntawm kev ua haujlwm, qhov amplitude ntawm qhov hloov pauv inrush tam sim no tuaj yeem ncav cuag ob npaug ntawm thawj qhov hloov pauv (lub xeev tsis them). Lub laj thawj tseem ceeb yog tias tom qab lub capacitor raug txiav tawm, cov nqi seem tseem nyob ntawm daim hlau (yog tias tsis tso tawm, qhov seem seem nyob ze rau qhov ntsuas theem voltage ntawm lub system). Thaum re- hloov mus, yog tias qhov system voltage thiab qhov seem voltage ntawm lub capacitor yog raws nraim nyob rau hauv ib qho kev hloov ntawm lub xeev ntawm "sib npaug zos loj thiab opposite direction", lub instantaneous muaj peev xwm sib txawv nyob rau hauv lub capacitor terminals yog ob zaug lub rated theem voltage, ua rau ib tug ntse nce nyob rau hauv them tam sim no thiab yog li ib tug loj hloov inrush tam sim no. Yog li ntawd, kom tsis txhob muaj kev puas tsuaj loj tam sim no rau cov khoom siv los ntawm kev hloov pauv, lub capacitor yuav tsum tau tso tawm tag nrho (feem ntau yog tawm mus rau qis dua qhov kev nyab xeeb hluav taws xob los ntawm qhov hluav taws xob tawm) ua ntej yuav rov qab - hloov tom qab raug txiav tawm thiab tshem tawm haujlwm.

 

II. Yam ntxwv ntsig txog Capacitor Switching Inrush Current

Lub amplitude ntau yam ntawm lub capacitor hloov inrush tam sim no feem ntau muaj feem xyuam rau ob yam: thawj, lub peev xwm ntawm lub capacitor txuas (qhov loj dua, qhov loj dua qhov inrush tam sim no amplitude feem ntau); thib ob, qhov luv - Circuit Court muaj peev xwm ntawm qhov chaw teeb tsa (qhov loj dua lub kaw lus luv luv - Circuit Court muaj peev xwm, qhov me dua qhov sib npaug lub voj inductance, qhov loj dua qhov inrush tam sim no amplitude thiab ntau dua oscillation zaus). Yog hais tias lub capacitor raug ntsia rau hauv ib lub voj voog nrog luv luv - Circuit Court muaj peev xwm, lub voj inductance me me thiab qhov impedance qis, yog li cov inrush tam sim no tsis tsuas yog muaj qhov loj amplitude tab sis kuj muaj qhov ntau dua oscillation zaus.

 

Ntsuas cov ntaub ntawv qhia tau hais tias nyob rau hauv ib tug pa system, lub amplitude ntawm lub capacitor hloov inrush tam sim no feem ntau yog 5 ~ 15 lub sij hawm tus nqi tam sim no ntawm lub capacitor (tus nqi tshwj xeeb yog cuam tshuam los ntawm lub voj tsis; piv txwv li, kev teeb tsa ntawm cov reactor series tuaj yeem txo qhov inrush tam sim no amplitude); Lub oscillation zaus ntawm qhov inrush tam sim no feem ntau yog 250 ~ 400Hz (nrog rau siab - zaus inrush tam sim no); Nyob rau tib lub sijhawm, qhov overvoltage tam sim no nrog rau lub sijhawm hloov pauv, thiab nws qhov amplitude yog kwv yees li 2 ~ 3 npaug ntawm qhov system theem voltage (qhov overvoltage no yog ib qho overvoltage nrog lub sijhawm luv luv, tab sis nws tseem yuav cuam tshuam rau lub capacitor rwb thaiv tsev).

Kev piav qhia ntxiv: Hauv cov tswv yim engineering, txhawm rau txhawm rau txhawm rau hloov pauv tam sim no, lub reactor me me (inrush tam sim no suppression reactor) feem ntau yog txuas nrog hauv cov kab hauv lub voj voog capacitor, uas tuaj yeem txwv qhov inrush tam sim no amplitude mus rau 2 ~ 5 npaug ntawm qhov ntsuas tam sim no, thiab tib lub sijhawm txo cov khoom siv overvoltage amplitude los tiv thaiv lub voj voog.

 

III. Txoj kev txwv Capacitor Hloov Inrush Tam Sim No

Kev khiav hauj lwm tam sim no ntawm lub capacitor tsis yog tsuas yog cuam tshuam nrog lub zog hluav taws xob hauv paus, tab sis kuj muaj feem cuam tshuam zoo rau qhov voltage zaus (raws li cov qauv ntawm cov tshuaj capacitive reactance X._C= 1/2πfC): thaum lub hwj chim mov voltage waveform yog distorted thiab siab - txiav txim harmonic voltage yog siv rau lub capacitor, txij li thaum lub harmonic zaus ntau dua li qhov tseem ceeb zaus, lub capacitive reactance ntawm lub capacitor yuav raug txo kom tsawg, ua rau ib tug ntau yam ntawm cov harmonica tam sim no dhau los ntawm lub capacitor. Nyob rau tib lub sijhawm, lub capacitor tam sim no kuj muaj txiaj ntsig zoo rau lub capacitance. Qhov loj dua qhov capacitance, qhov me me ntawm qhov capacitive reactance, thiab qhov loj dua qhov tam sim no (nrog rau qhov tseem ceeb tam sim no thiab kev sib haum xeeb tam sim no), uas ua rau muaj kev cuam tshuam ntawm qhov hluav taws xob waveform distortion thiab tsim lub voj voog vicious.

 

1. Kom ua tau zoo txwv lub capacitor hloov inrush tam sim no thiab suppress qhov cuam tshuam ntawm siab - xaj harmonics nyob rau hauv daim phiaj fais fab ntawm lub capacitor, txuas lub reactor nyob rau hauv series nyob rau hauv lub capacitor voj yog feem ntau siv thiab zoo txoj kev nyob rau hauv engineering. Nws lub hauv paus ntsiab lus yog:Jinneng hluav taws xob Iron-Core harmonic filter reactorsnce tag nrho cov inductive reactance ntawm Circuit Court, daim ntawv series resonance nrog lub capacitive reactance ntawm lub capacitor (rau tej yam harmonics), uas tsis tsuas yog txo cov paug tawm tam sim no thaum lub capacitor yog switched tab sis kuj inhibit qhov intrusion ntawm harmonic tam sim no. Yog tias qhov tsis sib xws ntawm cov reactor series raug xaiv kom raug, qhov hloov pauv inrush tam sim no tuaj yeem raug txwv tsis pub dhau qhov tso cai ntawm cov khoom siv.

Thaum cov reactor series tsuas yog siv los txwv kev hloov pauv tam sim no, nws lub peev xwm (reactance tus nqi) yuav tsum raug xaiv raws li tus nqi me me, feem ntau 0.2% ~ 1% ntawm lub peev xwm ntsuas ntawm lub capacitor (reactance tus nqi 0.2% ~ 1%). Kev lag luam kev lag luam thiab cov ntaub ntawv xeem qhia tau hais tias thaum lub reactor nrog ib tug series reactance tus nqi ntawm 0.2% yog kev cob cog rua, lub capacitor hloov inrush tam sim no muaj peev xwm heev suppressed kom tau raws li qhov yuav tsum tau ua ntawm cov khoom siv pa; yog tias kev sib haum xeeb (xws li suppressing 3rd thiab 5th harmonics) yuav tsum tau txiav txim siab tib lub sijhawm, tus nqi reactance tuaj yeem tsim nyog (xws li 3%, 5%).

 

2.Ntxiv rau lub reactor series, lub inrush tam sim no -free capacitor hloov pauv (xws lithyristor hloov) kuj yog ib qho uas nquag siv inrush tam sim no suppression ntaus ntawv. Hom kev hloov no feem ntau yog tsim los ntawm bidirectional thyristor, trigger circuit, absorption circuit, tiv thaiv Circuit Court, thiab ntse cua kub dab dej. Kev cia siab ntawm tus kheej patented xoom-voltage switching-on thiab xoom-tam sim no switching-tawm thev naus laus zis, nws tuaj yeem paub txog tam sim no inrush-dawb thiab cuam tshuam- pub dawb hloov ntawm cov capacitors, nrog cov lus teb ceev ceev thiab lub sijhawm teb nruab nrab ntawm tsawg dua 10ms. Nws tuaj yeem them rov qab zoo rau qhov kev xav tau ntawm lub zog reactive ntawm kev cuam tshuam, thiab tuaj yeem hloov tau cov khoom siv hloov pauv ib txwm muaj, zam qhov cuam tshuam arc thiab cuam tshuam qhov teeb meem tam sim no thaum lub sijhawm hloov pauv.