Lub lim tiam no peb txuas ntxiv nrog lub lim tiam dhau los tsab xov xwm.

1.2 Electrolytic capacitor

Lub dielectric siv nyob rau hauv electrolytic capacitors yog txhuas oxide tsim los ntawm corrosion ntawm txhuas, nrog ib tug dielectric tas li ntawm 8 mus rau 8.5 thiab ib tug ua hauj lwm dielectric zog ntawm txog 0.07V / A (1µm = 10000A).Txawm li cas los xij, nws tsis tuaj yeem ua tiav qhov tuab.Lub thickness ntawm txhuas txheej yuav txo tau qhov muaj peev xwm (tshwj xeeb capacitance) ntawm electrolytic capacitors vim hais tias cov txhuas ntawv ci yuav tsum tau etched los ua ib tug aluminium oxide zaj duab xis kom tau zoo zog cia cov yam ntxwv, thiab cov nto yuav tsim ntau yam tsis sib xws.Ntawm qhov tod tes, qhov resistivity ntawm electrolyte yog 150Ωcm rau tsawg voltage thiab 5kΩcm rau high voltage (500V).Qhov siab dua ntawm cov electrolyte txwv RMS tam sim no uas cov electrolytic capacitor tuaj yeem tiv taus, feem ntau yog 20mA / µF.

Rau cov laj thawj no electrolytic capacitors yog tsim los rau qhov siab tshaj plaws ntawm 450V raug (qee tus neeg tsim khoom tsim rau 600V).Yog li ntawd, txhawm rau kom tau txais cov hluav taws xob ntau dua nws yog qhov tsim nyog kom ua tiav lawv los ntawm kev txuas cov capacitors hauv koob.Txawm li cas los xij, vim tias qhov sib txawv ntawm rwb thaiv tsev tsis kam ntawm txhua tus electrolytic capacitor, lub resistor yuav tsum tau txuas nrog txhua lub capacitor txhawm rau sib npaug qhov voltage ntawm txhua series txuas nrog capacitor.Tsis tas li ntawd, electrolytic capacitors yog cov khoom siv polarized, thiab thaum cov ntaub ntawv rov qab siv hluav taws xob ntau dua 1.5 npaug Un, cov tshuaj tiv thaiv electrochemic tshwm sim.Thaum lub zog rov qab siv tau ntev txaus, lub capacitor yuav nchuav tawm.Txhawm rau zam qhov tshwm sim no, lub diode yuav tsum txuas nrog ib sab ntawm txhua lub capacitor thaum nws siv.Tsis tas li ntawd, qhov voltage surge resistance ntawm electrolytic capacitors feem ntau yog 1.15 zaug Un, thiab cov zoo tuaj yeem ncav cuag 1.2 zaug Un.Yog li cov neeg tsim qauv yuav tsum xav txog tsis yog tsuas yog lub xeev ua haujlwm tsis tu ncua tab sis kuj muaj qhov nce siab thaum siv lawv.Hauv cov ntsiab lus, cov lus sib piv hauv qab no ntawm zaj duab xis capacitors thiab electrolytic capacitors tuaj yeem kos, saib Fig.1.

2. Kev txheeb xyuas daim ntawv thov

DC-Link capacitors raws li cov ntxaij lim dej xav tau cov qauv tsim tam sim no thiab muaj peev xwm siab.Ib qho piv txwv yog lub ntsiab tsav lub cev muaj zog ntawm lub tsheb tshiab lub zog raws li tau hais hauv Fig.3.Nyob rau hauv daim ntawv thov no lub capacitor plays lub luag hauj lwm decoupling thiab lub Circuit Court nta ib tug siab khiav hauj lwm tam sim no.Zaj duab xis DC-Link capacitor muaj qhov zoo ntawm kev muaj peev xwm tiv taus cov kev khiav hauj lwm loj (Irms).Siv 50 ~ 60kW lub zog tshiab lub tsheb tsis ua piv txwv, cov tsis muaj raws li hauv qab no: kev khiav hauj lwm voltage 330 Vdc, ripple voltage 10Vrms, ripple tam sim no 150Arms @ 10KHz.

Ces qhov tsawg kawg nkaus hluav taws xob muaj peev xwm yog xam raws li:

Qhov no yog ib qho yooj yim rau kev siv rau zaj duab xis capacitor tsim.Piv txwv tias siv electrolytic capacitors, yog tias 20mA / μF raug txiav txim siab, qhov tsawg kawg nkaus capacitance ntawm electrolytic capacitors raug xam kom ua tau raws li cov lus qhia saum toj no:

Qhov no yuav tsum muaj ntau yam electrolytic capacitors nyob rau hauv parallel txuas nrog kom tau txais qhov capacitance no.

Hauv kev siv hluav taws xob ntau dhau, xws li lub teeb rail, hluav taws xob tsheb npav, subway, thiab lwm yam. Xav txog tias cov hwj huam no txuas nrog lub locomotive pantograph los ntawm pantograph, kev sib cuag ntawm pantograph thiab pantograph yog sib quas ntus thaum lub sij hawm thauj mus los.Thaum ob qho tib si tsis nyob rau hauv kev sib cuag, lub hwj chim mov yog txhawb los ntawm DC-L ink capacitor, thiab thaum cov kev sib cuag yog rov qab, lub overvoltage yog generated.Qhov xwm txheej phem tshaj plaws yog qhov tso tawm tag nrho los ntawm DC-Link capacitor thaum txiav tawm, qhov chaw tawm hluav taws xob sib npaug rau pantograph voltage, thiab thaum kev sib cuag tau rov qab los, qhov tshwm sim dhau-voltage yog yuav luag ob npaug ntawm qhov ntsuas kev ua haujlwm Un.Rau cov yeeb yaj kiab capacitors DC-Link capacitor tuaj yeem ua haujlwm yam tsis muaj kev xav ntxiv.Yog tias siv electrolytic capacitors, qhov dhau-voltage yog 1.2Un.Siv Shanghai metro ua piv txwv.Un = 1500Vdc, rau electrolytic capacitor xav txog qhov voltage yog:

Tom qab ntawd rau 450V capacitor yuav tsum tau txuas nrog hauv series.Yog tias zaj duab xis capacitor tsim siv hauv 600Vdc rau 2000Vdc lossis txawm 3000Vdc tau yooj yim ua tiav.Nyob rau hauv tas li ntawd, lub zog nyob rau hauv cov ntaub ntawv ntawm tag nrho tawm lub capacitor tsim ib tug luv luv Circuit Court tawm ntawm ob lub electrodes, tsim ib tug loj inrush tam sim no los ntawm DC-Link capacitor, uas feem ntau yog txawv rau electrolytic capacitors kom tau raws li qhov yuav tsum tau.

Tsis tas li ntawd, piv rau electrolytic capacitors DC-Link zaj duab xis capacitors tuaj yeem tsim kom ua tiav ESR qis heev (feem ntau qis dua 10mΩ, thiab txawm tias qis dua <1mΩ) thiab tus kheej inductance LS (feem ntau qis dua 100nH, thiab qee zaum qis dua 10 lossis 20nH) .Qhov no tso cai rau DC-Link zaj duab xis capacitor raug ntsia ncaj qha rau hauv IGBT module thaum thov, tso cai rau lub tsheb npav tuaj yeem ua ke rau hauv DC-Link zaj duab xis capacitor, yog li tshem tawm qhov xav tau rau IGBT absorber capacitor thaum siv zaj duab xis capacitors, txuag. tus tsim ib qho tseem ceeb ntawm cov nyiaj.Fig.2.thiab 3 qhia cov kev qhia tshwj xeeb ntawm qee yam ntawm C3A thiab C3B cov khoom.

3. Cov lus xaus

Thaum ntxov, DC-Link capacitors feem ntau yog electrolytic capacitors vim tus nqi thiab qhov loj me.

Txawm li cas los xij, electrolytic capacitors raug cuam tshuam los ntawm qhov hluav taws xob thiab tam sim no muaj peev xwm tiv taus (ntau dua ESR piv rau cov yeeb yaj kiab capacitors), yog li nws yog ib qho tsim nyog yuav tsum tau txuas ob peb electrolytic capacitors nyob rau hauv series thiab parallel thiaj li yuav tau txais lub peev xwm loj thiab ua tau raws li cov kev xav tau ntawm kev siv hluav taws xob siab.Tsis tas li ntawd, xav txog qhov volatilization ntawm cov khoom siv electrolyte, nws yuav tsum tau hloov tsis tu ncua.Kev siv hluav taws xob tshiab feem ntau xav tau cov khoom lag luam lub neej ntawm 15 xyoo, yog li nws yuav tsum tau hloov 2 mus rau 3 zaug hauv lub sijhawm no.Yog li ntawd, muaj tus nqi ntau thiab tsis yooj yim hauv kev pab cuam tom qab muag ntawm tag nrho lub tshuab.Nrog rau txoj kev loj hlob ntawm metallization txheej technology thiab zaj duab xis capacitor technology, nws tau ua tau los tsim high-capacity DC lim capacitors nrog voltage ntawm 450V mus rau 1200V los yog siab dua nrog ultra-thin OPP zaj duab xis (thinnest 2.7µm, txawm 2.4µm) siv. kev ruaj ntseg zaj duab xis vaporization technology.Ntawm qhov tod tes, kev sib koom ua ke ntawm DC-Txuas capacitors nrog lub npav npav ua rau lub inverter module tsim ntau compact thiab zoo heev txo cov stray inductance ntawm Circuit Court kom optimize Circuit Court.