Svondo rino tinoenderera mberi nenyaya yesvondo rapfuura.

1.2 Electrolytic capacitors

Dielectric inoshandiswa mu electrolytic capacitors ialuminium oxide inoumbwa nekuora kwealuminium, ine dielectric constant ye8 kusvika 8.5 uye inoshanda dielectric simba inosvika 0.07V/A (1µm=10000A).Zvisinei, hazvibviri kuwana kukora kwakadaro.Ukobvu hwealuminium layer inoderedza huwandu hwesimba (chaiyo capacitance) ye electrolytic capacitor nekuti iyo aluminium foil inofanirwa kusungirirwa kuti iite aluminium oxide firimu kuti iwane yakanaka yekuchengeta simba maitiro, uye pamusoro inogadzira nzvimbo dzakawanda dzisina kuenzana.Nekune rimwe divi, resivisheni ye electrolyte i150Ωcm pa low voltage uye 5kΩcm pahigh voltage (500V).Kukwirira kwepamusoro kwe electrolyte kunomisa RMS yazvino iyo electrolytic capacitor inogona kumira, kazhinji kusvika 20mA/µF.

Nezvikonzero izvi maelectrolytic capacitor akagadzirirwa kukwirisa voltage ye450V yakajairika (vamwe vagadziri vega vanogadzira 600V).Naizvozvo, kuti uwane ma voltages epamusoro zvinodikanwa kuti uzviwane nekubatanidza capacitor munhevedzano.Nekudaro, nekuda kwemusiyano wekupokana kwekudzivirira kweyega yega electrolytic capacitor, chinopikisa chinofanira kunge chakabatana kune yega yega capacitor kuitira kuti ienzane nemagetsi ega ega akateedzana capacitor.Uye zvakare, electrolytic capacitors midziyo yepolarized, uye kana iyo inoshandiswa reverse voltage inodarika 1.5 times Un, electrochemic reaction inoitika.Kana iyo inoshandiswa reverse voltage yakareba zvakakwana, capacitor inobuda kunze.Kuti udzivise chiitiko ichi, diode inofanira kubatanidzwa pedyo nega yega capacitor kana inoshandiswa.Kunze kwezvo, voltage surge resistance ye electrolytic capacitors inowanzoita 1.15 times Un, uye yakanaka inogona kusvika ka1.2 Un.Saka vagadziri havafanire kufunga kwete chete yakatsiga-mamiriro ekushanda voltage asiwo magetsi ekuwedzera kana uchivashandisa.Muchidimbu, tafura yekuenzanisa inotevera pakati pefirimu capacitors uye electrolytic capacitors inogona kutorwa, ona Fig.1.

2. Kuongorora Kwekushandisa

DC-Link capacitors semafirita inoda yakakwirira ikozvino uye yakakwirira dhizaini magadzirirwo.Muenzaniso ndiyo huru yemotokari yemotokari yemotokari itsva sezvakataurwa muFig.3.Muchishandiso ichi capacitor inotamba decoupling basa uye dunhu rinoratidza yakakwira inoshanda ikozvino.Iyo firimu DC-Link capacitor ine mukana wekukwanisa kushingirira mahombe ekushanda (Irms).Tora 50 ~ 60kW itsva simba motokari parameters semuenzaniso, parameters ndeyotevera: kushanda voltage 330 Vdc, ripple voltage 10Vrms, ripple current 150Arms@10KHz.

Ipapo hushoma hwemagetsi huwandu hunoverengerwa se:

Izvi zviri nyore kushandisa firimu capacitor dhizaini.Tichifunga kuti electrolytic capacitor inoshandiswa, kana 20mA/μF ikatariswa, hushoma hwekugona kwe electrolytic capacitors hunoverengerwa kusangana nepamusoro apa paramita sezvinotevera:

Izvi zvinoda akawanda electrolytic capacitor mune parallel akabatana kuti uwane iyi capacitance.

In over-voltage applications, senge njanji yakareruka, bhazi remagetsi, subway, etc. Tichifunga kuti masimba aya akabatana nelocomotive pantograph kuburikidza nepantograph, kusangana pakati pepantograph uye pantograph kunopindirana panguva yekufambisa kwekufambisa.Kana vaviri vacho vasingabatanidzi, simba rekushandisa rinotsigirwa neDC-L ink capacitor, uye kana kusangana kwadzorerwa, iyo-over-voltage inogadzirwa.Nyaya yakaipisisa ndeyekubudiswa kwakakwana neDC-Link capacitor kana yakadzimwa, apo magetsi ekubuda akaenzana nemagetsi epantograph, uye kana kubatwa kwadzorerwa, kuguma kwepamusoro-voltage kunenge kaviri kunonzi kushanda Un.Kune mafirimu capacitor iyo DC-Link capacitor inogona kubatwa pasina kuwedzera kufunga.Kana electrolytic capacitors yakashandiswa, iyo over-voltage ndeye 1.2Un.Tora Shanghai metro semuenzaniso.Un=1500Vdc, ye electrolytic capacitor yekufunga nezve voltage iyi:

Ipapo iwo matanhatu 450V capacitors anofanira kubatanidzwa munhevedzano.Kana film capacitor design ikashandiswa mu600Vdc kusvika 2000Vdc kana even 3000Vdc inowanikwa zviri nyore.Mukuwedzera, simba munyaya yekubudisa zvakakwana capacitor inoumba chidimbu chechidimbu chinobuda pakati pemagetsi maviri, zvichiita kuti inrush yakawanda iripo kuburikidza neDC-Link capacitor, iyo inowanzosiyana kune electrolytic capacitors kuti isangane nezvinodiwa.

Mukuwedzera, zvichienzaniswa ne electrolytic capacitors DC-Link film capacitors inogona kugadzirwa kuti iwane yakaderera ESR (kazhinji iri pasi pe10mΩ, uye kunyange yakaderera <1mΩ) uye self-inductance LS (kazhinji iri pasi pe100nH, uye mune dzimwe nguva iri pasi pe10 kana 20nH) .Izvi zvinobvumira iyo DC-Link film capacitor kuti iiswe yakananga muIGBT module kana yaiswa, ichibvumira bhawa rebhazi kuti ribatanidzwe muDC-Link film capacitor, nokudaro kubvisa kudiwa kweiyo yakatsaurirwa IGBT absorber capacitor kana uchishandisa firimu capacitors, kuchengetedza. mugadziri mari yakawanda.Fig.2.uye 3 inoratidza hunyanzvi hwekuita zvezvimwe zveC3A neC3B zvigadzirwa.

3. Mhedziso

Mumazuva ekutanga, DC-Link capacitors ainyanya kuve electrolytic capacitors nekuda kwemitengo uye saizi kufunga.

Nekudaro, electrolytic capacitors inobatwa nevoltage uye ikozvino kushingirira kugona (yakanyanya kukwira ESR kana ichienzaniswa nemafirimu capacitors), saka zvinodikanwa kubatanidza akati wandei electrolytic capacitor munhevedzano uye parallel kuti uwane hukuru uye kusangana nezvinodiwa zvekushandisa kwemagetsi.Mukuwedzera, tichifunga nezve volatilization ye electrolyte zvinhu, inofanira kuchinjwa nguva dzose.Simba idzva rekushandisa rinowanzoda hupenyu hwechigadzirwa hwemakore gumi nemashanu, saka rinofanirwa kutsiviwa kaviri kusvika katatu panguva iyi.Naizvozvo, kune mutengo wakakura uye kusagadzikana mumashure-kutengesa sevhisi yemuchina wese.Nekuvandudzwa kwemetallization coating tekinoroji uye firimu capacitor tekinoroji, zvave zvichibvira kugadzira yakakwirira-inokwana DC sefa capacitor ine voltage kubva ku450V kusvika 1200V kana kutokwira ne Ultra-yakatetepa OPP firimu (iyo thinnest 2.7µm, kunyangwe 2.4µm) uchishandisa kuchengetedza firimu vaporization tekinoroji.Kune rumwe rutivi, kubatanidzwa kweDC-Link capacitors nebhari yebhazi kunoita kuti inverter module dhizaini iwedzere kusimba uye inoderedza zvakanyanya kurasika inductance yedunhu kuti ikwidze dunhu.