Muri iki cyumweru turakomeza n'inkuru y'icyumweru gishize.

1.2 Capacitors za Electrolytic

Dielectric ikoreshwa muri capacitors za electrolytic ni aluminium oxyde ikorwa na corruption ya aluminium, ifite dielectric constant ya 8 kugeza 8.5 n'imbaraga za dielectric zakora za 0.07V/A (1µm=10000A). Ariko, ntibishoboka kugera kuri ubwo bunini. Ubunini bw'urwego rwa aluminiyumu bugabanya ubushobozi (capacitance yihariye) bwa capacitors za electrolytic kuko foil ya aluminiyumu igomba gucibwa kugira ngo hakorwe filime ya aluminium oxyde kugira ngo haboneke imiterere myiza yo kubika ingufu, kandi ubuso buzakora ubuso bwinshi butangana. Ku rundi ruhande, resistivity ya electrolyte ni 150Ωcm kuri voltage nke na 5kΩcm kuri voltage nyinshi (500V). Resistivity yo hejuru ya electrolyte igabanya RMS current capacitor ya electrolytic ishobora kwihanganira, akenshi ikaba 20mA/µF.

Kubera izi mpamvu, capacitors za electrolytic zagenewe voltage ntarengwa ya 450V isanzwe (bamwe mu bakora ku giti cyabo bashushanya 600V). Kubwibyo, kugira ngo ubone voltage nyinshi ni ngombwa kuzigeraho uhuza capacitors mu buryo bukurikiranye. Ariko, kubera itandukaniro mu bushyuhe bwa buri capacitors za electrolytic, resistor igomba guhuzwa na buri capacitors kugira ngo ihuze voltage ya buri capacitors ihujwe. Byongeye kandi, capacitors za electrolytic ni ibikoresho bya polarized, kandi iyo voltage ikoreshwa inyuma irenze inshuro 1.5 za Un, habaho reaction ya electrochemique. Iyo voltage ikoreshwa inyuma ihagije, capacitors zirasuka. Kugira ngo hirindwe iki kibazo, diode igomba guhuzwa iruhande rwa buri capacitors iyo ikoreshejwe. Byongeye kandi, ubushyuhe bwa voltage bwa capacitors za electrolytic muri rusange ni inshuro 1.15 za Un, kandi nziza zishobora kugera kuri Un inshuro 1.2. Bityo rero, abashushanya ntibagomba gutekereza gusa ku muvuduko uhoraho w'amashanyarazi ahubwo no ku muvuduko wa surge mugihe bazikoresha. Muri make, imbonerahamwe ikurikira yo kugereranya hagati ya capacitors za filime na capacitors za electrolytic irashobora gushushanywa, reba Ishusho ya 1.

2. Isesengura ry'Ikoreshwa

Capacitors za DC-Link nk'amafiriti zikenera imiterere y'amashanyarazi menshi n'ubushobozi bwinshi. Urugero ni sisitemu nyamukuru y'imodoka nshya ikoresha ingufu nk'uko bivugwa ku Ishusho ya 3. Muri ubu buryo, capacitors zigira uruhare mu gukuraho ingufu kandi urusobe rw'amashanyarazi rufite imbaraga nyinshi. Capacitors za DC-Link zifite akarusho ko kwihanganira ingufu nini zikoreshwa (Irms). Fata urugero rw'ibipimo by'imodoka nshya ifite ingufu zingana na 50~60kW, ibipimo ni ibi bikurikira: voltage y'imikorere 330 Vdc, voltage ya ripple 10Vrms, voltage ya ripple 150Arms@10KHz.

Hanyuma ubushobozi buke bw'amashanyarazi bubarwa muri ubu buryo:

Ibi biroroshye kubishyira mu bikorwa mu gushushanya capacitor ya firime. Dufashe ko hakoreshwa capacitor za electrolytic, niba harebwe 20mA/μF, ubushobozi buke bwa capacitor za electrolytic bubarwa kugira ngo buhuze n'ibipimo byavuzwe haruguru ku buryo bukurikira:

Ibi bisaba capacitors nyinshi za electrolytic zifatanye kugira ngo ubone ubwo bushobozi.

Mu bikorwa bya volteji nyinshi, nka gari ya moshi yoroheje, bisi zikoresha amashanyarazi, gari ya moshi yo munsi y'ubutaka, nibindi. Ukurikije ko izi ngufu zihujwe na pantografi ya gari ya moshi binyuze muri pantografi, aho pantografi na pantografi bihurira mu gihe cy'urugendo rwo gutwara abantu. Iyo byombi bitahuye, amashanyarazi ashyigikirwa na capacitor ya wino ya DC-L, kandi iyo contact igarutse, volteji nyinshi irakorwa. Ikibazo kibi cyane ni uko capacitor ya DC-Link isohoka burundu iyo ivanyweho, aho voltage yo gusohora ingana na voltage ya pantografi, kandi iyo contact igarutse, volteji nyinshi ivamo iba ikubye hafi kabiri ugereranyije na Un. Kuri capacitors za filime capacitor ya DC-Link ishobora gufatwa nta kindi cyifuzo cyiyongereyeho. Iyo hakoreshejwe capacitors za electrolytic, volteji nyinshi ni 1.2Un. Fata urugero rwa metro ya Shanghai. Un = 1500Vdc, kuri capacitor ya electrolytic urebye voltage ni:

Hanyuma capacitors esheshatu za 450V zigomba guhuzwa mu buryo bukurikiranye. Iyo igishushanyo mbonera cya capacitor cya filime gikoreshejwe muri 600Vdc kugeza kuri 2000Vdc cyangwa 3000Vdc biroroshye kugeraho. Byongeye kandi, ingufu iyo capacitor isohoye neza ikora umuyoboro mugufi hagati ya electrodes zombi, bigatuma umuyoboro munini w’amashanyarazi unyura muri capacitor ya DC-Link uba utandukanye kugira ngo capacitors zihuze n’ibikenewe.

Byongeye kandi, ugereranije na capacitors za electrolytic, capacitors za filime za DC-Link zishobora gukorwa kugira ngo zigere kuri ESR nke cyane (ubusanzwe iri munsi ya 10mΩ, ndetse no hasi ya <1mΩ) na LS yigenga (ubusanzwe iri munsi ya 100nH, ndetse rimwe na rimwe iri munsi ya 10 cyangwa 20nH). Ibi bituma capacitors za filime za DC-Link zishyirwa muri module ya IGBT iyo zikoreshejwe, bigatuma bisi ishyirwa muri capacitors za filime za DC-Link, bityo bikavanaho gukenera capacitors za IGBT zifata umwanya wabugenewe mu gihe ukoresha capacitors za filime, bigatuma uwashushanyije atakaza amafaranga menshi. Ishusho ya 2 na 3 igaragaza ibisobanuro bya tekiniki bya bimwe mu bicuruzwa bya C3A na C3B.

3. Umwanzuro

Mu minsi ya mbere, capacitors za DC-Link zari zigizwe ahanini na capacitors za electrolytic bitewe n'ibiciro n'ingano.

Ariko, capacitors za electrolytic zigirwaho ingaruka n'ubushobozi bwo kwihanganira voltage n'amashanyarazi (ESR iri hejuru cyane ugereranije na capacitors za filime), bityo ni ngombwa guhuza capacitors nyinshi za electrolytic zikurikirana kandi zigahuza kugira ngo zibone ubushobozi bwinshi kandi zihuze n'ibisabwa mu ikoreshwa rya voltage nyinshi. Byongeye kandi, ukurikije ihindagurika ry'ibikoresho bya electrolyte, bigomba gusimburwa buri gihe. Ingufu nshya muri rusange zisaba igihe cy'imyaka 15, bityo zigomba gusimburwa inshuro 2 kugeza kuri 3 muri iki gihe. Kubwibyo, hari ikiguzi kinini n'ingorane muri serivisi nyuma yo kugurisha y'imashini yose. Hamwe n'iterambere ry'ikoranabuhanga ryo gusiga irangi ry'icyuma n'ikoranabuhanga rya capacitors za filime, byashobotse gukora capacitors za DC zifite ubushobozi bwinshi zifite voltage kuva kuri 450V kugeza 1200V cyangwa zirenzeho hakoreshejwe filime ya OPP yoroshye cyane (2.7µm, ndetse na 2.4µm) hakoreshejwe ikoranabuhanga ryo gusesagura firime. Ku rundi ruhande, guhuza capacitors za DC-Link na bus bar bituma imiterere ya module ya inverter iba nto kandi bigabanya cyane uburyo inductance ya circuit igenda ihinduka kugira ngo circuit irusheho kuba nziza.