Anti-interference Tsim ntawm Switching Power Supply
EMC tsim ntawm kev hloov hluav taws xob yuav tsum xav txog cov hauv qab no:
1) lim
2) High zaus transformer
3) Mos switching technology 4) Active tiv thaiv ntawm hom kev cuam tshuam
5) EMC tsim cov ntawv luam tawm hluav taws xob thaiv hluav taws xob
3 EMC Design Measures
3.1 lim
Filtering yog ib txoj hauv kev los txo cov kev cuam tshuam uas tau ua. Piv txwv li, txuas lub lim ntawm qhov kawg ntawm cov khoom siv hluav taws xob tuaj yeem cuam tshuam lub suab nrov ntawm daim phiaj hluav taws xob los ntawm kev cuam tshuam lub zog hluav taws xob nws tus kheej, thiab tuaj yeem cuam tshuam qhov cuam tshuam los ntawm kev hloov hluav taws xob thiab rov qab mus rau hauv daim phiaj hluav taws xob. Raws li ib qho tseem ceeb rau kev txwv tsis pub cuam tshuam kev cuam tshuam ntawm cov kab hluav taws xob, lub tshuab lim hluav taws xob ua lub luag haujlwm tseem ceeb hauv kev tsim hluav taws xob sib raug zoo ntawm cov khoom siv lossis cov txheej txheem. Nws tuaj yeem tsis tsuas yog txwv tsis pub cuam tshuam kev cuam tshuam ntawm cov kab sib kis, tab sis kuj tseem muaj kev cuam tshuam tseem ceeb ntawm cov hluav taws xob emission ntawm cov kab sib kis. Nyob rau hauv lub lim Circuit Court, xaiv feedthrough capacitors, peb-terminal capacitors, thiab ferrite magnetic rings tuaj yeem txhim kho cov yam ntxwv lim ntawm Circuit Court. Tsim nyog tsim los yog xaiv cov ntxaij lim dej uas tsim nyog thiab txhim kho cov ntxaij lim dej kom raug yog cov khoom tseem ceeb ntawm cov cuab yeej tiv thaiv kev cuam tshuam. Cov kev ntsuas tshwj xeeb yog raws li hauv qab no: 1) Nruab lub tshuab lim fais fab ntawm AC input davhlau ya nyob twg, thiab nws cov Circuit Court tau qhia hauv daim duab 1. Nyob rau hauv daim duab, Ld thiab Cd yog siv los tua cov suab nrov sib txawv. Feem ntau, Ld yog 100-700 μH, thiab Cd yog 1-10 μF. Lc thiab Cc yog siv los tua cov suab nrov nrov thiab tuaj yeem hloov kho raws li qhov tseeb.
Tag nrho cov lim fais fab yuav tsum tau grounded (tshwj tsis yog cov uas tsis tso cai rau hauv av raws li cov chaw tsim khoom cov lus qhia tshwj xeeb), vim hais tias hom hom bypass capacitor ntawm lub lim yuav tsum grounded ua hauj lwm. Txoj kev hauv av dav dav tsis yog tsuas yog txuas cov lim rau cov hlau casing, tab sis kuj tseem txuas cov lim casing nrog cov xov hlau tuab.
Txuas mus rau qhov chaw hauv av ntawm cov khoom siv. Qhov qis hauv av impedance, qhov zoo dua cov nyhuv lim.
Lub lim yuav tsum tau muab ntsia kom ze rau lub hwj chim inlet li sai tau. Lub tswv yim thiab tso zis kawg ntawm lub lim yuav tsum nyob deb li deb li sai tau kom tsis txhob cuam tshuam cov teeb liab los ntawm kev sib txuas ncaj qha los ntawm cov tswv yim kawg mus rau qhov kawg tso tawm.
2) Ntxiv qhov tso zis lim ntawm qhov tso zis ntawm lub hwj huam mov. Ntxiv cov capacitors ntau zaus, nce qhov inductance ntawm cov zis lim inductor thiab lub peev xwm ntawm lub lim capacitor tuaj yeem cuam tshuam cov suab nrov sib txawv. Yog tias ntau lub capacitor txuas nrog rau qhov sib npaug, cov nyhuv yuav zoo dua. 3.2 High zaus transformer
Nruab ib lub RC absorption network ntawm thawj sab, theem nrab ntawm lub siab zaus transformer, nruab nrab ntawm C thiab E ncej ntawm lub raj hloov, thiab ntawm cov zis rectifier diode.
3.3 Mos switching technology
Daim ntawv thov kev hloov pauv tshuab yuav pab txo qis kev cuam tshuam hluav taws xob, vim tias lub zog MOSFET thiab IGBT tau qhib ntawm xoom voltage thiab muab tua ntawm xoom tam sim no, thiab lub diode rov qab sai kuj yog mos, uas tuaj yeem txo cov kev siv hluav taws xob hauv lub zog. Circuit Court. Lub di / dt thiab dv / dt ntawm lub tshuab hluav taws xob tuaj yeem txo EMI qib. Nws tau raug pov thawj los ntawm kev sim uas cov tshuab hloov pauv tau yooj yim tsuas yog muaj qee yam cuam tshuam rau kev ua kom muaj kev sib haum xeeb siab ntawm lub ripple.
3.4 Active Suppression Technology ntawm Common Mode Interference
Common-mode interference active suppression technology yog ib txoj hauv kev los ntsuas los ntawm cov suab nrov los cuam tshuam cov kev cuam tshuam ntau hom. Lub tswv yim ntawm txoj kev no yog sim kom rho tawm qhov them nyiaj EMI suab nrov voltage los ntawm lub ntsiab Circuit Court uas yog tag nrho rov qab mus rau lub ntsiab hloov hluav taws xob waveform uas ua rau EMI, thiab siv nws los sib npaug ntawm qhov qub hloov voltage.
3.5 luam tawm Circuit Board
Kev xyaum tau ua pov thawj tias cov txheej txheem kev teeb tsa thiab kev tsim hluav taws xob ntawm cov ntawv luam tawm muaj kev cuam tshuam zoo rau EMC kev ua haujlwm ntawm kev hloov hluav taws xob. Kuj tseem muaj cov hluav taws xob hluav taws xob siab, nrog rau qee qhov hluav taws xob hloov hluav taws xob thiab cov khoom sib nqus. Yuav ua li cas thiaj li npaj tau txoj hauj lwm ntawm cov khoom nyob rau hauv qhov chaw txwv ntawm cov ntawv luam tawm yuav cuam tshuam ncaj qha rau kev cuam tshuam kev cuam tshuam ntawm txhua yam khoom hauv Circuit Court. thiab kev ntseeg tau ntawm Circuit Court.
3.5.1 Kev cuam tshuam ntawm hlau impedance
Los ntawm kev txheeb xyuas cov yam ntxwv impedance ntawm cov ntawv luam tawm, txoj kev tso kawm, qhov ntev, qhov dav thiab layout txoj kev ntawm cov ntawv luam tawm yog xaiv.
Cov yam ntxwv impedance ntawm ib lub xov hlau muaj DC tsis kam R thiab tus kheej inductance L
Z=R plus jωL(1) L=2lln(2)
Hauv cov mis: l - qhov ntev ntawm cov hlau;
b - kab dav.
Pom tseeb, qhov luv luv ntawm cov kab luam tawm l, qhov me me ntawm DC tsis kam R; Nyob rau tib lub sijhawm, nce qhov dav thiab tuab ntawm cov ntawv luam tawm tuaj yeem txo qhov DC tsis kam R.
Nws tuaj yeem pom los ntawm cov qauv (2) tias qhov luv luv L ntawm cov kab luam tawm, qhov me me ntawm tus kheej inductance L, thiab nce qhov dav b ntawm cov kab luam tawm kuj tuaj yeem txo tus kheej inductance L. Cov yam ntxwv impedance ntawm Ntau cov kab luam tawm tsis yog tsuas yog tsim los ntawm DC tsis kam R thiab tus kheej-inductance L, tab sis kuj muaj kev cuam tshuam ntawm kev sib nrig sib inductance M, thiab kev sib nrig sib inductance M tsis tsuas yog cuam tshuam los ntawm qhov ntev thiab dav ntawm cov kab luam ntawv, tab sis kuj muaj qhov nrug ntawm cov kab luam tawm. ua lub luag haujlwm tseem ceeb. M=2l(3)
Hauv cov qauv: s — qhov kev ncua deb ntawm ob kab, nce qhov kev ncua deb ntawm ob kab tuaj yeem txo qhov kev sib nrig sib inductance.
Raws li qhov tshwm sim saum toj no, thaum tsim lub rooj tsav xwm luam tawm, qhov impedance ntawm cov kab hluav taws xob thiab cov kab hauv av yuav tsum raug txo kom ntau li ntau tau, vim tias cov kab hluav taws xob, cov kab hauv av thiab lwm cov ntawv luam tawm muaj inductance, thaum lub hwj huam mov. tam sim no hloov tau zoo heev, nws yuav tsim ib tug loj loj voltage poob, thiab qhov voltage poob ntawm lub hauv av xaim yog ib qho tseem ceeb nyob rau hauv tsim ntawm pej xeem impedance cuam tshuam, yog li cov av xaim yuav tsum tau shortened ntau npaum li sai tau, thiab lub hwj chim hlau thiab av hlau yuav tsum tau thickened kom ntau li ntau tau.
Nyob rau hauv kev tsim ntawm ob-sided luam ntawv boards, ntxiv rau thickening lub hwj chim kab thiab hauv av kab ntau li ntau tau, ib tug decoupling capacitor nrog zoo-zaus cov yam ntxwv yuav tsum tau ntsia nruab nrab ntawm lub hauv av kab thiab lub hwj chim kab. Tsis tas li ntawd, tsis txhob khiav ob daim ntawv luam tawm kab sib luag. Yog tias tsis tuaj yeem tiv thaiv kev sib txuas txuas, nws tuaj yeem kho tau los ntawm cov hauv qab no: 1) Ntxiv cov xaim hauv av ntawm ob txoj kab teeb liab rau kev tiv thaiv;
2) Khaws qhov kev ncua deb ntawm ob lub teeb liab kab sib txuas kom deb li deb tau kom txo tau qhov cuam tshuam ntawm electromagnetic teb ntawm ob kab;
3) Cov kev taw qhia ntawm qhov tam sim no ntws los ntawm ob qho tib si teeb liab kab sib txawv. (Lub hom phiaj yog kom txo tau qhov induced magnetic flux)
3.5.2 Layout ntawm Cheebtsam
Thaum tsim ib lub rooj tsavxwm luam tawm, feem ntau yog qhov nyuaj kom tsis txhob cuam tshuam qhov chaw thiab tus neeg raug tsim txom vim qhov kev txwv ntawm kev ua haujlwm. Lub sijhawm no, sim muab cov khoom sib txuas ua ke kom tsis txhob muaj kev cuam tshuam los ntawm cov kab luam ntawv ntev dhau los vim tias cov khoom nyob deb dhau lawm; Tsis tas li ntawd, tso cov teeb liab tawm tswv yim thiab cov teeb liab tso tawm ze ntawm qhov chaw nres nkoj lead ntau li ntau tau. , kom tsis txhob cuam tshuam vim txoj kev sib txuas.
4 cov qauv ntsuas
Shielding yog ib qho tseem ceeb thiab siv tau zoo los daws cov teeb meem electromagnetic compatibility
