Electromagnetic Compatibility Technology ntawm Switching Power Supply
Cov laj thawj rau cov teeb meem electromagnetic compatibility tshwm sim los ntawm kev hloov cov khoom siv hluav taws xob yog qhov nyuaj heev vim tias lawv ua haujlwm nyob rau hauv high-voltage thiab high-tam sim no switching tej yam kev mob. Nyob rau hauv cov nqe lus ntawm electromagnetic zog ntawm tag nrho lub tshuab, muaj feem ntau yog impedance coupling, kab-rau-kab coupling, hluav taws xob teb coupling, magnetic teb coupling thiab electromagnetic yoj coupling. Qhov sib txuas impedance feem ntau yog cov hluav taws xob feem ntau impedance ntawm qhov chaw cuam tshuam thiab lub cev cuam tshuam, los ntawm qhov teeb meem cuam tshuam nkag mus rau hauv lub cev cuam tshuam. Kab-rau-kab coupling feem ntau yog kev sib txuas ntawm cov xov hlau lossis PCB kab uas ua rau muaj kev cuam tshuam qhov hluav taws xob thiab tam sim no vim yog cov xaim hluav taws xob sib txuas. Kev sib txuas hluav taws xob feem ntau yog vim muaj qhov sib txawv ntawm qhov muaj peev xwm, uas ua rau muaj qhov sib txuas ntawm qhov hluav taws xob induced rau lub cev cuam tshuam. Sib nqus teb coupling feem ntau yog hais txog kev sib txuas ntawm qhov tsawg-frequency magnetic teb generated nyob ze ntawm high-tam sim no mem tes fais fab kab rau cov khoom cuam tshuam. Electromagnetic teb coupling yog feem ntau yog vim lub high-frequency electromagnetic tsis generated los ntawm pulsating voltage los yog tam sim no radiating tawm sab nraud los ntawm qhov chaw, thiab coupling mus rau lub cev cuam tshuam. Qhov tseeb, txhua txoj kev sib txuas tsis tuaj yeem sib txawv, tab sis qhov tseem ceeb yog txawv.
Nyob rau hauv lub switching fais fab mov, lub ntsiab fais fab hloov raj ua hauj lwm nyob rau hauv ib tug high-frequency switching hom ntawm ib tug high voltage. Lub switching voltage thiab switching tam sim no nyob ze rau square waves. Los ntawm kev tsom xam spectrum, lub teeb liab yoj square muaj cov nplua nuj kev txiav txim siab zoo. Qhov zaus spectrum ntawm lub siab sib haum xeeb tuaj yeem ncav cuag ntau dua 1000 npaug ntawm qhov square wave zaus. Nyob rau tib lub sijhawm, vim qhov xau inductance thiab faib lub peev xwm ntawm lub zog hloov pauv thiab lub xeev tsis zoo ua haujlwm ntawm lub ntsiab fais fab hloov khoom siv, cov khoom siv hluav taws xob ntau thiab cov hluav taws xob siab siab siab sib haum xeeb feem ntau tshwm sim thaum muaj ntau zaus qhib lossis kaw. . Lub siab dua harmonics generated los ntawm cov harmonic oscillation yog kis mus rau lub internal circuits los ntawm kev faib capacitance ntawm lub hloov raj thiab lub radiator los yog radiated mus rau qhov chaw los ntawm lub radiator thiab transformer. Hloov diodes siv rau rectification thiab freewheeling kuj yog ib qho tseem ceeb ua rau muaj kev cuam tshuam ntau zaus. Vim hais tias lub rectification thiab freewheeling diodes ua hauj lwm nyob rau hauv ib tug high-frequency switching xeev, lub hav zoov ntawm parasitic inductance ntawm lub diode cov hlau lead, lub hav zoov ntawm lub junction capacitance, thiab lub hwj chim ntawm lub rov qab tam sim no ua hauj lwm nyob rau hauv ib tug high voltage thiab. tam sim no tus nqi hloov pauv, thiab tsim cov zaus oscillations. Lub rectification thiab freewheeling diodes feem ntau nyob ze rau ntawm cov zis kab ntawm lub hwj chim mov, thiab cov high-frequency cuam tshuam los ntawm lawv yog feem ntau yuav kis tau los ntawm DC tso zis kab. Txhawm rau txhim kho qhov zoo ntawm lub zog, qhov hloov hluav taws xob hloov pauv hloov pauv hloov pauv hloov hluav taws xob hloov pauv hloov pauv hloov hluav taws xob hloov pauv. Nyob rau tib lub sijhawm, txhawm rau txhim kho kev ua tau zoo thiab kev ntseeg siab ntawm lub voj voog thiab txo qhov kev ntxhov siab ntawm cov khoom siv hluav taws xob, ntau cov cuab yeej siv hluav taws xob hloov pauv tau siv. Ntawm lawv, xoom voltage, xoom tam sim no lossis xoom voltage / xoom tam sim no hloov tshuab yog siv dav tshaj plaws. Cov tshuab no zoo heev txo cov electromagnetic cuam tshuam los ntawm kev hloov khoom siv. Txawm li cas los xij, feem ntau ntawm cov khoom siv hluav taws xob hloov pauv tsis muaj kev puas tsuaj siv L thiab C rau kev hloov hluav taws xob, thiab siv unidirectional conductivity ntawm diodes kom paub unidirectional zog hloov. Yog li ntawd, cov diodes nyob rau hauv lub resonant Circuit Court dhau los ua ib qho tseem ceeb ntawm electromagnetic cuam tshuam.
Hloov cov khoom siv hluav taws xob feem ntau siv lub zog cia inductors thiab capacitors los ua L thiab C lim circuits los lim cov teeb liab sib txawv thiab hom kev cuam tshuam. Vim qhov kev faib tawm ntawm cov inductance coil, tus kheej-resonant zaus ntawm inductance coil raug txo, yog li ntawd ntau qhov kev cuam tshuam ntau zaus dhau los ntawm inductance coil thiab nthuav tawm sab nraud raws AC fais fab kab lossis DC tso zis. kab. Raws li qhov zaus ntawm cov teeb liab cuam tshuam ntau ntxiv, cov nyhuv ntawm cov hlau lead inductance ntawm lub lim capacitor ua rau muaj kev poob qis hauv capacitance thiab filtering nyhuv, thiab txawm ua rau kev hloov pauv ntawm cov capacitor tsis, uas yog qhov ua rau muaj kev cuam tshuam ntawm electromagnetic cuam tshuam.
Kev daws rau Electromagnetic Compatibility
Los ntawm qhov kev xav ntawm peb lub ntsiab lus ntawm electromagnetic compatibility, los daws qhov teeb meem ntawm electromagnetic compatibility ntawm kev hloov cov khoom siv fais fab, peb tuaj yeem pib los ntawm peb yam: ua ntej, txo cov teeb liab cuam tshuam los ntawm qhov chaw cuam tshuam; thib ob, txiav tawm txoj kev nthuav tawm ntawm cov teeb liab cuam tshuam; thib peb, Txhim khu lub peev xwm tiv thaiv kev ua phem ntawm lub cev thab plaub. Thaum daws qhov sib xyaw ua ke ntawm cov khoom siv hluav taws xob hloov hluav taws xob, cov txheej txheem saum toj no tuaj yeem siv tau dav, raws li tus nqi-cov txiaj ntsig piv thiab qhov yooj yim ntawm kev siv. Yog li ntawd, cov kev cuam tshuam sab nraud tsim los ntawm kev hloov cov khoom siv hluav taws xob, xws li cov kab hluav taws xob sib haum xeeb, cov kab hluav taws xob cuam tshuam, thiab hluav taws xob hluav taws xob hluav taws xob cuam tshuam, tsuas yog daws tau los ntawm kev txo qhov cuam tshuam. Ntawm qhov tod tes, nws tuaj yeem txhim kho tus qauv tsim ntawm lub tswv yim / tso zis lim Circuit Court, txhim kho kev ua haujlwm ntawm APFC Circuit Court, txo qhov voltage thiab tam sim no hloov tus nqi ntawm lub raj hloov, rectifier thiab freewheeling diode, thiab txais yuav ntau yam mos switching circuit topologies. thiab tswj txoj kev, thiab lwm yam; Lwm qhov ntawm ib sab, ntxiv dag zog rau kev tiv thaiv kev tiv thaiv ntawm lub casing, txhim kho qhov sib txawv ntawm lub casing, thiab ua haujlwm zoo hauv av. Rau kev muaj peev xwm tiv thaiv kev cuam tshuam sab nraud (xws li surges thiab xob laim tawm tsam), lub peev xwm tiv thaiv xob laim ntawm AC input thiab DC output ports yuav tsum tau ua kom zoo dua. Feem ntau, rau qhov sib xyaw ua ke ntawm xob laim tawm tsam ntawm 1.2 / 50μs qhib-circuit voltage thiab 8/20μs luv-circuit tam sim no, vim lub zog me me, feem ntau yog daws los ntawm kev sib txuas zinc oxide varistors thiab roj square hluav taws xob raj. Rau electrostatic paug, feem ntau yog nyob rau hauv lub me me teeb liab Circuit Court ntawm qhov chaw nres nkoj kev sib txuas lus thiab kev tswj chaw nres nkoj, siv TVS raj thiab coj grounding tiv thaiv, ua rau kom cov hluav taws xob nyob deb ntawm lub me me teeb liab Circuit Court thiab lub chassis, thiab lwm yam. static cuam tshuam. Lub teeb liab ceev ceev muaj qhov dav dav spectrum, thiab nws yog ib qho yooj yim kom dhau mus rau hauv kev tswj Circuit Court nyob rau hauv daim ntawv ntawm ntau hom. Tib txoj hauv kev los tiv thaiv zoo li qub yog siv los txo qhov kev faib tawm ntawm cov hom hom inductance thiab ntxiv dag zog rau cov hom teeb liab lim ntawm cov khoom siv hluav taws xob (ntxiv rau Hom Hom capacitors lossis qhov ntxig poob ferrite cores, thiab lwm yam) txhawm rau txhim kho kev tiv thaiv kab mob. ntawm qhov system.
Txhawm rau txo qhov cuam tshuam sab hauv ntawm lub zog hloov hluav taws xob, paub txog nws tus kheej electromagnetic compatibility, thiab txhim kho kev ruaj ntseg thiab kev ntseeg siab ntawm kev hloov hluav taws xob, cov hauv qab no yuav tsum tau pib:
① Ua tib zoo saib xyuas qhov raug faib ntawm digital circuit thiab module Circuit Court PCB thaiv;
②Decoupling ntawm digital circuit thiab analog circuit fais fab mov;
③ Ib qho taw qhia hauv av ntawm digital circuits thiab analog circuits, ib qho taw qhia grounding ntawm high-tam sim no circuits thiab low-tam sim no circuits, tshwj xeeb tshaj yog tam sim no thiab voltage sampling circuits, kom tsis txhob muaj kev cuam tshuam kev cuam tshuam thiab kev cuam tshuam ntawm av rings. Thaum xaim, xyuam xim rau qhov sib txawv ntawm cov kab uas nyob ib sab thiab cov khoom siv hluav taws xob, tsis txhob sib tham, txo qhov chaw nyob ib puag ncig los ntawm cov khoom siv hluav taws xob rectifier, lub freewheeling diode Circuit Court thiab ceg lim Circuit Court, txo cov xau ntawm lub transformer, qhov kev faib tawm ntawm cov khoom siv hluav taws xob. lim inductor, thiab siv lim capacitors nrog siab resonance zaus.
