Electromagnetic Compatibility ntawm Hloov Cov Khoom Siv Hluav Taws Xob
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 cov kab PCB 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 raug cais nruj, 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 lub high-frequency switching xeev, lub hav zoov ntawm parasitic inductance ntawm cov leads ntawm lub diodes, lub hav zoov ntawm lub junction capacitance, thiab lub hwj chim ntawm lub rov qab rov qab tam sim no ua rau nws ua hauj lwm nyob rau hauv lub siab heev. voltage thiab tam sim no hloov tus nqi, thiab tsim high-frequency 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 hluav taws xob hloov pauv tsis muaj kev puas tsuaj siv hluav taws xob L thiab C los hloov lub zog, thiab siv cov 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 inductor coil, tus kheej-resonant zaus ntawm inductor coil raug txo, yog li ntawd ntau qhov kev cuam tshuam ntau zaus dhau los ntawm inductor 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 nce, lub lim capacitor lub peev xwm thiab cov nyhuv lim dej yuav txo qis tsis tu ncua vim qhov inductance ntawm cov hlau lead, thiab txawm tias ua rau muaj kev hloov pauv ntawm qhov ntsuas ntawm lub capacitor, uas yog qhov ua rau muaj kev cuam tshuam ntawm electromagnetic.
