Electromagnetic compatibility teeb meem ntawm switching fais fab mov
Vim hais tias kev sib txuas lus hloov cov khoom siv hluav taws xob ua haujlwm nyob rau hauv lub xeev hloov ntawm high voltage thiab tam sim no loj, electromagnetic compatibility teeb meem tshwm sim los ntawm nws yog heev complex. Nyob rau hauv cov nqe lus ntawm electromagnetic compatibility ntawm tag nrho cov tshuab, muaj feem ntau yog impedance coupling, kab-rau-kab coupling, hluav taws xob teb coupling, magnetic teb coupling thiab electromagnetic yoj coupling. Peb lub ntsiab lus ntawm electromagnetic compatibility yog: cuam tshuam qhov chaw, propagation path thiab interfered khoom. Common impedance coupling feem ntau txhais tau hais tias qhov cuam tshuam los ntawm qhov cuam tshuam thiab cov khoom cuam tshuam muaj ib qho hluav taws xob impedance, thiab cov teeb liab cuam tshuam nkag mus rau cov khoom cuam tshuam los ntawm qhov impedance no. Kab-rau-kab coupling feem ntau yog kev sib txuas ntawm cov xov hlau lossis cov kab PCB uas tsim cov kev cuam tshuam voltages thiab cuam tshuam tam sim no vim yog cov xaim sib txuas. Kev sib txuas hluav taws xob feem ntau yog vim muaj qhov sib txawv ntawm qhov sib txawv thiab qhov sib txuas ntawm qhov hluav taws xob cuam tshuam rau cov khoom cuam tshuam. Sib nqus teb coupling feem ntau yog cov coupling ntawm tsawg zaus magnetic teb generated nyob ze ntawm high-tam sim no mem tes fais fab kab mus cuam tshuam cov khoom. Electromagnetic yoj coupling feem ntau yog los ntawm high-frequency electromagnetic waves generated los ntawm pulsating voltage los yog tam sim no, uas tawm sab nraud los ntawm qhov chaw thiab ua rau coupling mus rau lub cev cuam tshuam. Qhov tseeb, txhua txoj kev sib txuas tsis tuaj yeem raug cais nruj me ntsis, tab sis lub hom phiaj sib txawv.
Nyob rau hauv lub switching fais fab mov, lub ntsiab fais fab hloov 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 yog ob qho tib si square waves. Lub spectrum ntawm qhov kev txiav txim siab sib haum xeeb uas muaj nyob rau hauv lub xwmfab nthwv dej tuaj yeem ncav cuag lub xwmfab yoj zaus. ntawm ntau dua 1, 000 zaug. Nyob rau tib lub sijhawm, vim qhov xau inductance thiab faib lub peev xwm ntawm lub zog hloov hluav taws xob, nrog rau kev ua haujlwm tsis zoo ntawm lub tshuab hluav taws xob hloov hluav taws xob tseem ceeb, cov khoom siv hluav taws xob ntau thiab high-voltage peak harmonic oscillations feem ntau tshwm sim thaum hloov los yog tawm ntawm high zaus. Qhov no harmonic oscillation generates high-order Harmonics yog nkag mus rau hauv lub internal Circuit Court 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 rectifier thiab freewheeling diodes ua hauj lwm nyob rau hauv ib tug high-frequency switching xeev, vim lub hav zoov ntawm lub diode tus lead parasitic inductance, junction capacitance, thiab lub zog ntawm lub rov qab tam sim no, lawv ua hauj lwm nyob rau hauv lub high voltage thiab tam sim no hloov pauv tus nqi, ua rau. nyob rau hauv high-frequency oscillation. Vim hais tias cov rectifier thiab freewheeling diodes feem ntau yog nyob ze rau ntawm lub hwj chim tso zis kab, lub high-frequency cuam tshuam lawv tsim yog feem ntau yuav kis tau los ntawm DC tso zis kab.
Txhawm rau txhim kho cov khoom siv hluav taws xob zoo, kev sib txuas lus hloov hluav taws xob siv hluav taws xob siv hluav taws xob hloov kho hluav taws xob hloov hluav taws xob. Nyob rau tib lub sijhawm, txhawm rau txhim kho kev ua tau zoo thiab kev ntseeg siab ntawm cov circuits thiab txo cov hluav taws xob kev ntxhov siab ntawm cov khoom siv hluav taws xob, cov khoom siv hluav taws xob hloov pauv tau dav 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, cov hluav taws xob hloov hluav taws xob tsis zoo feem ntau siv l thiab c rau kev hloov hluav taws xob, thiab siv cov khoom siv hluav taws xob unidirectional ntawm diodes kom ua tiav unidirectional zog hloov. Yog li ntawd, cov diodes nyob rau hauv lub resonant Circuit Court tau dhau los ua ib qho tseem ceeb ntawm electromagnetic cuam tshuam.
Hauv kev sib txuas lus hloov cov khoom siv hluav taws xob, lub zog cia inductors thiab capacitors feem ntau yog siv los tsim l thiab c lim circuits los lim cov hom sib txawv thiab hom kev cuam tshuam cov teeb liab thiab hloov AC square wave signals rau hauv DC teeb liab. Vim qhov kev faib tawm ntawm cov inductor coil, tus kheej-resonant zaus ntawm inductor coil raug txo, ua rau muaj ntau qhov kev cuam tshuam ntau zaus dhau los ntawm inductor coil thiab nthuav tawm sab nraud raws li AC fais fab kab lossis DC tso tawm kab. . Raws li qhov zaus ntawm cov teeb liab cuam tshuam nce, lub peev xwm thiab kev lim dej ntawm lub lim capacitor txuas ntxiv txo qis vim qhov cuam tshuam ntawm cov hlau lead inductance. Txog thaum nws nce mus txog saum lub resonant zaus, nws poob tag nrho nws txoj haujlwm raws li lub capacitor thiab ua inductive. Kev siv tsis raug ntawm cov lim capacitors thiab cov txhuas ntev ntev kuj ua rau muaj kev cuam tshuam electromagnetic.
