Kev piav qhia ntawm electromagnetic compatibility ntawm switching fais fab mov
Hloov fais fab mov vim kev ua hauj lwm nyob rau hauv high voltage thiab high tam sim no switching xeev, qhov ua rau ntawm electromagnetic compatibility teeb meem yog heev complex. Electromagnetism los ntawm tag nrho lub tshuab, muaj feem ntau yog impedance coupling, coupling ntawm cov kab, hluav taws xob teb coupling, magnetic teb coupling thiab electromagnetic yoj coupling ob peb yam. Common impedance coupling feem ntau yog ib qho impedance uas muaj hluav taws xob nruab nrab ntawm qhov tsis txaus siab thiab lub cev tsis zoo, los ntawm qhov teeb meem tsis txaus siab nkag mus rau hauv lub cev tsis zoo. Kab coupling feem ntau yog tsim los ntawm qhov tsis zoo ntawm qhov hluav taws xob thiab qhov cuam tshuam tam sim no ntawm cov hlau lossis PCB kab vim yog cov xaim hluav taws xob sib txuas thiab kev sib txuas. Hluav taws xob coupling feem ntau yog vim muaj qhov sib txawv ntawm qhov sib txawv, uas ua rau induced hluav taws xob teb ntawm lub cev tsis zoo uas tsim los ntawm kev sib txuas ntawm qhov chaw. Sib nqus teb coupling yog tsuas yog nyob rau hauv ib ncig ntawm lub pulsed fais fab kab ntawm high tam sim no, tiam ntawm tsawg zaus magnetic teb ntawm kev thab plaub ntawm cov khoom ntawm coupling. Electromagnetic teb coupling feem ntau yog vim lub pulsating voltage los yog tam sim no generated los ntawm high-frequency electromagnetic nthwv dej los ntawm qhov chaw mus rau sab nraud hluav taws xob, cov coj thab plaub lub cev coupling. Qhov tseeb, txhua hom kev sib txuas tsis tuaj yeem sib txawv nruj me ntsis, tsuas yog tsom mus rau qhov sib txawv.
Nyob rau hauv lub switching fais fab mov, lub ntsiab fais fab hloov raj nyob rau hauv ib tug high voltage, high-frequency switching hom, switching voltage thiab switching tam sim no nyob ze rau lub square nthwv dej, los ntawm kev tsom xam spectral, lub square yoj teeb liab muaj ib tug nplua nuj ntawm siab harmonics. . Lub spectrum ntawm lub siab sib haum xeeb tuaj yeem ua tau ntau dua 1000 npaug ntawm cov xwm txheej square yoj zaus. Nyob rau tib lub sijhawm, vim qhov xau inductance thiab kev faib tawm lub peev xwm ntawm lub zog hloov pauv nrog rau qhov tsis zoo ntawm lub xeev kev ua haujlwm ntawm lub ntsiab fais fab hloov khoom siv, cov khoom siv hluav taws xob ntau thiab high-voltage spike harmonic oscillations feem ntau tshwm sim thaum lub sij hawm high-frequency. tig-on los yog tig-off. Qhov no harmonic oscillation generates siab harmonics, uas yog kis tau mus rau hauv lub internal Circuit Court los ntawm lub tis capacitance ntawm lub switching tube thiab lub tshav kub dab dej los yog radiated rau hauv qhov chaw los ntawm lub tshav kub dab dej thiab transformer. Cov hloov diodes siv rau kev kho thiab rov ua dua tshiab kuj yog ib qho tseem ceeb ua rau muaj kev ntxhov siab ntau. Vim hais tias lub rectifier thiab rov ua dua tshiab diodes ua haujlwm nyob rau hauv high-frequency switching xeev, lub diode lead parasitic inductance, junction capacitance thiab lub xub ntiag ntawm rov qab tam sim no, thiaj li hais tias nws ua hauj lwm nyob rau hauv ib tug heev voltage thiab tam sim no tus nqi ntawm kev hloov, thiab tsim high- zaus oscillation. Rectifier thiab rov ua dua tshiab diodes feem ntau nyob ze rau ntawm cov khoom siv hluav taws xob, uas ua rau muaj kev cuam tshuam ntau zaus yuav kis tau los ntawm DC cov zis kab. Hloov cov khoom siv hluav taws xob txhawm rau txhawm rau txhim kho lub zog hluav taws xob, yog siv rau hauv kev kho lub zog hloov hluav taws xob. Nyob rau tib lub sijhawm, txhawm rau txhim kho kev ua tau zoo thiab kev ntseeg siab ntawm lub voj voog, txo qhov kev ntxhov siab ntawm cov khoom siv hluav taws xob, ntau cov khoom siv hluav taws xob hloov hluav taws xob. Ntawm lawv, xoom-voltage, xoom-tam sim no lossis xoom-voltage / xoom-tam sim no hloov tshuab yog siv dav. Cov tshuab no zoo heev txo cov hluav taws xob tsis zoo uas tsim los ntawm kev hloov khoom siv. Txawm li cas los xij, feem ntau ntawm cov khoom siv hluav taws xob tsis zoo siv hluav taws xob siv L, C rau kev hloov hluav taws xob, kev siv unidirectional conductivity ntawm lub diode kom ua tiav unidirectional hloov dua siab tshiab ntawm lub zog, yog li lub resonant Circuit Court ntawm diode tau dhau los ua qhov tseem ceeb ntawm electromagnetic nuisance nuisance. .
Hloov cov khoom siv hluav taws xob feem ntau siv lub zog cia inductors thiab capacitors los ua L, C lim circuit kom ua tiav cov lim dej ntawm hom sib txawv thiab hom kev teeb tsa tsis zoo. Vim tias qhov kev faib tawm ntawm cov inductor coil, ua rau txo qis ntawm tus kheej-resonant zaus ntawm inductor coil, yog li muaj ntau qhov kev cuam tshuam loj heev los ntawm inductor coil, raws AC fais fab kab lossis DC tso zis kab. mus rau sab nraud. Lim capacitor nrog qhov nce ntawm qhov zaus ntawm qhov teeb meem tsis txaus ntseeg, lub luag haujlwm ntawm cov hlau lead inductance ua rau muaj kev poob qis hauv capacitance thiab filtering nyhuv, thiab txawm ua rau muaj kev hloov pauv hauv capacitor tsis, kuj yog qhov ua rau muaj kev cuam tshuam ntawm electromagnetic.
