Electromagnetic compatibility tsim ntawm switching fais fab mov
Electromagnetic compatibility (EMC) ntawm kev hloov hluav taws xob yog hais txog kev sib koom ua ke ntawm ntau yam khoom siv hluav taws xob hauv qhov chaw tsawg, lub sijhawm thiab spectrum yam tsis ua rau kev ua haujlwm tsis zoo, uas suav nrog electromagnetic cuam tshuam (EMD) thiab electromagnetic rhiab heev (EMS). EMD hais txog lub suab nrov tawm los ntawm cov khoom siv hluav taws xob, thaum EMS hais txog lub peev xwm ntawm cov khoom siv hluav taws xob los tiv thaiv hluav taws xob sab nraud. Ib qho khoom siv nrog zoo electromagnetic compatibility yuav tsum tsis txhob cuam tshuam los ntawm ib puag ncig electromagnetic ib puag ncig los yog ua rau electromagnetic cuam tshuam.
Lub hwj chim hloov raj hauv cov khoom siv hluav taws xob hloov hluav taws xob muaj qhov hluav taws xob loj thiab tam sim no dhia thaum lub sij hawm qhib-tawm ntawm cov zaus, yog li ua rau muaj zog electromagnetic cuam tshuam, tab sis qhov ntau zaus ntawm kev cuam tshuam (< 30MHz) is relatively low. The geometric size of most low-power switching power supplies is much smaller than the corresponding wavelength of 30MHz electromagnetic field (about 10m in air medium), and the electromagnetic disturbance phenomenon studied by switching power supply systems belongs to the range of quasi-stationary field. When studying their electromagnetic disturbance problems, the main consideration is conduction disturbance.
Electromagnetic cuam tshuam
Kev sib tham ntawm electromagnetic cuam tshuam feem ntau yog ua los ntawm peb yam: cov yam ntxwv ntawm kev cuam tshuam qhov chaw, cov yam ntxwv ntawm kev cuam tshuam kev sib txuas channel thiab cov yam ntxwv ntawm cov khoom cuam tshuam.
1 switching fais fab mov nyob rau hauv lub ntsiab electromagnetic cuam tshuam qhov chaw
Electromagnetic cuam tshuam qhov hauv kev hloov hluav taws xob feem ntau suav nrog cov khoom siv hloov pauv, diodes thiab cov khoom tsis sib xws; Hauv kev hloov hluav taws xob, kev xaim tsis raug ntawm cov ntawv luam tawm kuj yog qhov tseem ceeb ua rau muaj kev cuam tshuam ntawm electromagnetic.
Electromagnetic cuam tshuam los ntawm kev hloov Circuit Court
Rau kev hloov hluav taws xob, qhov cuam tshuam ntawm electromagnetic cuam tshuam los ntawm kev hloov hluav taws xob yog ib qho kev cuam tshuam loj ntawm kev hloov hluav taws xob. Switching Circuit Court yog lub hauv paus ntawm kev hloov hluav taws xob, uas yog tsim los ntawm kev hloov lub raj thiab siab zaus transformer. Lub dv/dt generated los ntawm nws yog ib tug mem tes nrog loj amplitude, dav zaus band thiab nplua nuj harmonics. Cov laj thawj tseem ceeb rau qhov kev cuam tshuam impulse no yog
1) Lub raj xa hluav taws xob hloov pauv yog thawj kauj ntawm lub tshuab hluav taws xob ntau zaus, uas yog ib qho inductive load. Thaum lub sij hawm thaum lub hloov lub raj yog qhib, lub hauv paus kauj ua ib tug zoo inrush tam sim no, thiab ib tug high surge ncov voltage tshwm nyob rau hauv ob qho tib si kawg ntawm thawj kauj. Nyob rau lub sijhawm thaum lub raj hloov pauv, ib feem ntawm lub zog tsis raug xa los ntawm thawj kauj mus rau theem nrab kauj vim yog cov dej ntws tawm ntawm thawj kauj, thiab qhov no ntawm lub zog khaws cia rau hauv inductor yuav tsim ib qho attenuation oscillation. nrog spikes nrog lub capacitors thiab resistors nyob rau hauv lub collector Circuit Court, thiab yuav superimposed ntawm lub turn-off voltage los tsim ib tug tig-off voltage spike. Qhov kev cuam tshuam ntawm lub zog hluav taws xob hluav taws xob no yuav ua rau tib lub zog hluav taws xob sib nqus tam sim no raws li thaum lub hauv paus kauj yog qhib, thiab lub suab nrov no yuav ua rau cov khoom siv hluav taws xob thiab cov khoom siv tawm, ua rau muaj kev cuam tshuam kev cuam tshuam, thiab qhov phem tshaj plaws, nws yuav tawg. lub cev hloov.
2) Lub voj voog ntau zaus hloov pauv tam sim no tsim los ntawm pulse transformer thawj kauj, hloov raj thiab lim capacitor tuaj yeem tsim hluav taws xob loj thiab tsim hluav taws xob cuam tshuam. Yog tias lub peev xwm lim dej ntawm lub capacitor tsis txaus lossis cov yam ntxwv siab zaus tsis zoo, qhov siab-frequency impedance ntawm lub capacitor yuav ua rau lub zog tam sim no mus rau AC fais fab mov hauv hom sib txawv los tsim kev cuam tshuam kev cuam tshuam.
Electromagnetic cuam tshuam los ntawm diode rectifier Circuit Court
Cov |di/dt| ntawm qhov rov qab rov qab tam sim no tsim los ntawm rectifier diode nyob rau hauv lub ntsiab Circuit Court yog ntau me dua li ntawm flywheel diode. Raws li cov khoom siv hluav taws xob cuam tshuam, qhov kev cuam tshuam ntawm qhov cuam tshuam los ntawm qhov rov qab rov qab tam sim no ntawm rectifier diode yog qhov loj thiab qhov zaus band yog dav. Qhov hluav taws xob dhia tsim los ntawm lub rectifier diode yog me dua li qhov uas tau tsim thaum lub hwj chim hloov raj hauv lub hwj huam mov yog qhib thiab tawm. Yog li ntawd, nws muaj peev xwm kawm tau lub rectifier Circuit Court raws li ib feem ntawm cov electromagnetic cuam tshuam coupling channel, tsis hais tus cawv ntawm |dv/dt| thiab |di/dt| tsim los ntawm rectifier diodes.
Kev sib raug zoo ntawm dv/dt thiab load loj
Dv / dt generated thaum lub hwj chim hloov raj yog qhib thiab tawm yog lub ntsiab cuam tshuam qhov chaw ntawm kev hloov fais fab mov. Kev soj ntsuam theoretical thiab kev sim qhia tias tus nqi ntawm |dv/dt| generated los ntawm turn-off nce nrog nce load, tab sis qhov kev hloov ntawm load muaj me ntsis cuam tshuam rau |dv/dt| tig rau. Vim yog |dv/dt| generated thaum tig rau thiab tawm yog txawv, qhov cuam tshuam pulse generated externally kuj txawv.
