EMC tsim kev hloov khoom siv
Hloov cov khoom siv hluav taws xob Electromagnetic compatibility yog hais txog qhov chaw txwv, lub sijhawm thiab spectrum ntau yam, ntau yam khoom siv hluav taws xob sib koom ua ke yam tsis ua rau kev ua haujlwm tsis zoo, uas suav nrog electromagnetic harassment (EMD) thiab electromagnetic rhiab heev (EMS) ob yam ntawm cov ntsiab lus ntawm EMD hais txog. cov khoom siv hluav taws xob rau cov suab nrov sab nraud, EMS hais txog cov khoom siv hluav taws xob los tiv thaiv lub peev xwm ntawm kev ua phem rau sab nraud electromagnetic. Ib qho khoom siv nrog EMC kev ua tau zoo yuav tsum tsis txhob cuam tshuam los ntawm ib puag ncig electromagnetic ib puag ncig lossis ua rau muaj kev cuam tshuam hluav taws xob rau ib puag ncig.
Lub hwj chim hloov cov raj hauv cov khoom siv hluav taws xob hloov hluav taws xob tsim cov hluav taws xob loj thiab tam sim no dhia thaum lub sijhawm qhib / tawm ntawm cov khoom siv siab, yog li tsim hluav taws xob muaj zog, tab sis qhov ntau zaus ntawm qhov tsis txaus siab (<30MHz) is relatively low. Most of the geometry of the low-power switching power supply is much smaller than 30MHz electromagnetic field corresponding to the wavelength (about 10m in the air medium), switching power supply system to study the electromagnetic harassment phenomenon belongs to the scope of the seemingly steady field, the study of their electromagnetic harassment, the main consideration is the conduction harassment.
2 electromagnetic thab plaub
Kev sib tham ntawm electromagnetic harassment feem ntau yog los ntawm cov yam ntxwv ntawm lub hauv paus ntawm kev thab plaub, kev thab plaub ntawm cov yam ntxwv ntawm kev sib txuas thiab cov yam ntxwv ntawm lub cev cuam tshuam hauv peb yam.
2.1 Hloov cov khoom siv hluav taws xob hauv cov khoom siv hluav taws xob tseem ceeb
Hloov cov khoom siv hluav taws xob hauv cov khoom siv hluav taws xob tsis zoo yog cov khoom siv hluav taws xob hloov pauv, diodes thiab cov khoom tsis sib xws; Nyob rau hauv lub switching fais fab mov, luam Circuit Court board thaiv kuj yog ib qho tseem ceeb ua rau electromagnetic thab plaub.
2.1.1 Electromagnetic nuisance generated los ntawm lub switching circuit
Rau kev hloov pauv hluav taws xob, qhov hluav taws xob hluav taws xob ua phem tsim los ntawm kev hloov hluav taws xob yog ib qho tseem ceeb ntawm kev ua phem ntawm kev hloov hluav taws xob. Lub tshuab hluav taws xob hloov hluav taws xob yog qhov tseem ceeb ntawm cov khoom siv hluav taws xob hloov hluav taws xob, feem ntau yog tsim los ntawm kev hloov cov raj thiab cov tshuab hluav taws xob ntau zaus. Lub dv/dt generated los ntawm lub switching Circuit Court yog ib tug mem tes nrog loj irradiance, dav bandwidth thiab nplua nuj nyob rau hauv harmonics. Cov laj thawj tseem ceeb rau kev ua phem rau lub plawv no yog
1) Lub raj xa hluav taws xob hloov pauv yog thawj kauj ntawm lub tshuab hluav taws xob ntau zaus, uas yog lub zog inductive. Nyob rau hauv lub switching tube conduction lub sij hawm, tus thawj kauj ua ib tug loj inrush tam sim no, thiab nyob rau hauv thawj kauj ntawm ob kawg ntawm lub siab surge spike voltage; Nyob rau hauv lub switching tube disconnection lub sij hawm, vim lub to ntawm lub thawj kauj, uas ua rau ib feem ntawm lub zog yog tsis hloov los ntawm lub hauv paus kauj mus rau lub thib ob kauj, khaws cia nyob rau hauv lub inductance ntawm lub zog ntawm no ib feem ntawm lub zog. collector Circuit Court nyob rau hauv tsim ntawm capacitance, tsis kam nrog ib tug spike ntawm attenuation ntawm lub oscillator, superimposed ntawm lub shutdown voltage Qhov no yuav superimposed nyob rau hauv lub turn-off voltage, tsim ib tug tig-off voltage spike. Qhov kev cuam tshuam ntawm lub zog hluav taws xob no yuav ua rau tib lub magnetisation cuam tshuam tam sim no nrog lub hauv paus kauj ntawm, lub suab nrov no yuav raug xa mus rau cov tswv yim thiab cov khoom siv hluav taws xob, kev tsim cov teeb meem tshwm sim, qhov hnyav tshaj plaws ntawm lub raj hloov pauv.
2) Pulse transformer thawj kauj, switching tube thiab lim capacitors ua ib lub voj voog loj hloov tam sim no tuaj yeem tsim hluav taws xob ntau qhov chaw, tsim hluav taws xob thab plaub. Yog hais tias lub capacitor lim muaj peev xwm tsis txaus los yog cov yam ntxwv siab zaus tsis zoo, lub capacitor ntawm lub siab zaus impedance yuav ua rau lub siab zaus tam sim no nyob rau hauv daim ntawv ntawm kev sib txawv hom conduction rau AC fais fab mov los tsim ib qho teeb meem.
