Chinoshandura data chako chinoshanda zvakanaka pabhenji. Zvadaro chinosvika kuEMC lab, uye scan yacho inokundikana. Kana kuti zvakatoipa, chinotumirwa uye chinovhara waya iri pedyo.
Haugone kuona kupindirana kwemagetsi sebhokisi rekupedzisira. Mukushandura kweac-dc, kudzvinyirirwa kweEMI kunodzivirira zvinhu zvitatu panguva imwe chete: kutevedzera mitemo, kuchengetedzeka kwechigadzirwa, uye kuvimbika kwenguva refu kwesystem. Kukundikana kwekushanda kwemagetsi kunoitikawo kunonoka, apo dhizaini itsva inodhura zvakanyanya.
Tanga nefizikisi. Tsvaga kwakabva ruzha, tevera nzira yekubatanidza, wobva wasarudza sefa. Gwaro iri ndere mainjiniya ehardware nemapoka ezvigadzirwa vanoenzanisa dhizaini yepamusoro-soro nekuchinjana kwezvigadzirwa zuva nezuva.
Zvitsva Zvitsva
Tsvaga kwakabva ruzha uye nzira yekubatanidza ruzha kutanga. Wobva wasarudza sefa chaiyo.
Ruzha rwemhando dzakasiyana runoda LC filter. Ruzha rwemhando dzakajairika runoda choke uye Y capacitor.
Isa mafirita ekuisa panzvimbo inosanganisirwa. Chengeta Y capacitor ichidzokera padyo nechassis.
Nyorovesa nhanho yega yega yeLC kudzivirira kurira uye kuchengetedza input yakagadzikana.
Ita bvunzo dzekutanga usati watevedzera mitemo yemuviri kuti ubate utsi hwemhepo usati waenda kukiriniki.
Manyuko Eruzha Mukushandurwa kweAC-DC
Kuchinjana Kwekushanda Zvakanaka
Danho rega rega rekushandura ac-dc rinoita shanduko pakati pekushanda zvakanaka neruzha. Unosimudza frequency yekuchinja kuti transformer ive diki wobva waderedza kurasikirwa kwepakati. Asi mupendero iwoyo unokurumidza unogadzira shanduko dzemagetsi dzakasimba uye shanduko dzemagetsi. Mupendero unokurumidza unoreva dv/dt yakakwira uye di/dt, uye shanduko idzodzo dzinopa zvese zvinoburitswa nemagetsi anobuda.
Unotarisana nekunetsana chaiko pano. Kuchinja kwakakwira kunovandudza huwandu hwesimba mumagetsi eswitch-mode, asi kunosundira simba reharmonic muma frequency bands uko firita yako isingashande zvakanaka. Mipendero inononoka inonyorovesa emi spectrum, asi inopisa simba rakawanda muswitch. Unofanira kuona izvi sedhizaini inoshanduka , kwete seyakagadziriswa. Sarudza switching frequency ne gate drive pamwe chete, wobva watarisa spectrum inobuda nekukurumidza.
Kuverenga Ruzha neFourier Analysis
Chimiro che "switching waveform" chinofamba nemhepo nguva nenguva. Kuongororwa kweFourier kunopatsanura chitima ichocho kuita "fundamental" uye "harmonics" dzacho. Ma "harmonic amplitudes" anodonha zvichienderana ne "frequency", uye "envelopu slope" inoenderana nenguva yekukwira nekudonha. Unogona kushandisa izvi kufanotaura kuti mhepo yakasviba zvakanyanya ichawira kupi usati wagadzira bhodhi.
Mafambiro eNotch mu spectrum anobva kuFourier transform ye pulse-coded signal. Imwe ongororo yakaongorora ma notch equations aya e pulse train chete, kwete full converter. Mafambiro e notch akayerwa uye akayerwa akaenzana zvakanyanya nema derived equations, uye vanyori vakasiya full-converter derivation yebasa remangwana.
Kutorwa kwenotch frequency kunoonekwa, uko ma equation akawanikwa anoenderana neFourier transform yema pulse-coded signals pane system ye converter yakazara. Ma moderation e notch akaenzaniswa uye e experimental anoenderana zvakanyanya ne derivative theoretical equation, nepo derivation ye converter yakazara ichizoendeswa kubasa remangwana.
Shandisa mhinduro iyi nokungwarira. Modhi yepulse-train inokupa fungidziro yekutanga inobatsira pakuronga kuderedza ruzha mumaconverter eac/dc. Haibate resonance yese mumapower supplies e switched-mode, saka simbisa fungidziro yacho pabhenji.
Maitiro Makuru Ekubatanidza EMI
Ruzha runoda nzira kuti ruve dambudziko. Unogona kupatsanura nzira huru dzekubatanidza dze-emi kuita mhuri mbiri. Mhuri yega yega inoita nenzira yayo, uye imwe neimwe inoda kugadziriswa kwakasiyana.
Nzira Dzinofambisa uye Dzinopenya
Kubatanidza kunofambisa mhepo kunoda kubatana zvakananga. Chitubu nereceptor zvinogovana waya, tambo, PCB trace , kana simbi yakavharirwa. Ruzha runobva rwafamba neconductor iyoyo se common-mode kana differential-mode current. Kubatanidza kunopa chiedza kunoshanda neimwe nzira. Chitubu nereceptor zvinoshanda sema antenna eredhiyo. Chitubu chinotumira wave ye electromagnetic kuburikidza nenzvimbo yakavhurika, uye munhu anobatwa anoitora.
Nzira yekubatanidza | Mechanism | Unhu Hwakakosha |
|---|---|---|
Kuita | Nzira yekubatana zvakananga pakati pechinhu chinobuda nechinhu chinogamuchira | Yakagadzirwa kuburikidza netambo yekutumira, waya, tambo, PCB trace, kana simbi yakavharirwa; ruzha runoonekwa se common-mode kana differential-mode pama conductors |
Yakapiswa nemwaranzi | Chitubu nechinhu chinogamuchira zvinoshanda semaantenna eredhiyo | Chitubu chinoburitsa mafungu emagetsi anopararira munzvimbo yakashama uye anotorwa nemunhu anenge abatwa. |
Kubatanidza kweinductive, zvese capacitive nemagnetic, kuripowo. Kuone sekusingawanzoitiki padyo nenzira dzinofambisa mhepo nedzakasvibira. Paunogadzirisa bhodhi rakakundikana, tarisa radiation, conduction, kana inductive kana capacitive coupling nenzira iyoyo. Zviviri zvekutanga zvinotsanangura kukundikana kwakawanda.
Nei Maumbirwo Emarongerwo Akabatana
Kurongeka kunosarudza kuti nzira yega yega yekubatanidza maemi inosimba zvakadii. Seminari yehunyanzvi yakashandisa converter chaiyo yeDC/DC yakayerwa kuratidza izvi. Magadzirirwo akasiyana ePCB akachinja siginecha yeEMI yemushanduri zvakananga. Kuiswa kwezvikamu zvisingashande uye kusarudzwa kwakachinjawo mashandiro eEMC. Seminari imwecheteyo yakaratidza nzira dzekusefa kuti dzisvike pamiganhu yeCISPR32 Class B kubva pa150 kHz kusvika ku1 GHz. Iyo range inoratidza kuti coupling inotungamirwa nehurongwa inofanira kutarisirwa pamwe chete nekusefa.
Kuswedera pedyo kwechikamu kunokosha mukati mefirita pachayo:
Kubatana kwemagineti pedyo nemunda pakati pePFC neCM chokes kunogona kuderedza kurasikirwa kwekuisa kweEMI filter.
Kurongeka, kudzivirira, uye dhizaini yeCM choke zvinoderedza kubatana kwemagnetic near-field uye zvinoderedza ruzha.
Kubatana pakati pema capacitor maviri e shunt kunochinja maitiro e filter; negative mutual coupling inogona kudzikamisa capacitor ESL.
Mufirita yeCLC, kuyera kubatana kweparasitic inductive ne capacitive pakati pema capacitors kunoita kuti mashandiro abudirire.
Mufirita ine matanho maviri, nzira yekubatanidza inductor inotevedzana inoshandisa kubatana kwepedyo nemunda kuvandudza mashandiro eDM asingawanzoitiki.
Kurongeka kwakanaka kunoderedza kusvibiswa kwemhepo usati waisa chero chikamu chefirita. Gadzirisa jiometri kutanga, wobva wagadzirisa firita.
Nzira Yokusiyanisa vs. Ruzha Rwemodhi Yakajairika
Kutsanangura Ruzha rweDM neCM
Haugone kugadzirisa ruzha kusvika waziva kuti ndeipi nzira inorutakura. Nzira mbiri idzi dzinosiyana munzira, nzira, uye nzira yekurapa.
Common mode zvinoreva masaini kana ruzha runoyerera nenzira imwechete mumitsetse miviri; differential (normal) mode zvinoreva masaini kana ruzha runoyerera nenzira dzakasiyana mumitsetse miviri.
Ruzha rwemhando dzakasiyana runobuda pa kondakita imwe chete uye runodzoka panzira yarwo yekudzoka. Ruzha rwemhando dzakajairika runoyerera nenzira imwechete pamitsetse yese miviri uye runodzoka nepasi kana chassis. Musiyano iwoyo unosarudza kuti ndeipi firita yaunosarudza.
Kuonekwa | Ruzha rweModhi Yekusiyanisa | Common Mode Noise |
|---|---|---|
tsananguro | Ruzha rwunotumirwa kuburikidza nemakondirakita maviri, imwe nzira yekubuda uye imwe nzira yekudzokera | Ruzha rwemagetsi runopinda zvisinei nenzira dzinobuda/dzokudzoka uye runoyerera nenzira imwe chete kuburikidza nemakonductor maviri |
Nhungamiro yazvino | Nzira dzakapesana (mafungu anodzima mumwe nemumwe); inonziwo normal mode | Nzira imwe chete kuburikidza nevanotungamira vese |
Kupararira | Inogara mukati memutsara wesimba/chiratidzo | Inopararira munzvimbo yakakura, kunyange zvazvo iri padanho remagetsi rakaderera |
Kwakatangira zvinhu zvakajairika | Simba remagetsi uye masaini emagetsi | Ruzha runodonhedza simbi kana pasi ruchipinda mune zvimwe zvishandiso |
Kudzvinyirira | Yakachekwa nemafirita eLC (inductor + capacitor) | Mafirita eLC haashande; anoda firita yemode yakafanana pamwe ne capacitor pachikamu chekupinda |
Sefa yeLC chete haimise common mode emi . Unoda common mode choke pamwe ne capacitor pakupinda.
Kuyera Ruzha neLISN
Network yekusimbisa mutsetse inokupa referensi yakagadzikana yekuyera ruzha rweac/dc converter. Inoratidza set impedance kune converter uye inoparadzanisa mains. Network inoburitsa mavoltage maviri, rimwe riri pamutsetse wephase (Vp) uye rimwe riri pamutsetse we neutral (Vn). Izvi zvine chekuita nemode currents neVp = 50(ICM + IDM) uye Vn = 50(ICM − IDM), ne50 mu ohms. Wedzera ma outputs maviri uye differential term cancels, zvichisiya kaviri common mode voltage. Bvisa iwo uye common mode term cancels, zvichisiya kaviri differential mode voltage. Ita izvi usati wayera, nekuti analyzer inorasikirwa neruzivo rwephase.
Kutevedzana kunoshanda kunobatsira:
Rangarira kuti LISN inoyera huwandu hwemamodhi ese ari maviri uye haigone kuaparadzanisa ari ega.
Batanidza probe yeRF current yakatenderedza mutsetse uye neutral pamwe chete kuti uverenge common mode current.
Dzorera waya mbiri munzira dzakasiyana kuburikidza neprobe kuti uverenge differential mode current; kuverenga kwacho kuri 6 dB yakakwira.
Ramba uri pasi pehuwandu hwepamusoro hweprobe.
Enzanisa kuverenga kwese kuti uone kuti ndeipi nzira inonyanya kukosha , wobva waisa saizi mufirita.
Danho iri rinokuudza kana woisa DM inductance kana X-capacitors. Rinoratidzawo kana ma emissions anoitwa anobva munzira ye common mode.
Kusarudza EMI Filters dzeDC/DC Inputs
Paunosarudza mafirita emi ekushandisa DC/DC input, tanga wabvunza kuti unoda frequency yekona ipi. Isa kona yeLC kune chikamu chimwe mugumi che switching frequency. 1 MHz converter inobva yada kona ye100 kHz. Nemukana iwoyo, firita ye second-order low-pass emi yakanaka inopa angangoita 40 dB yekudzikamisa pa fundamental. Mabhodhi chaiwo anopa zvishoma, kazhinji anenge 30 dB, nekuti capacitor ESL ne trace inductance zvinoderedza curve.
Parameter | chipfuro | Chinyorwa Chinoshanda |
|---|---|---|
Kucheka-kureka kuwanda | Inenge 1/10 yefrequency yekuchinja | Kuderedza kwakanyanya kwesimba remagetsi kunosvika 40 dB padanho rekutanga |
Kureruka kwekudzikira kwemvura | 40 dB/gumi remakore yakakodzera | Zvipembenene zvinoderedza kukwira kwechokwadi |
Kukosha kweInductor | 0.47 µH kusvika 22 µH | Kudzikira kweinductance kunocheka DCR nehukuru |
1 µF kusvika 100 µF | Tarisa chiyero chemagetsi uye kudonha kwetembiricha | |
Kuderedza Q | 0.5 kuna 0.8 | Wedzera capacitor inonyungudutsa ine 3–4× ye capacitor yekupinda |
LC Filter Basics uye Voltage Drop
Danho rimwe chete reLC low-pass ndiro sarudzo iri nyore. π-filter kana network ine matanho akawanda inokodzera miganhu yakaoma kana source impedance inochinja-chinja zvakanyanya. Matanho akawanda e capacitor anovandudza high-frequency attenuation, asi anokwidza inrush current uye anochinja damping. Tarisa kugadzikana zvakare mushure mekuwedzera danho rega rega.
Tarisa kudonha kwemagetsi eDC pa inductor. DCR inodya headroom, uye chikamu chakayerwa che peak current chinogona kuramba chakazara kana paine hot-plug. Saizi ye inductor kuti ione peak current, kwete average current. Chengetedza high di/dt loop pfupi: isa inductor pedyo nemapini ekupinda e converter wodzorera current panzira yakamanikana.
Kuderedza Kugadzikana uye Kuderedza CM
Mhete dzefirita dzisina kuvharwa. Kuvharwa kwemhepo kwefirita kunofanira kugara pasi peimpedance yekupinda ye converter mu bandwidth ye control-loop. Iyi ndiyo nzira yaMiddlebrook, uye kuregeredza kunokonzera kudonha kwemagetsi kwakadzika, kubhururuka kwenguva refu, uye kutenderera kwekupinda. Unogona kutarisa nekusarudza mafirita e-emi nemutemo uyu usati wabata simbi inosonerera.
Pane sarudzo dzakasiyana-siyana dzekudzikisa mvura:
Zvinhu zvemagineti zvinorasikirwa zvakanyanya (Micrometals Mix-41, 44, uye 73) zvinonyorova sefa zvichipfuura nepakati pesimba remagetsi.
Maseketi eDamper anochengetedza peak pa cut-off frequency iri pasi pe2–3 dB, izvo zvinomisa kuwedzera kweruzha mumiedzo yakaita seMIL-STD-461F/G CS101.
Kusateerera kweRC uye kudzikamisa simba muma filter capacitors kunoita kuti mhinduro irambe yakasimba.
Kudzima damping inoshanda ndeimwe sarudzo kana zvikamu zvisingashande zvichidhura nzvimbo yakawanda yebhodhi.
Shandisa frequency response analysis kuti utarise damping, kwete time-domain testing chete. Kuchinjana kumwe chete kunoda kutariswa: kuwedzera feedback loop gain kunovandudza kuderedzwa kweruzha uye kusefa emi, asi kunogona kuderedza phase margin kunze kwekunge wabhadhara zvakanaka. Kune common mode, wedzera choke uye Y capacitor pakupinda; LC stage yega haizoimise. Mhando idzi dzeemi filters dzinoshanda pamwe chete, uye musanganiswa wakakodzera unochengetedza emissions dziri pasi pemuganhu.
Dhizaini yeAC/DC Front-End yeLow EMI
Kugadziriswa, Zvigadziriso Zvikuru, uye Kuderedza Kupinda Kwemvura
Kumberi kwemagetsi ndiko kunogadzira ruzha rwezvinhu zvese zvinotevera. Tanga ne bulk capacitor . Electrolytic isina kuchajiwa inoshanda seDC short kana uchiisa simba. Short iyoyo inodhonza inrush current yakakura, uye surge inoisa simba pa rectifiers, fuses, connectors, uye capacitor pachayo. Sarudza inrush limiter yako kuti ienderane nesimba rakachengetwa uye kuti rinodzokororwa kangani, kwete kungoisa plug-in yekutanga chete.
Capacitor ESR inochinja zvakawanda kupfuura ripple. ESR yakaderera zvikuru inogona kukwidza ma rectifier peak currents, saka enzanisa sarudzo yezvikamu ne layout uye sequence diki pane kuvimba ne capacitor chete. Paunochinja chikamu, tarisa ESR uchienzaniswa ne frequency uye ripple detaing. Ripple current rating uye ESR zvinosarudza kana chikamu chichirarama, kwete capacitance ne voltage chete.
Paramita / Sarudzo | Mhedzisiro paRipple | Mhedzisiro paInrush / Rectifier Stress | Chinyorwa Chekugadzira |
|---|---|---|---|
Capacitor ESR (yakaderera zvakanyanya) | Inochinja ripple inobuda; inoshanda neESL yekubatanidza hum/noise | Kuderera kwakanyanya kweESR kunogona kuwedzera ma "rectifier peak currents" | Kuenzanisa kuburikidza nekurongeka uye sarudzo yekudzivisa diki diki |
Capacitor ESR (yakasiyana neyepakutanga) | Inochinja kubuda kwe ripple uye kugadzikana kwe control-loop | Inochinja maitiro ekumhanya-mhanya | Tarisa ESR vs frequency uye ripple decreation |
Chiyero cheRipple current | Chinotsiva chine mwero wakaderera chinogona kukurumidza kutsva uye kukura nekukurumidza | - | Ripple current uye ESR zvinosarudza kupona |
Bulk capacitance | - | Electrolytic isina kuchajiwa inoita kunge DC yapera simba pakugadzirisa | Shandisa NTC, active limiter, kana pre-charge resistor/relay |
Kuisa rectifier/return node | Kuisa capacitor pedyo ne rectifier kunoderedza ripple coupling | - | Kuisa nyeredzi pasi uye kusefa kweRC/LC zvinobatsira njanji dzinonzwa kugadzikana |
Ma capacitor akafanana | Inowedzera kugona kwe ripple uye inoderedza ESR inoshanda | - | Nzira dzekufambisa mhangura dzakafanana uye nzvimbo dzakafanana dzema "loop" dzinogovana magetsi zvakaenzana |
Isa bulk capacitor pedyo ne rectifier uye return node. Star grounding uye RC kana LC filtering pa sensitive rails zvinoderedza hum uye noise coupling. Paralleling capacitors inowedzera kugona kwe ripple uye inoderedza ESR inoshanda, chero bedzi iwe uchiisa copper zvakaenzana uye uchienzanisa loop areas kuitira kuti current share zvakaenzana.
Kana muchina weNTC uchimhanya-mhanya, thermistor yakachipa uye iri nyore, asi inoshanda nesimba uye inopedza simba mushure mekutanga. Kuderedza mashandiro emagetsi kunodhura zvakanyanya uye kunoda logic yekudzora, asi kunobvisa kurasikirwa kwakagadzikana. Yera headroom yekupisa uchienzanisa nemutengo wezvinhu uye kuoma kwekugadzira usati wasarudza.
PFC, Y Capacitors, uye CM Chokes
Danho rePFC rinowedzera ruzha rwaro rwekuchinja pamusoro pechinoshandura simba chikuru. Kuchinja kwaro kakawanda uye maharmoniki zvinobatana nesefa yako yekuisa, saka tora PFC nesefa sedambudziko rimwe chete rekugadzira. Tarisa kona yesefa uchitarisa kushanduka kwePFC, wobva wasimbisa kudzikira kwesimba pabhenji.
Ma capacitor ekuchengetedza anogara muEMI filter kumberi kwemuchina, kazhinji padivi pe ferrite chokes pa input cable uye common-mode kana differential-mode chokes muzvikamu zvekusefa. Ma capacitor eClass Y anobata ruzha rwe common-mode nekupa shared shunt point ku earth. Kuti AC ipinde muDC supply, capacitor imwe yeY inobatanidza tambo ne earth uye imwe inobatanidza neutral ne earth.
Ma-Y-capacitors akagadzirwa kuti abvise ruzha rwe common-mode uye anobatanidzwa pakati pemutsetse nechassis. Zvigadzirwa zve AC front-end zvinoshandisa integral input filter ine common-mode choke pamwe chete neY-capacitors neX-capacitors.
chikamu
Kuiswa (Kubatana)
Basa muEMI Filtering
Y capacitors (CY)
Kubva pamutsetse kuenda kupasi uye kubva pakusava nekwakarerekera kuenda kupasi
Sefa ruzha rwemodhi yakajairika
Kudzipwa kwemaitiro akafanana (L1, L2)
Munhevedzano paMutsetse uye Neutral
Ipa inductance yekusefa kwe common-mode
Ma capacitor eX (CX)
Kubva pamutsetse kuenda kune wakasununguka
Ruzha rwemhando yedhizaini yefirita
Isa CM choke pamberi peY capacitors munzira iripo, uye chengetedza Y capacitor kudzoka iri pfupi uye yakananga ku chassis. Ma return traces marefu anowedzera inductance uye anokuvadza shunt. Iyi setup ndiyo musimboti we low-emi design mu switched-mode ac/dc supplies, uye inonyanya kukosha kana uchisarudza emi filters kuti uwane tight limits. Good conducted emi performance mu ac/dc converters zvinoenderana ne front-end geometry iyi pamwe chete ne part values. Bata ac-dc conversion se chain: rectifier, bulk stage, PFC, wozo filters. Link yega yega inoumba emissions dzaunofanira kudzvinyirira.
Topology uye Sarudzo dzeTransformer
Kutengeserana kweFlyback vs. LLC Resonant
Topology yaunosarudza inogadzirisa ruzha rwako usati watosarudza chikamu chefirita. Flyback chikamu chemhuri yePWM hard-switching. Transistor inobatidza magetsi apo voltage yakakura ichiri pamusoro payo. Parasitic capacitance inochaja kusvika pavoltage iyoyo uye yobva yadurura simba rayo kuburikidza netransistor painobatidza. Simba iroro rinobuda sekupisa uye se emi.
Chinoshandura resonant cheLLC chinoshanda nenzira yakasiyana. Tangi rayo resonant rinobatanidza turn-on ne natural voltage uye current waveforms, saka switch yacho haioni zero voltage (ZVS). Soft switching inoderedza kurasikirwa kwe capacitive dump. Mugumisiro wacho unoshanda zviri nani pamagetsi akakwira, uko hard-switched flyback inoomerwa.
Paunhu | fly-back | LLC Resonant |
|---|---|---|
Kuchinja maitiro | Kuchinja-chinja kwakasimba pasi pemagetsi akashandiswa | Kuchinja-chinja zvinyoro nyoro kuburikidza netangi resonant (ZVS) |
Kurasikirwa kwe "turn-on" | Simba remagetsi rinodonhedzwa sekupisa uye emi | Kuchinja kwakabatana nemaitiro echisikigo emagetsi |
Zvinoreva EMI | Zvakaipa pahuwandu hwakawanda uye voltage yakakwira | Kurasikirwa kwakaderedzwa, kuwirirana kwakawedzerwa |
Kuchinjana kwekugadzira | Mutemo uri nyore | Mutemo weEMI uri nani, wakaoma kunzwisisa |
Unobhadhara kuti uwane LLC nekudzora kwakaoma. Kudzora kubuda kwemagetsi kunowanzoda frequency modulation ukuwo dhizaini yacho ichibata ZVS. Sarudza flyback yesimba shoma uye kudzora kuri nyore. Sarudza LLC kana kushanda zvakanaka uye kuburitsa magetsi zvese zvichikosha pasimba rakakwirira.
Kugadzira Transformer uye Mhinduro dzeOptocoupler
Transformer inoshanda seantenna pamwe chete nechikamu chemagnetic. Maitiro aunoita mawindings muhwindo anokanganisa zvakananga leakage inductance uye parasitic capacitance, uye zvese izvi zvinoumba electromagnetic interference uye efficiency. Tight layering inochengetedza leakage yakaderera, izvo zvinoderedza simba rinofanira kutorwa ne snubber yako kana clamp. Interleaving inosimbisawo coupling, asi inogona kukwidza capacitance.
Kubatana kwe capacitance kunosanganisa ruzha rwe common-mode pamusoro pechivharo chekuzviparadzanisa. Capacitance yakakura inokanganisa mashandiro e common-mode uye inoisa mutoro wakawanda pamafirita ako e emi. Chimiro chesandwich (primary-secondary-primary) chinoderedza kubuda kwemvura, kunyangwe zvichiita kuti insulation iome. Shield windings uye common mode chokes zvinowanzodiwa kuti zvisvike pamiganhu inofambiswa uye inopfuudzwa.
Cherechedza: sarudza dhayamita yewaya nemaune. Dhayamita diki inoderedza simba rezvipembenene uye ganda, asi inodhura huwandu hwemagetsi akawandisa.
Chinovhara feedback loop ye optocoupler ne network yayo yekubhadharisa mari kubva pa switching node, uye bvisa feedback trace kubva pa transformer gap. Ruzha rwunobatana munzira yekupindura runoratidzika se jitter, uye jitter inoparadzira emi spectrum nenzira dzisina kugadziriswa firita yako. Mukushandura ac-dc, tora transformer, barrier, uye feedback loop sedambudziko rimwe chete re layout.
Maitiro Ekugadzira EMC neEMI eKuronga
Kuiswa Kwesefa uye Nzira Dzemazuva Ano Dzakawanda
Maitiro akanaka ekugadzira EMC neEMI anotanga nenzira yekudzoka. High-frequency current inotora nzira yekushomeka kushoma, kwete nzira yawakadhirowa pane schematic. Isa simba iroro pasi rakasimba, uye rinoramba riri pasi petrace. Dzivisa kupatsanuka kwepasi pasi petrace dzehigh-frequency. Kana usingakwanise kudzivirira kupatsanuka, riise pamwe chete ne stitching capacitor.
Isa mafirita ako ekupinda panzvimbo chaipo pechinobatanidza, ruzha rusati rwapararira. Ramba uchichinja maregulator kure neRF nezvikamu zveanalog. Chengetedza maretrace epamusoro-soro ari pedyo, uye shandisa mabend e45-degree kana akakombama panzvimbo pe90-degree.
Layout Strategy | Kudzidzira Kunokosha | Guidance |
|---|---|---|
Ndege yepasi yakasimba | Ipai jira rakazara pasi | Inochengetedza kudzoka kwemagetsi pasi pemutsara |
Kupatsanurwa kwevhu | Maburiro ane ma capacitor ekusona | Kusona ma capacitor paburi |
Guard traces | Mitsetse inonamira pamativi, yakakuyiwa nezvidimbu | Vias spaced λ/20; crosstalk yakachekwa kusvika ~20 dB |
Kudonha | Zvikamu zveCeramic, zvishoma-ESL zviri pedyo nemagetsi | 0.01–0.1 µF mukati me 1–2 mm kubva pamapini |
Kudzora impedance | Match trace impedance kune system | 50 Ω yeRF; FR-4 εr ≈ 4.2 |
Paunosarudza mafirita eEMI, tarisa kuti chikamu chacho chakamira papi, kwete chete kukosha kwacho. Sefa yakaiswa mushure mekutevera kwenguva refu inotora ruzha rwekuti chiratidzo chacho chatobuda. Edza mafirita eEMI pabhodhi chairo, nenzira chaiyo yekudzoka. Kusefa kunoshanda chete kana shunt capacitor iine nzira pfupi, yakananga pasi.
Cherechedza: capacitor inopatsanurwa yakaiswa kure nepini inowedzera inductance uye inorasikirwa nemhedzisiro yayo pahuwandu hwakawanda.
Kukwenya, Kubvisa, uye IEC 62368 Kupatsanura
Nzvimbo yekuchengetedza inoderedza marongerwo efirita yako usati waita basa remagetsi. IEC 62368 inoisa nzvimbo yekutsvedza uye nzvimbo yaunofanira kubata pamusoro pechidziviriro chekuzviparadzanisa. Ma capacitor eY nema common mode chokes anogara panzvimbo iyoyo. Mapedhi avo, ma trace, uye ma slots anofanirwa kuremekedza daro rinodiwa.
Yera kukambaira pamusoro uye nzvimbo iri mumhepo. Nzvimbo yakachekwa mubhodhi inosimudza kukambaira pasina kuwedzera kukwirira. Dzorera Y capacitor zvakananga kune chassis, uye chengeta mamwe madonhwe kunze kwenzvimbo iyoyo. Tarisa nzvimbo zvakare mushure mekufambisa chikamu chefirita kuti uone kana paine emissions. Marongerwo anopfuura miganhu inofambiswa anogona kuramba asina kunaka pakuongorora kwekuchengetedza.
Mitemo, Miganhu, uye Kutevedzera Mutemo Pamberi
CISPR 32 ne EN 55032 Miganhu Yakaitwa Uye Yakasvibirwa
CISPR 32 ne EN 55032 dzinoisa miganhu yekuburitsa magetsi yaunofanira kunanga pamidziyo yemultimedia. Mutemo uyu unosanganisira zvese zvinoburitswa nezvinoburitswa nemwaranzi. Miganho inofambiswa inoshanda kubva pa9 kHz kusvika pa30 MHz pamidziyo yekutengeserana. Miganho inofambiswa nemwaranzi inobva pa30 MHz zvichikwira. Ac/dc yako yekumberi inogara pamain, saka inotarisana nemuganhu wakazara unofambiswa nemwaranzi. DC/DC stage iri pasi perwizi inoona sosi yakanyarara, asi ruzha rwayo rwekuchinja ruchiri kudzoka kuburikidza ne converter. Tora AC input senzvimbo yekuyedza yakanyanya kuomarara.
LISN yaunoshandisa inoenderana nerudzi rwekuisa. Main eAC ekutengesa anoda network ye50 μH + 5 Ω || 50 Ω, senge Tekbox TBLC08. DC automotive work inoshandisa network ye5 μH || 50 Ω, senge Tekbox TBOH01. Ose anopa kuverenga kunodzokororwa pasina anechoic chamber.
Kuedzwa Kwemutemo Pamberi Pekutevedzera Mutemo Pabhenji
Kushanda kwepabhenji kunobata matambudziko mazhinji usati waenda kuchipatara. Tevedzera matanho aya:
Tsvaga chiyero chaunoda, senge CISPR 32 kana EN 55032.
Gadzirai spectrum analyzer ine pre-amplifier, ne near-field probe set, uye LISN pamusoro pe ground plane hombe.
Skena bhodhi netambo uchishandisa ma probe ari pedyo nemunda kuti uwane nzvimbo dzinopisa.
Gadzirisa marongerwo, kudzivirira, kana kusefa, wobva waedzazve woenzanisa.
Tumira kuti uwane chitupa kana mari yacho yave pachena.
Ma probe eNear-field anoshanda chete ari pedyo, masendimita mashoma. Anopa kuverenga kwakaenzana, saka ashandise kuwana masosi, kwete kusimbisa miganhu. Muganho we transient unosungirwa. Ma AC turn-on transients anogona kuburitsa kusvika ku ±325 V muma mixer diodes akayerwa kubva ku +20 dBm kusvika ku +30 dBm RF. Muganho wakaita seTekbox TBFL1 unovhara kubuda kwe +11 dBm pasi pe5 W overloads.
Nzvimbo yekuchengetedza pasi peIEC 62368 inodzivisa basa iri. Mapedhi eY capacitor uye CM choke traces dzinofanira kuchengetedza nzvimbo inodiwa yekutsvedza uye nzvimbo yekubvisa. Tarisa nzvimbo zvakare mushure mekuchinja kwese kwese kwese kwesefa.
Kuchinjana kweThermal, Enclosure, uye DFM
Kupisa, Kudzivirira, uye Mhedzisiro Yekuvharira
Kupisa nekudzivirira zvese zvinotora kamuri rimwe chete mukati memuchina wekushandura. Magadzirirwo enzvimbo, kufamba kwemhepo, uye kwaunoisa zvikamu zvese zvinokanganisa kupisa kwezvinhu. Unofanira kutarisa kuti zvinhu zviri mukati meimba yekupedzisira, kwete pabhenji rakavhurika. Chikamu chinogara chakatonhorera pabhenji chinogona kuongorora chiyero chayo kana bhokisi ravharwa.
Kumhanya usingamire kana munzvimbo dzakaoma kunoda mwero wekupisa wakawedzerwa . Mwero iwoyo unofukidza kukwegura, kuunganidzwa kweguruva, uye mamiriro ezvinhu akaipisisa. Munzvimbo diki dzine mhepo shoma, kunyangwe kurasikirwa kudiki kwekushanda kunogona kuderedza simba rinoshanda. Ronga bhajeti rekupisa usati waisa dhizaini yemakanika.
Kudzivirira kunochinja-chinja zvakananga. Module yakaiswa pabhodhi inowanzogara pedyo nekubatanidza kwekupinda. Kudzivirira kusina simba kunoita kuti kukanganiswa kwemagetsi kugadzire ruzha rwunofambiswa pakubatanidza ikoko. Mapurasitiki ekuvhara mamodule haawanzo ratidza kuvharwa zvachose. Kiti yekesi inogona kucheka kuburitswa kwemhepo kunobatana nemaconductor emagetsi. Sanganisa matanho emakanika neemagetsi: kudzivirira, kuronga kwakanyatsonaka, nzvimbo diki dzezvitenderedzo, uye mapuraneti epasi akasimba, pamwe nekusefa, kupatsanura, kudzikamisa, uye kuyambuka. Musanganiswa iwoyo unokubatsira kusvika pazvinangwa zvekutevedzera mitemo zvakaita seEN 55022 Class B.
Zvipingamupinyi zveDFM paZvikamu zveFirita
Mafirita ako e-emi anofanira kupfuura nemumutsetse wekubatanidza , kwete murabhoritari chete. Maitiro akajairika anogumira pakupwanya waya zvakanaka panguva yekubata. Ma capacitor makuru eX anoda nzvimbo dzinodzivirira marongerwo ako. Sarudza zvikamu zvine tsoka dzakajairwa uye kurongedza mareel. Iva nechokwadi chekuti muchina wekuisa unogona kubata saizi yemuviri nehuremu.
Zvikamu zvekunyorovesa zvinowedzera mutengo uye matanho ekudzoreredza mvura. Capacitor yekunyorovesa mvura ine kakapetwa katatu kusvika kana kupfuura capacitor yekupinda inotora nzvimbo yebhodhi, uye ingangoda dielectric yakasiyana. Tarisa chimiro chesolder chechikamu chimwe nechimwe chakawedzerwa. Bvunza mugadziri wako nezvenjodzi yekutemwa nematombo pama capacitor madiki ari pedyo nekupisa kukuru.
Nzvimbo dzekuyedza uye ma tuning pads zvinobatsira panguva yebasa rekugadzirira kutevedzera mitemo. Zvinowedzerawo mutengo. Sarudza nekukurumidza kuti ma pads api anogara uye api aunobvisa. Chengetedza marongerwo efirita akagadzikana mukati mekugadzirisa, nekuti pad yakafambiswa inoshandura parasitic coupling uye inochinja mhedzisiro yako. Tora shanduko yega yega yefirita seshanduko yedhizaini inoda kuongororwa patsva.
Tanga nerudzi rweruzha uye nzira yekubatanidza. Wobva wasarudza woisa mafirita kuti aenderane. Kurongeka ikoko kunokubatsira kuti usafungidzire.
Maitiro matatu ndiwo anorema zvakanyanya. Nyorovesa nhanho yega yega yeLC kuitira kuti zvinopinzwa zvirambe zvakagadzikana. Remekedza miganhu yeY capacitor neIEC 62368, kunyangwe mushure mekufambisa chikamu. Shandisa bench pre-compliance nekukurumidza, kuitira kuti emissions dzakaitwa dzionekwe murabhoritari isati yaita.
Bata emi sebasa rinodzokororwa padanho rebhodhi, kwete kugadzirisa mushure mekukundikana:
Isa zvinangwa zveEMC panguva yekutsanangurwa.
Edza zvishoma nezvishoma uchishandisa spectrum analyzer uye near-field probes.
Gadzirisa chete mafrequency asina kushanda zvakanaka.
Tarisa mitengo yezvigadzirwa nekukurumidza. Kuchengetedza kunodzivirira kupisa, uye zvivakwa zvinogadzirwa zvakanaka zvinokwidza mutengo. Uya nemugadziri wemafirita ako nemutengesi wePCB muongororo yekushandurwa kweac-dc. Kuchinja kudiki kwezvinodiwa kunogona kumanikidza dhizaini yakazara.
FAQ
Ndeipi nzira yeruzha yaunofanira kutanga watanga kana scan ikakundikana?
Patsanura mamodhi usati wabata chikamu. Batanidza probe yeRF current kutenderedza mutsetse uye neutral pamwe chete kuti uverenge common mode current. Tungamira waya mbiri munzira dzakasiyana kuburikidza neprobe kuti uverenge differential mode. Enzanisa kuverenga kwese, wobva waisa saizi ye emi filter yako kune dominant mode.
Sei LC stage ichitadza kumisa ruzha rwe common mode?
Mwenje wemodhi yakasiyana unoyerera padanho rimwe chete wodzoka kune rimwe. Mwenje wemodhi yakafanana inoyerera nenzira imwe chete pamitsetse yese miviri uye inodzoka kuburikidza nechassis kana earth. Chikamu cheLC chinovhara nzira yekutanga chete. Unoda common mode choke pamwe neY capacitor pakupinda kuti udzivise wechipiri.
Unoita sei kuti firita isarira kana kutenderera?
Chengeta filter output impedance iri pasi peconverter input impedance iri mu control-loop bandwidth. Iyi ndiyo criteria yaMiddlebrook. Wedzera damping kuitira kuti peak pa cut-off frequency irambe yakaderera, uye tarisa mhinduro uchishandisa frequency response analysis pane time-domain testing chete.
Mafirita ekuisa anofanira kugara papi pabhodhi?
Zviise panzvimbo inobatidza ruzha, ruzha rusati rwapararira mubhodhi. Chengeta kudzoka kweY capacitor kuri kupfupi uye kwakananga kuchasi. Shunt capacitor inoda nzira yakasimba yekuenda pasi, kana kuti trace inductance inogona kukanganisa kushanda kwayo. Edza mafirita ari pabhodhi chairo nenzira chaiyo yekudzoka.
