Menene ka'idar da'irar tuƙi na MOSFET mai ƙarfi?

MOSFET mai ƙarfi iri ɗaya, amfani da da'irori daban-daban zai sami halaye na canzawa daban-daban. Yin amfani da kyakkyawan aiki na da'irar kewayawa zai iya sa na'urar sauya wutar lantarki ta yi aiki a cikin yanayin sauyawa mai mahimmanci, yayin da rage lokacin sauyawa, rage asarar sauyawa, shigar da ingantaccen aiki, aminci da aminci suna da mahimmanci. Sabili da haka, fa'ida da rashin amfani da keɓaɓɓiyar kewayawa kai tsaye yana shafar aikin babban kewayawa, ƙaddamar da ƙirar ƙirar ƙirar yana ƙara mahimmanci. Thyristor ƙananan girman, nauyi mai nauyi, babban inganci, tsawon rai, sauƙin amfani, yana iya dakatar da gyarawa da inverter sauƙi, kuma ba zai iya canza tsarin kewayawa a ƙarƙashin yanayin canza girman mai gyarawa ko inverter current.IGBT wani hadadden abu ne. na'urar taMOSFETda kuma GTR, wanda ke da halaye na saurin sauyawa da sauri, kyakkyawan kwanciyar hankali na thermal, ƙaramin ƙarfin tuki da kewayawa mai sauƙi, kuma yana da fa'idodin ƙaramin faɗuwar wutar lantarki a kan-jihar, ƙarfin juriya da ƙarfin halin yanzu. IGBT a matsayin na'urar fitarwa ta al'ada, musamman a wurare masu ƙarfi, an yi amfani da su a cikin nau'i daban-daban.

Kyakkyawan da'irar tuki don manyan na'urori masu sauyawa MOSFET yakamata su cika buƙatu masu zuwa:

(1) Lokacin da aka kunna bututun wutar lantarki, da'irar tuƙi na iya samar da tushe mai tasowa mai sauri, ta yadda za a sami isasshen ƙarfin tuki lokacin da aka kunna shi, don haka rage asarar kunnawa.

(2) Yayin tafiyar da bututu mai sauyawa, tushen halin yanzu da MOSFET direban da'irar ke bayarwa na iya tabbatar da cewa bututun wutar lantarki yana cikin yanayin tafiyar da komai a ƙarƙashin kowane yanayin ɗaukar nauyi, yana tabbatar da ƙarancin tafiyarwa. Domin rage lokacin ajiya, ya kamata na'urar ta kasance cikin yanayin jikewa mai mahimmanci kafin rufewa.

(3) kashewa, da'irar tuƙi ya kamata ta samar da isassun kayan aikin juzu'i don fitar da sauran dillalai da sauri a cikin yankin tushe don rage lokacin ajiya; da ƙara juzu'i na yanke wutar lantarki, ta yadda mai karɓar halin yanzu ya faɗi da sauri don rage lokacin saukowa. Tabbas, rufewar thyristor har yanzu yafi ta hanyar juzu'in ƙarfin lantarki na anode don kammala rufewar.

A halin yanzu, thyristor yana tuƙi tare da adadin kwatankwacin adadin kawai ta hanyar na'ura mai canzawa ko keɓewar optocoupler don raba ƙarshen ƙarancin wutar lantarki da ƙarshen ƙarfin lantarki, sannan ta hanyar kewayawa don fitar da jigilar thyristor. A kan IGBT don amfanin yanzu na ƙarin IGBT drive module, amma kuma hadedde IGBT, tsarin kula da kai, ganewar kansa da sauran kayan aikin IPM.

A cikin wannan takarda, don thyristor muna amfani da shi, ƙirƙira da'ira na gwajin gwaji, kuma dakatar da gwajin gaske don tabbatar da cewa yana iya tuƙi thyristor. Dangane da tukin IGBT, wannan takarda ta fi gabatar da manyan nau'ikan IGBT ɗin na yanzu, da kuma da'irar da'irarsu, da kuma abin da aka fi amfani da shi na keɓancewa na optocoupler don dakatar da gwajin simulation.

2. Binciken da'ira na Thyristor gabaɗaya yanayin aiki na thyristor sune:

(1) thyristor ya karɓi reverse anode voltage, ba tare da la'akari da ƙofar ya karɓi irin ƙarfin lantarki ba, thyristor yana cikin yanayin kashewa.

(2) Thyristor yana karɓar ƙarfin lantarki na anode na gaba, kawai a yanayin ƙofar yana karɓar ingantaccen ƙarfin lantarki thyristor yana kunne.

(3) Thyristor a cikin yanayin tafiyarwa, kawai wani tabbataccen ƙarfin lantarki na anode, ba tare da la'akari da ƙarfin ƙofar ba, thyristor ya nace akan gudanarwa, wato, bayan aikin thyristor, ƙofar ya ɓace. (4) thyristor a cikin yanayin gudanarwa, lokacin da babban ƙarfin lantarki (ko na yanzu) ya ragu zuwa kusa da sifili, rufewar thyristor. Mun zaɓi thyristor shine TYN1025, ƙarfin jurewarsa shine 600V zuwa 1000V, na yanzu har zuwa 25A. yana buƙatar ƙarfin wutar lantarki na gate ɗin shine 10V zuwa 20V, ƙarfin halin yanzu shine 4mA zuwa 40mA. kuma kulawarsa shine 50mA, injin na yanzu shine 90mA. ko dai DSP ko CPLD faɗakarwar siginar girman siginar muddin 5V. Da farko dai, idan dai girman 5V zuwa 24V, sannan ta hanyar 2:1 kebewar transfoma don canza siginar faɗakarwa na 24V zuwa siginar faɗakarwa na 12V, yayin da yake kammala aikin keɓancewar wutar lantarki na sama da ƙasa.

Zane da bincike na gwaji

Da farko, da'irar haɓakawa, saboda keɓewar da'ira mai canzawa a cikin matakin baya naMOSFETNa'urar tana buƙatar siginar faɗakarwa na 15V, don haka buƙatar farko ta haɓaka siginar faɗakarwa na 5V zuwa siginar jawo 15V, ta hanyar siginar MC14504 5V, ta canza zuwa siginar 15V, sannan ta CD4050 akan fitowar siginar siginar 15V na siginar, tashar 2 an haɗa shi da siginar shigarwar 5V, tashar 1 an haɗa shi da tashar tashar tashar tashar tashar tashar tashar tashar tashar tashar tashar 2 ta haɗa zuwa siginar shigarwar 5V, tashar 1 ita ce. an haɗa da fitarwa na siginar faɗakarwa na 15V.

Bangare na biyu shine kebewar da'ira, babban aikin da'irar shine: 15V siginar faɗakarwa, wanda aka canza zuwa siginar faɗakarwa 12V don kunna baya na aikin thyristor, kuma don yin siginar faɗakarwa na 15V da nisa tsakanin baya. mataki.

Ka'idar aiki na kewaye shine: sabodaMOSFETIRF640 drive irin ƙarfin lantarki na 15V, don haka, da farko, a J1 damar yin amfani da 15V square kalaman siginar, ta hanyar resistor R4 alaka da regulator 1N4746, sabõda haka, da jawo irin ƙarfin lantarki ne barga, amma kuma don sa fararwa irin ƙarfin lantarki ne ba ma high. , ƙone MOSFET, sa'an nan kuma zuwa MOSFET IRF640 (a gaskiya, wannan shi ne mai sauyawa tube, da iko na baya karshen bude da kuma rufe. Sarrafa da baya ƙarshen kunnawa da kashewa), bayan sarrafa yanayin aikin siginar tuƙi, don samun damar sarrafa lokacin kunnawa da kashewa na MOSFET. Lokacin da MOSFET ke buɗewa, daidai da ƙasan D-pole, a kashe lokacin da yake buɗewa, bayan kewayen ƙarshen baya daidai da 24 V. Kuma transfomer ta hanyar canjin wutar lantarki ne don yin daidai ƙarshen siginar fitarwa na 12 V. . Ƙarshen dama na na'ura yana haɗi zuwa gada mai gyara, sannan siginar 12V yana fitowa daga haɗin X1.

Matsalolin da aka fuskanta yayin gwajin

Da farko dai, lokacin da aka kunna wutar, fis ɗin ya busa ba zato ba tsammani, daga baya kuma da aka duba da'ira, an gano cewa an sami matsala wajen ƙirar da'ira ta farko. Da farko, don inganta tasirin fitowar bututunsa, 24V ƙasa da rabuwar ƙasa 15V, wanda ya sa aka dakatar da ƙofar MOSFET ta ƙofar G wanda ke daidai da bayan sandar sandar S, wanda ya haifar da tayar da ƙarya. Jiyya shine haɗa ƙasan 24V da 15V tare, kuma don dakatar da gwajin, da'irar tana aiki akai-akai. Haɗin kewayawa al'ada ne, amma lokacin shiga cikin siginar tuƙi, MOSFET zafi, da siginar tuƙi na ɗan lokaci, fis ɗin yana busa, sannan ƙara siginar tuƙi, fis ɗin yana busa kai tsaye. Bincika da'irar gano cewa babban matakin sake zagayowar aikin siginar tuƙi ya yi girma da yawa, sakamakon lokacin kunna MOSFET ya yi tsayi da yawa. Tsarin wannan da'irar yana sanya lokacin da MOSFET ta buɗe, 24V ta ƙara kai tsaye zuwa ƙarshen MOSFET, kuma bai ƙara juzu'i mai iyakancewa ba, idan akan lokaci ya yi tsayi da yawa don sa na yanzu ya yi girma, MOSFET lalacewa, Bukatar daidaita yanayin aikin siginar ba zai iya zama babba ba, gabaɗaya a cikin 10% zuwa 20% ko makamancin haka.

2.3 Tabbatar da da'irar tuƙi

Domin tabbatar da yiwuwar da'irar drive, muna amfani da shi don fitar da da'irar thyristor da aka haɗa a jere tare da juna, da thyristor a cikin jerin tare da juna sannan kuma anti-parallel, samun dama ga kewayawa tare da reactance inductive, wutar lantarki. 380V AC ƙarfin lantarki tushen.

MOSFET a cikin wannan da'irar, thyristor Q2, Q8 yana jawo siginar ta hanyar shiga G11 da G12, yayin da Q5, Q11 ke jawo siginar ta hanyar G21, G22. Kafin a karɓi siginar tuƙi zuwa matakin ƙofar thyristor, don haɓaka ikon hana tsangwama na thyristor, ƙofar thyristor an haɗa shi da resistor da capacitor. Ana haɗa wannan da'ira zuwa inductor sannan a saka shi cikin babban kewaye. Bayan sarrafa kusurwar gudanarwa na thyristor don sarrafa babban inductor zuwa babban lokacin kewayawa, manyan da'irori na sama da ƙananan da'irori na kusurwar lokaci na siginar fararwa na rabin sake zagayowar, G11 na sama da G12 shine siginar faɗakarwa gaba ɗaya. ta hanyar da'irar da'irar gaban matakin na keɓewar taswirar keɓe da juna, ƙananan G21 da G22 kuma sun keɓe daga wannan hanyar siginar. Sigina guda biyu suna haifar da anti-parallel thyristor circuit tabbatacce da mummunan gudanarwa, sama da tashar 1 an haɗa shi da duk ƙarfin lantarki na thyristor, a cikin tasirin thyristor ya zama 0, da 2, 3 tashar an haɗa ta da kewayen thyristor sama da ƙasa. siginar faɗakarwa na hanya, tashar 4 ana auna ta hanyar kwararar duk halin yanzu na thyristor.

Tashar 2 ta auna siginar faɗakarwa mai kyau, wanda aka kunna sama da jigilar thyristor, halin yanzu yana da kyau; Tashar ta 3 ta auna sigina mai juyawa, yana haifar da ƙananan da'irar tafiyar thyristor, halin yanzu mara kyau.

3.IGBT drive circuit na taron karawa juna sani IGBT drive circuit yana da yawa na musamman buƙatun, taƙaita:

(1) fitar da adadin tashi da faɗuwar bugun bugun bugun jini ya zama isasshe babba. igbt yana kunna, ana ƙara babban gefen gate mai ƙarfi zuwa gate G da emitter E tsakanin ƙofar, ta yadda za a kunna shi da sauri don isa mafi guntuwar lokacin don rage kunna hasara. A cikin IGBT kashewa, gate drive kewaye ya kamata samar da IGBT saukowa gefen ne sosai m kashe wutar lantarki, da kuma zuwa ga IGBT gate G da emitter E tsakanin dace reverse bias ƙarfin lantarki, sabõda haka, IGBT sauri kashewa, gajarta da kashe lokaci, rage. asarar kashewa.

(2) Bayan gudanar da IGBT, wutar lantarki da na yanzu da na'urar kewayawa ta gate ɗin ke bayarwa ya kamata su zama isashen girman ƙarfin lantarki na IGBT da halin yanzu, ta yadda ƙarfin wutar lantarki na IGBT koyaushe yana cikin cikakken yanayi. Matsakaicin wuce gona da iri, ƙarfin tuƙi da kewayen ƙofar kofa ke bayarwa yakamata ya isa don tabbatar da cewa IGBT bai fita daga yankin jikewa da lalacewa ba.

(3) Ya kamata a ba da wutar lantarki mai inganci na IGBT don ɗaukar ƙimar da ta dace, musamman a cikin gajeriyar tsarin aiki na kayan aikin da aka yi amfani da su a cikin IGBT, yakamata a zaɓi ingantaccen ƙarfin lantarki zuwa mafi ƙarancin ƙimar da ake buƙata. Canja aikace-aikacen ƙarfin wutar lantarki na IGBT yakamata ya zama 10V ~ 15V don mafi kyau.

(4) Tsarin rufe IGBT, ƙarancin wutar lantarki mara kyau da ake amfani da shi a tsakanin ƙofar - emitter yana taimakawa ga saurin rufe IGBT, amma bai kamata a ɗauka da girma ba, ɗaukar talakawa -2V zuwa -10V.

(5) a cikin yanayin manyan lodin inductive, saurin sauyawa yana da cutarwa, manyan lodin inductive a cikin IGBT saurin kunnawa da kashewa, za su samar da mitoci mai girma da girma da kunkuntar nisa na karu irin ƙarfin lantarki Ldi / dt , Karu ba sauƙin sha ba, mai sauƙin ƙirƙirar lalacewar na'urar.

(6) Kamar yadda IGBT ake amfani da high-voltage wurare, don haka da drive ya kamata ya kasance tare da dukan iko da'ira a cikin m na tsanani kadaici, da talakawa amfani da high-gudun Tantancewar hada biyu kadaici ko na'ura mai canzawa hada biyu kadaici.

Matsayin kewayawa

Tare da haɓaka fasahar haɗin gwiwa, da'irar tuƙi na ƙofar IGBT na yanzu galibi ana sarrafa shi ta hanyar haɗaɗɗun kwakwalwan kwamfuta. Yanayin sarrafawa har yanzu yana da nau'ikan iri uku:

(1) nau'in fararwa kai tsaye babu keɓantacce na lantarki tsakanin siginar shigarwa da fitarwa.

(2) keɓewar mai canzawa tsakanin siginar shigarwa da fitarwa ta amfani da keɓantawar bugun jini, matakin keɓewar ƙarfin lantarki har zuwa 4000V.

Akwai hanyoyi guda 3 kamar haka

Hanyar wucewa: ana amfani da fitowar taswirar ta biyu don fitar da IGBT kai tsaye, saboda iyakancewar daidaitawar volt-na biyu, ana amfani da shi ne kawai ga wuraren da yanayin aikin ba ya canzawa da yawa.

Hanyar aiki: mai canzawa kawai yana ba da sigina keɓaɓɓu, a cikin da'irar amplifier filastik ta biyu don fitar da IGBT, tsarin motsi ya fi kyau, amma buƙatar samar da ikon taimako daban.

Hanyar samar da kai: Ana amfani da transformer na bugun jini don watsa duka makamashin motsa jiki da na'ura mai ƙarfi da haɓakawa da fasaha don watsa siginar dabaru, zuwa nau'ikan nau'ikan isar da kai da fasahar raba lokaci ta hanyar samar da kai, a cikin abin da modulation. -nau'in ikon samar da kai ga gadar gyara don samar da wutar lantarki da ake buƙata, daidaitawa mai girma da fasaha don watsa siginar dabaru.

3. Saduwa da bambanci tsakanin thyristor da IGBT drive

Thyristor da IGBT da'irar tuƙi suna da bambanci tsakanin cibiyar makamancin haka. Da farko dai, ana buƙatar da’irorin tuƙi guda biyu don ware na’urar sauya sheka da na’urar sarrafawa daga juna, ta yadda za a guje wa manyan da’irori suna da tasiri a kan na’urar sarrafawa. Sa'an nan, duka biyu suna amfani da siginar motar ƙofar don kunna na'urar kunnawa. Bambanci shine cewa thyristor drive yana buƙatar sigina na yanzu, yayin da IGBT ke buƙatar siginar lantarki. Bayan sarrafa na'urar canzawa, ƙofar thyristor ta rasa ikon yin amfani da thyristor, idan kuna son rufe thyristor, yakamata a ƙara tashoshin thyristor zuwa wutar lantarki ta baya; kuma kashewar IGBT kawai yana buƙatar ƙarawa zuwa ƙofar ƙarancin ƙarfin tuƙi, don rufe IGBT.

4. Kammalawa

An rarraba wannan takarda zuwa sassa biyu na labarin, ɓangaren farko na buƙatun thyristor drive da'ira don dakatar da labarin, ƙirar da'irar da'irar da ta dace, kuma ƙirar da'irar ana amfani da ita a kan da'irar thyristor mai amfani, ta hanyar kwaikwayo. da gwaji don tabbatar da yuwuwar da'irar tuƙi, tsarin gwajin da aka fuskanta a cikin nazarin matsalolin ya tsaya kuma an magance shi. Kashi na biyu na babban tattaunawa akan IGBT akan buƙatun na'ura mai ba da hanya tsakanin hanyoyin sadarwa, kuma a kan wannan don ƙara gabatar da da'irar IGBT da aka saba amfani da ita a halin yanzu, da kuma babbar hanyar keɓancewa ta optocoupler don dakatar da simulation da gwaji, don tabbatar da yiwuwa na da'irar drive.