Uyini umgomo wesekethe yedrayivu ye-MOSFET yamandla aphezulu?

I-MOSFET enamandla amakhulu efanayo, ukusetshenziswa kwamasekethe ahlukene okushayela kuzothola izici ezihlukile zokushintshwa. Ukusetshenziswa kokusebenza kahle kwesekethe yedrayivu kungenza idivayisi yokushintsha amandla isebenze esimweni esifanele sokushintsha, kuyilapho ifinyeza isikhathi sokushintsha, ukunciphisa ukulahlekelwa kokushintsha, ukufakwa kokusebenza kahle kokusebenza, ukwethembeka nokuphepha kubaluleke kakhulu. Ngakho-ke, izinzuzo kanye nokubi kwesifunda se-drive kuthinta ngokuqondile ukusebenza kwesifunda esiyinhloko, ukulinganisa kokuklama kwesifunda sokushayela kubaluleke kakhulu. I-Thyristor usayizi omncane, isisindo esilula, ukusebenza kahle okuphezulu, impilo ende, kulula ukuyisebenzisa, ingakwazi ukumisa kalula isilungisi kanye ne-inverter, futhi ayikwazi ukushintsha ukwakheka kwesekethe ngaphansi kwesisekelo sokushintsha usayizi we-rectifier noma inverter current.IGBT iyinhlanganisela idivayisi yeI-MOSFETkanye ne-GTR, enezici zejubane lokushintsha ngokushesha, ukuzinza okuhle kwe-thermal, amandla amancane okushayela kanye nesekethe yedrayivu elula, futhi inezinzuzo zokwehla kwama-voltage amancane aku-state, ukumelana ne-voltage ephezulu kanye nokwamukelwa okuphezulu kwamandla. I-IGBT njengethuluzi elivamile elikhipha amandla, ikakhulukazi ezindaweni ezinamandla amakhulu, isetshenziswe ngokuvamile ezigabeni ezihlukahlukene.

Isekethe efanelekile yokushayela yamadivayisi anamandla aphezulu we-MOSFET kufanele ahlangabezane nalezi zidingo ezilandelayo:

(1) Uma ithubhu yokushintsha amandla ivuliwe, isifunda sokushayela singanikeza isisekelo samanje esikhuphuka ngokushesha, ukuze kube namandla okushayela anele lapho ivuliwe, ngaleyo ndlela kunciphise ukulahlekelwa kokuvula.

(2) Ngesikhathi sokuqhutshwa kweshubhu yokushintsha, isisekelo samanje esinikezwa umjikelezo womshayeli we-MOSFET singaqinisekisa ukuthi ishubhu yamandla isesimweni sokuhamba esigcwele ngaphansi kwanoma isiphi isimo somthwalo, okuqinisekisa ukulahleka kokusebenza okuphansi ngokuqhathaniswa. Ukuze unciphise isikhathi sokulondoloza, idivayisi kufanele ibe sesimweni esibucayi sokugcwala ngaphambi kokuvala shaqa.

(3) ukuvala shaqa, umjikelezo wedrayivu kufanele unikeze idrayivu eyisisekelo eyanele ukuze ukhiphe ngokushesha abathwali abasele endaweni eyisisekelo ukuze kuncishiswe isikhathi sokugcina; futhi wengeze i-reverse bias cutoff voltage, ukuze umqoqi wamanje wehle ngokushesha ukuze unciphise isikhathi sokufika. Vele, ukuvala shaqa kwe-thyristor kusese ngokuyinhloko ukwehla kwe-voltage ye-anode ehlehlayo ukuze kuqedelwe ukuvala shaqa.

Njengamanje, i-thyristor ishayela ngenombolo eqhathanisekayo ye-transformer noma i-optocoupler isolation ukuze ihlukanise ukuphela kwe-voltage ephansi kanye nokuphela kwe-voltage ephezulu, bese kuthi ngomjikelezo wokuguqula ukushayela i-thyristor conduction. Ku-IGBT ukusetshenziswa kwamanje kwemojula yokushayela ye-IGBT eyengeziwe, kodwa futhi i-IGBT edidiyelwe, ukuzinakekela kwesistimu, ukuzixilonga kanye namanye amamojula asebenzayo e-IPM.

Kuleli phepha, le-thyristor esiyisebenzisayo, klama isifunda sokuhlola sokushayela, futhi umise ukuhlolwa kwangempela ukufakazela ukuthi ingakwazi ukushayela i-thyristor. Ngokuqondene nokushayela kwe-IGBT, leli phepha lethula ngokuyinhloko izinhlobo eziyinhloko zamanje zedrayivu ye-IGBT, kanye nomjikelezo wedrayivu ohambisanayo, kanye nedrayivu evame ukusetshenziswa kakhulu ye-optocoupler isolation ukuze kumiswe isilingo sokulingisa.

2. Ucwaningo lwesifunda se-Thyristor drive ngokuvamile izimo zokusebenza ze-thyristor yilezi:

(1) i-thyristor yamukela i-voltage ye-anode ehlanekezelwe, kungakhathaliseki ukuthi isango liyakwamukela ukuthi hlobo luni lwe-voltage, i-thyristor isesimweni sokucisha.

(2) I-Thyristor yamukela i-voltage ye-anode eya phambili, kuphela esimweni sesango samukela i-voltage ephozithivu i-thyristor evuliwe.

(3) I-Thyristor esimweni sokuqhuba, i-voltage ethile ye-anode enhle kuphela, kungakhathaliseki ukuthi i-voltage yesango, i-thyristor iphikelele ekuqhubeni, okungukuthi, ngemva kokukhishwa kwe-thyristor, isango lilahlekile. (4) i-thyristor esimweni sokuqhuba, lapho i-voltage yesekethe eyinhloko (noma yamanje) yehla yafinyelela ku-zero, ukuvala shaqa kwe-thyristor. Sikhetha i-thyristor yi-TYN1025, i-voltage yayo yokumelana ingu-600V kuya ku-1000V, yamanje ifika ku-25A. idinga i-gate drive voltage ingu-10V kuya ku-20V, idrayivu yamanje ingu-4mA kuya ku-40mA. futhi ukugcinwa kwayo kungu-50mA, injini yamanje ingu-90mA. kungaba i-DSP noma i-CPLD icupha i-amplitude yesiginali inqobo nje uma i-5V. Okokuqala nje, inqobo nje uma i-amplitude ye-5V ibe ngu-24V, bese ngokusebenzisa isiguquli sokuhlukanisa esingu-2:1 ukuguqula isignali ye-trigger engu-24V ibe isignali ye-trigger engu-12V, ngenkathi iqedela umsebenzi wokuhlukaniswa kwamandla kagesi aphezulu naphansi.

Idizayini yesekethe yokuhlola nokuhlaziya

Okokuqala, i-boost circuit, ngenxa yokuhlukaniswa kwe-transformer circuit in the back stage of theI-MOSFETidivayisi idinga isignali ye-trigger engu-15V, ngakho-ke isidingo sokuqala ukwenza i-amplitude yesiginali ye-trigger engu-5V ibe isignali ye-trigger engu-15V, ngesignali ye-MC14504 5V, eguqulelwe ibe isignali engu-15V, bese nge-CD4050 ekuphumeni kwesignali ye-15V yedrayivu, isiteshi 2. ixhunywe kusiginali yokufaka engu-5V, isiteshi 1 sixhunywe ku-Channel 2 ephumayo sixhunywe kusiginali yokufaka engu-5V, isiteshi 1 ixhunywe ekuphumeni kwesignali ye-trigger engu-15V.

Ingxenye yesibili iyisekhethi ye-isolation transformer, umsebenzi oyinhloko wesekethe yilezi: isignali ye-trigger engu-15V, eguqulwa ibe isignali ye-trigger engu-12V ukuze iqalise ngemuva kokuqhutshwa kwe-thyristor, nokwenza isignali ye-trigger engu-15V kanye nebanga phakathi komhlane. esiteji.

Umgomo wokusebenza wesifunda uthi: ngenxa ye-I-MOSFETI-IRF640 drive voltage ye-15V, ngakho-ke, okokuqala, ekufinyeleleni kwe-J1 kusiginali ye-wave yesikwele engu-15V, nge-resistor R4 exhunywe kusilawuli esingu-1N4746, ukuze i-trigger voltage izinzile, kodwa futhi ukwenza i-trigger voltage ingabi phezulu kakhulu. , kushise i-MOSFET, bese ku-MOSFET IRF640 (empeleni, leli yishubhu yokushintsha, ukulawulwa kokuphela kokuphela kokuvula kanye Ukuvala Lawula ingemuva lokuvula nokucisha), ngemva kokulawula umjikelezo womsebenzi wesiginali yokushayela, ukuze ukwazi ukulawula isikhathi sokuvula nokuvala se-MOSFET. Lapho i-MOSFET ivuliwe, okulingana nendawo yayo ye-D-pole, icishiwe lapho ivuliwe, ngemva kwesekethe engemuva elingana no-24 V. Futhi i-transformer idlula ekushintsheni kwamandla kagesi ukuze yenze isiphetho esifanele sesiginali yokuphuma kwe-12 V. . Ukuphela kwesokudla kwe-transformer kuxhunywe ebhulohweni lokulungisa, bese isignali engu-12V iphuma kusixhumi X1.

Izinkinga okuhlangatshezwane nazo ngesikhathi sokuhlolwa

Okokuqala, lapho amandla evuliwe, i-fuse yaqhuma ngokuzumayo, futhi kamuva lapho ihlola isifunda, kwatholakala ukuthi kunenkinga ngomklamo wokuqala wesifunda. Ekuqaleni, ukuze kube ngcono umphumela wokuphuma kwayo kweshubhu yokushintsha, ukuhlukaniswa komhlaba okungu-24V kanye ne-15V, okwenza isigxobo se-MOSFET sesango elilingana nengemuva lesigxobo sika-S simisiwe, okuholela ekucupheni okungamanga. Ukwelashwa ukuxhumanisa i-24V ne-15V ndawonye, ​​futhi futhi ukuze kumiswe ukuhlola, isekethe isebenza ngokujwayelekile. Ukuxhumeka kwesekethe kuyinto evamile, kodwa lapho ubamba iqhaza kusiginali yokushayela, ukushisa kwe-MOSFET, kanye nesiginali yedrayivu isikhathi esithile, i-fuse iyashaywa, bese wengeza isignali yokushayela, i-fuse ishaywa ngokuqondile. Hlola umjikelezo uthole ukuthi umjikelezo wezinga eliphezulu lomsebenzi wesiginali yokushayela mkhulu kakhulu, okuholela ekutheni isikhathi sokuvula se-MOSFET side kakhulu. Idizayini yalesi sekethi yenza lapho i-MOSFET ivuleka, i-24V yengeze ngqo emaphethelweni e-MOSFET, futhi ayizange ingeze i-resistor ekhawulelwe yamanje, uma i-on-time yinde kakhulu ukwenza yamanje inkulu kakhulu, umonakalo we-MOSFET, isidingo sokulawula umjikelezo womsebenzi wesignali awukwazi ukuba mkhulu kakhulu, ngokuvamile ku-10% kuya ku-20% noma kunjalo.

2.3 Ukuqinisekiswa komjikelezo wedrayivu

Ukuze siqinisekise ukuthi kungenzeka yini isekethe yedrayivu, siyisebenzisela ukushayela isekethe ye-thyristor exhunywe ochungechungeni nomunye nomunye, i-thyristor ochungechungeni nomunye bese kuba i-anti-parallel, ukufinyelela kumjikelezo ngokusabela kwe-inductive, ukunikezwa kwamandla. ingumthombo wamandla kagesi we-380V AC.

I-MOSFET kulo mjikelezo, i-thyristor Q2, isignali ye-Q8 yokuqalisa ngokufinyelela kwe-G11 ne-G12, kuyilapho i-Q5, i-Q11 iqalisa isignali ngokufinyelela kwe-G21, G22. Ngaphambi kokuba isignali yokushayela itholakale ezingeni lesango le-thyristor, ukuze kuthuthukiswe ikhono lokulwa nokuphazamiseka kwe-thyristor, isango le-thyristor lixhunywe ku-resistor kanye ne-capacitor. Lo mjikelezo uxhunywe ku-inductor bese ufakwa kumjikelezo omkhulu. Ngemva kokulawula i-angle conduction ye-thyristor ukuze ulawule i-inductor enkulu esikhathini sokujikeleza esikhulu, amasekhethi aphezulu naphansi we-engeli yesigaba somehluko wesiginali ye-trigger yesigamu somjikelezo, i-G11 engenhla ne-G12 iyisiginali yokuqalisa yonke indlela. ngokusebenzisa isifunda sokushayela sesiteji sangaphambili se-transformer yokuhlukanisa ihlukaniswe komunye nomunye, i-G21 ephansi ne-G22 nayo ihlukaniswe ngendlela efanayo yesignali. Amasignali amabili okuqala aqala i-anti-parallel thyristor circuit conduction positive and negative conduction, ngenhla kwesiteshi esingu-1 sixhunywe kuwo wonke amandla wesifunda se-thyristor, ekuqhubeni kwe-thyristor kuba ngu-0, futhi u-2, u-3 wesiteshi uxhunywe kumjikelezo we-thyristor phezulu naphansi. izimpawu ze-trigger zomgwaqo, isiteshi se-4 silinganiswa ngokugeleza kwayo yonke i-thyristor yamanje.

Isiteshi esingu-2 silinganise isignali ye-trigger enhle, ebangelwa ngaphezu kwe-thyristor conduction, yamanje ilungile; Isiteshi esingu-3 silinganise isignali ye-trigger ehlanekezelayo, icupha isifunda esiphansi se-thyristor conduction, yamanje ayinayo.

I-3.IGBT drive circuit yesemina ye-IGBT drive circuit inezicelo eziningi ezikhethekile, ezifingqiwe:

(1) ukushayela izinga lokukhuphuka nokuwa kwe-voltage pulse kufanele libe likhulu ngokwanele. i-igbt ivuliwe, umkhawulo ohamba phambili we-voltage yesango elingumqansa wengezwa esangweni G kanye ne-emitter E phakathi kwesango, ukuze uvule ngokushesha ukuze ufinyelele isikhathi esifushane kakhulu sokunciphisa ukulahlekelwa kokuvula. Ekuvaleni kwe-IGBT, isekethe yedrayivu yesango kufanele inikeze unqenqema lokufika lwe-IGBT luyivoltheji yokuvala engumqansa kakhulu, futhi esangweni le-IGBT G kanye ne-emitter E phakathi kwe-voltage efanele ehlehlayo yokuchema, ukuze ukuvala shaqa okusheshayo kwe-IGBT, kufinyeze isikhathi sokuvala, kunciphise ukulahlekelwa ukuvala shaqa.

(2) Ngemva kokwenziwa kwe-IGBT, i-voltage yedrayivu kanye namanje okuhlinzekwa yisekethe yedrayivu yesango kufanele kube i-amplitude eyanele ye-voltage yedrayivu ye-IGBT kanye neyamanje, ukuze ukuphuma kwamandla e-IGBT kuhlale kusesimweni sokugcwala. Ukulayisha ngokweqile kwesikhashana, amandla okushayela ahlinzekwa yisekethe yedrayivu yesango kufanele abe ngokwanele ukuze kuqinisekiswe ukuthi i-IGBT ayiphumi esifundeni sokugcwala kanye nomonakalo.

(3) Isifunda sedrayivu yesango le-IGBT kufanele sinikeze i-IGBT i-positive drive voltage ukuze ithathe inani elifanele, ikakhulukazi enqubweni yokusebenza yesiyingi esifushane yezinto zokusebenza ezisetshenziswa ku-IGBT, i-voltage yedrayivu eqondile kufanele ikhethwe enanini elincane elidingekayo. Ukushintsha ukusetshenziswa kwamandla wesango le-IGBT kufanele kube ngu-10V ~ 15V ukuze kube ngcono kakhulu.

(4) Inqubo yokuvala shaqa ye-IGBT, i-voltage yokuchema engemihle esetshenziswa phakathi kwesango - i-emitter ihambisana nokuvala shaqa okusheshayo kwe-IGBT, kodwa akufanele ithathwe inkulu kakhulu, ithatha evamile -2V kuya ku- -10V.

(5) endabeni yemithwalo emikhulu ye-inductive, ukushintsha okusheshayo kuyingozi, imithwalo emikhulu ye-inductive ku-IGBT yokuvula nokucisha ngokushesha, izokhiqiza i-high-frequency kanye ne-amplitude ephezulu kanye nobubanzi obuncane be-spike voltage Ldi / dt , i-spike akulula ukumunca, kulula ukwenza umonakalo wedivayisi.

(6) Njengoba i-IGBT isetshenziswa ezindaweni ezinama-voltage aphezulu, ngakho-ke isifunda sokushayela kufanele sibe nayo yonke isifunda sokulawula emandleni okuzihlukanisa kakhulu, ukusetshenziswa okuvamile kokuhlukaniswa kwe-high-speed optical coupling noma ukuhlukaniswa kwe-transformer coupling.

Shayela isimo sesekhethi

Ngokuthuthuka kobuchwepheshe obuhlanganisiwe, isekethe yamanje ye-IGBT yesango lokushayela ilawulwa kakhulu ngama-chips ahlanganisiwe. Imodi yokulawula iseyizinhlobo ezintathu:

(1) uhlobo lokucupha oluqondile akukho ukuhlukaniswa kukagesi phakathi kokokufaka namasignali okukhiphayo.

(2) i-transformer isolation drive phakathi kwamasignali okufakwayo nokuphumayo usebenzisa i-pulse transformer isolation, i-isolation voltage level ifika ku-4000V.

Kunezindlela ezi-3 kanje

Indlela ye-Passive: ukukhishwa kwe-transformer yesibili kusetshenziselwa ukushayela ngokuqondile i-IGBT, ngenxa yemikhawulo yokulinganisa kwe-volt-second, kusebenza kuphela ezindaweni lapho umjikelezo wemisebenzi ungashintshi kakhulu.

Indlela esebenzayo: i-transformer inikeza kuphela amasignali angawodwa, kumjikelezo we-plastic amplifier wesibili ukushayela i-IGBT, i-drive waveform ingcono, kodwa isidingo sokuhlinzeka ngamandla asizayo ahlukene.

Indlela yokuzihlinzekela: i-pulse transformer isetshenziselwa ukudlulisa kokubili amandla okushayela kanye nokushintshwa kwemvamisa ephezulu kanye nobuchwepheshe bokwehlisa izinga lokudlulisa amasiginali anengqondo, ihlukaniswe ngendlela yokuzinikezela yohlobo lwe-modulation kanye nobuchwepheshe bokwabelana ngesikhathi, lapho ukuguquguquka - thayipha amandla okuzihlinzekela ebhulohweni elilungisa kabusha ukuze ukhiqize amandla adingekayo, i-high-frequency modulation kanye nobuchwepheshe bokwehlisa amandla ukuze kudluliselwe ingqondo izimpawu.

3. Ukuthintana nomehluko phakathi kwe-thyristor ne-IGBT drive

I-Thyristor ne-IGBT drive circuit inomehluko phakathi kwesikhungo esifanayo. Okokuqala, izifunda ezimbili zokushayela ziyadingeka ukuze zihlukanise idivayisi yokushintsha kanye nesifunda sokulawula kusuka komunye nomunye, ukuze ugweme ama-circuits ane-voltage ephezulu abe nomthelela kumjikelezo wokulawula. Khona-ke, kokubili kusetshenziswe kusignali yesango lokushayela ukuze kuqalise idivayisi yokushintsha. Umehluko wukuthi idrayivu ye-thyristor idinga isignali yamanje, kuyilapho i-IGBT idinga isignali ye-voltage. Ngemuva kokuguqulwa kwedivayisi yokuguqula, isango le-thyristor lilahlekelwe ukulawula ukusetshenziswa kwe-thyristor, uma ufuna ukuvala i-thyristor, ama-terminals e-thyristor kufanele afakwe ku-voltage reverse; futhi ukuvala shaqa kwe-IGBT kudinga kuphela ukwengezwa esangweni le-voltage yokushayela engalungile, ukuze kuvalwe i-IGBT.

4. Isiphetho

Leli phepha lihlukaniswe ikakhulukazi izingxenye ezimbili zokulandisa, ingxenye yokuqala yesicelo sesifunda se-thyristor drive sokumisa ukulandisa, ukwakheka kwesekethe yedrayivu ehambisanayo, futhi ukwakheka kwesekethe kusetshenziselwa isekethe ye-thyristor esebenzayo, ngokulingisa. kanye nokuhlola ukufakazela ukuba nokwenzeka kwesekethe yedrayivu, inqubo yokuhlola okuhlangatshezwane nayo ekuhlaziyeni izinkinga ezimile futhi zasingathwa. Ingxenye yesibili yengxoxo eyinhloko nge-IGBT ngesicelo sesekethe yedrayivu, futhi ngalesi sisekelo ukuqhubeka nokwethula isekethe yedrayivu esetshenziswa kakhulu ye-IGBT, kanye nesekethe enkulu ye-optocoupler isolation drive ukumisa ukulingisa nokuhlola, ukufakazela ukubakhona kwesekethe yedrayivu.