Uthini umgaqo wesekethe yokuqhuba ye-MOSFET yamandla aphezulu?

I-MOSFET enamandla amakhulu, ukusetyenziswa kweesekethe ezahlukeneyo zokuqhuba kuya kufumana iimpawu ezahlukeneyo zokutshintsha. Ukusetyenziswa kokusebenza kakuhle kwesekethe yokuqhuba kunokwenza isixhobo sokutshintsha amandla sisebenze kwimeko efanelekileyo yokutshintsha, ngelixa unciphisa ixesha lokutshintsha, ukunciphisa ilahleko yokutshintsha, ukufakwa kokusebenza kakuhle, ukuthembeka kunye nokhuseleko kubaluleke kakhulu. Ngoko ke, iingenelo kunye nokungonakali kwesekethe yokuqhuba ichaphazela ngokuthe ngqo ukusebenza kwesekethe ephambili, ukulungelelaniswa koyilo lwesekethe yokuqhubela phambili kubaluleke kakhulu. I-Thyristor ubungakanani obuncinci, ubunzima bokukhanya, ukusebenza kakuhle, ubomi obude, kulula ukuyisebenzisa, inokumisa ngokulula i-rectifier kunye ne-inverter, kwaye ayikwazi ukuguqula isakhiwo sesiphaluka phantsi kwesiseko sokutshintsha ubungakanani be-rectifier okanye i-inverter yangoku.IGBT yimbumba edibeneyo. isixhobo seI-MOSFETkunye ne-GTR, eneempawu zesantya sokutshintsha ngokukhawuleza, ukuzinza okuhle kwe-thermal, amandla amancinci okuqhuba kunye nesekethe ye-drive elula, kwaye ineenzuzo zokuhla kwamandla ombane omncinci kwi-state, i-voltage ephezulu yokumelana kunye nokwamkelwa okuphezulu. I-IGBT njengesixhobo esiqhelekileyo sokukhupha amandla, ngakumbi kwiindawo eziphezulu zamandla, isetyenziswe ngokuqhelekileyo kwiindidi ezahlukeneyo.

Isekethe efanelekileyo yokuqhuba izixhobo zokutshintsha amandla aphezulu eMOSFET kufuneka ihlangabezane nezi mfuno zilandelayo:

(1) Xa ityhubhu yokutshintsha amandla ivuliwe, isiphaluka sokuqhuba sinokubonelela ngokunyuka kwesiseko sangoku, ukwenzela ukuba kubekho amandla okuqhuba okwaneleyo xa ivuliwe, ngaloo ndlela inciphisa ukulahleka kokuvula.

(2) Ngexesha lokuqhuba ityhubhu yokutshintsha, umbane wesiseko obonelelwa yisekethe yomqhubi we-MOSFET unokuqinisekisa ukuba ityhubhu yamandla ikwimeko yokuqhubela phambili egcweleyo phantsi kwayo nayiphi na imeko yomthwalo, iqinisekisa ilahleko yokuthelekisa ephantsi. Ukuze kuncitshiswe ixesha lokugcinwa, isixhobo kufuneka sibe kwindawo ebalulekileyo yokugcwala ngaphambi kokuvala.

(3) ukuvala, isiphaluka sokuqhuba kufuneka sinikeze isiseko esaneleyo sokubuyela umva ngokukhawuleza ukukhupha abathwali abaseleyo kwingingqi yesiseko ukunciphisa ixesha lokugcina; kwaye yongeza i-voltage ye-reverse bias cutoff, ukwenzela ukuba umqokeleli wangoku awe ngokukhawuleza ukunciphisa ixesha lokufika. Ngokuqinisekileyo, ukucinywa kwe-thyristor kusekho ubukhulu becala ngokuhla kwe-anode voltage ukugqiba ukuvala.

Okwangoku, i-thyristor iqhube ngenani elithelekisekayo nje nge-transformer okanye i-optocoupler yodwa yokwahlula isiphelo sombane ophantsi kunye nesiphelo sombane ophezulu, kwaye emva koko ngesekethe yokuguqula ukuqhuba i-thyristor conduction. Kwi-IGBT yokusetyenziswa kwangoku kweemodyuli ezininzi ze-IGBT zokuqhuba, kodwa kwakhona i-IGBT edibeneyo, ukugcinwa kwenkqubo, ukuzixilonga kunye nezinye iimodyuli ezisebenzayo ze-IPM.

Kweli phepha, kuba thyristor sisebenzisa, ukuyila isiphaluka zovavanyo drive, kwaye uyeke uvavanyo lokwenyani ukubonisa ukuba unako ukuqhuba thyristor. Ngokuphathelele ukuqhuba kwe-IGBT, eli phepha lazisa ubukhulu becala iintlobo eziphambili zangoku ze-IGBT drive, kunye nesekethe yazo ehambelanayo yokuqhuba, kunye neyona ndlela iqhelekileyo isetyenziswa kwi-optocoupler isolation drive ukumisa uvavanyo lokulinganisa.

2. Isifundo sesekethe ye-Thyristor ngokubanzi iimeko zokusebenza ze-thyristor zezi:

(1) i-thyristor iyayamkela i-voltage ye-anode ebuyela umva, kungakhathaliseki ukuba isango livuma ukuba luhlobo luni lombane, i-thyristor ikwimo evaliweyo.

(2) I-Thyristor iyamkela i-voltage ye-anode yangaphambili, kuphela kwimeko yesango yamkele i-voltage echanekileyo i-thyristor ivuliwe.

3 (4) i-thyristor kwimeko yokuqhuba, xa i-voltage yesiphaluka engundoqo (okanye yangoku) iyancipha ukuya kufuphi ne-zero, i-thyristor shutdown. Sikhetha i-thyristor yi-TYN1025, i-voltage yayo yokumelana yi-600V ukuya kwi-1000V, ngoku ukuya kwi-25A. ifuna i-gate drive voltage yi-10V ukuya kwi-20V, i-drive current yi-4mA ukuya kwi-40mA. kunye nokugcinwa kwayo ngoku yi-50mA, i-injini yangoku yi-90mA. nokuba yi-DSP okanye i-CPLD ibangela i-amplitude yomqondiso nje ngokuba ngu-5V. Okokuqala, ngokude nje i-amplitude ye-5V kwi-24V, kwaye emva koko nge-2: 1 i-isolation transformer ukuguqula isignali ye-24V ye-trigger ibe ngumqondiso we-12V we-trigger, ngelixa ugqibezela umsebenzi we-voltage ephezulu kunye nesezantsi.

Uyilo lwesekethe yovavanyo kunye nohlalutyo

Okokuqala, i-boost circuit, ngenxa yesekethe ye-transformer yodwa kwinqanaba elingasemva leI-MOSFETisixhobo sidinga i-15V yesiginali ye-trigger, ngoko ke imfuno yokuqala ye-amplitude ye-5V yesiginali ye-trigger ibe yi-15V yesiginali ye-trigger, nge-MC14504 5V isiginali, iguqulelwe kwisiginali ye-15V, kwaye emva koko nge-CD4050 kwimveliso ye-15V yokubunjwa kwesiginali ye-drive, itshaneli 2. iqhagamshelwe kwisiginali yegalelo le-5V, ishaneli ye-1 iqhagamshelwe kwimveliso yeChannel 2 iqhagamshelwe kwisiginali yegalelo le-5V, itshaneli. I-1 ixhunywe kwimveliso ye-15V yesignali yokuqalisa.

Inxalenye yesibini yi-local transformer circuit, owona msebenzi uphambili wesekethe ngulo: i-15V yesiginali ye-trigger, iguqulelwe kwisignali ye-12V yokuqalisa umva we-thyristor conduction, kunye nokwenza umqondiso we-15V kunye nomgama phakathi komva. iqonga.

Umgaqo wokusebenza wesekethe yile: ngenxa yeI-MOSFETI-IRF640 i-voltage ye-drive ye-15V, ngoko, okokuqala, kwi-J1 ukufikelela kwi-15V yesikwele somqondiso we-square wave, ngokusebenzisa i-resistor R4 eqhagamshelwe kwi-regulator 1N4746, ukuze i-voltage ye-trigger izinzile, kodwa kunye nokwenza i-voltage ye-trigger ayikho phezulu kakhulu. , yatshisa i-MOSFET, kwaye emva koko kwi-MOSFET IRF640 (enyanisweni, le yityhubhu yokutshintsha, ulawulo lomva wesiphelo sokuvula kunye ukuvala umva ekupheleni kokuvula kunye nokucima), emva kokulawula umjikelo womsebenzi wesiginali yokuqhuba, ukuze ukwazi ukulawula ixesha lokuvula kunye nokucima i-MOSFET. Xa i-MOSFET ivuliwe, ilingana nomhlaba wayo we-D-pole, ivaliwe xa ivuliwe, emva kwesekethe ye-back-end elingana ne-24 V. Kwaye i-transformer idlula utshintsho lwe-voltage ukwenza isiphelo esilungileyo se-12 V yesignali yokuphuma. . Isiphelo esilungileyo se-transformer sixhunywe kwibhuloho yokulungisa, kwaye emva koko isignali ye-12V iphuma kwi-Connector X1.

Iingxaki ezifunyenwe ngexesha lovavanyo

Okokuqala, xa umbane uvuliwe, i-fuse ngokukhawuleza yavuthela, kwaye kamva xa kuhlolwa isiphaluka, kwafumanisa ukuba kukho ingxaki ngoyilo lwesiphaluka sokuqala. Ekuqaleni, ukuze kuphuculwe isiphumo sokuphuma kwetyhubhu yayo yokutshintsha, i-24V yomhlaba kunye ne-15V yokwahlulwa komhlaba, eyenza i-pali ye-MOSFET yesango elilingana nomva we-S pole inqunyanyiswe, okukhokelela ekuvuseni okungeyonyani. Unyango kukudibanisa umhlaba we-24V kunye ne-15V kunye, kwaye kwakhona ukumisa umfuniselo, isekethe isebenza ngokuqhelekileyo. Uqhagamshelo lwesekethe luqhelekile, kodwa xa uthatha inxaxheba kwisiginali yokuqhuba, ubushushu beMOSFET, kunye nesiginali yedrive kangangexesha elithile, ifuse iyavuthelwa, emva koko yongeze isiginali yokuqhuba, ifuse ivuthelwe ngokuthe ngqo. Jonga isekethe ifumanise ukuba umjikelo wenqanaba eliphezulu lomsebenzi wesiginali yedrive inkulu kakhulu, okukhokelela ekubeni ixesha lokuvula i-MOSFET lide kakhulu. Uyilo lwale sekethe lwenza xa i-MOSFET ivuliwe, i-24V yongezwa ngokuthe ngqo kwiziphelo ze-MOSFET, kwaye ayizange yongeze isichasi somda wangoku, ukuba ixesha lide kakhulu ukwenza i-current ikhulu kakhulu, umonakalo we-MOSFET, imfuno yokulawula umjikelo womsebenzi wesiginali ayinakuba nkulu kakhulu, ngokuqhelekileyo kwi-10% ukuya kwi-20% okanye kunjalo.

2.3 Ukuqinisekiswa kwesekethe yokuqhuba

Ukuze uqinisekise ukuba kunokwenzeka isekethe drive, sisebenzisa ngayo ukuqhuba isekethe thyristor eqhagamshelwe kuthotho kunye nomnye, i thyristor kuthotho kunye nomnye emva koko anti-parallel, ukufikelela kwisekethe kunye reactance inductive, unikezelo lwamandla. ngumthombo wombane we-380V AC.

I-MOSFET kule sekethe, i-thyristor Q2, i-Q8 i-trigger signal ngokusebenzisa i-G11 kunye ne-G12 yokufikelela, ngelixa i-Q5, i-Q11 iqalisa i-signal ngokusebenzisa i-G21, i-G22 yokufikelela. Ngaphambi kokuba umqondiso we-drive ufunyenwe kwinqanaba lesango le-thyristor, ukwenzela ukuba kuphuculwe amandla okuthintela ukuphazamiseka kwe-thyristor, isango le-thyristor lixhunywe kwi-resistor kunye ne-capacitor. Le sekethi iqhagamshelwe kwi-inductor ize ifakwe kwisekethe ephambili. Emva kokulawula i-angle conduction ye-thyristor ukulawula i-inductor enkulu kwixesha lesekethe eliphambili, iisekethe eziphezulu kunye nezisezantsi ze-angle yesigaba se-trigger umahluko wesignali yesiqingatha somjikelo, i-G11 ephezulu kunye ne-G12 ngumqondiso we-trigger yonke indlela. ngokusebenzisa i-drive circuit ye-front stage ye-transformer yodwa ihlukaniswe enye kwenye, i-G21 ephantsi kunye ne-G22 nayo yodwa kwindlela efanayo yomqondiso. Iimpawu ezimbini ze-trigger zibangela i-anti-parallel thyristor circuit conduction positive and negative conduction, ngaphezu kwetshaneli ye-1 idityaniswe kwi-voltage yesiphaluka se-thyristor, kwi-conduction ye-thyristor iba yi-0, kunye ne-2, i-3 itshaneli idityaniswe kwisekethe ye-thyristor phezulu naphantsi. imiqondiso yokuqalisa indlela, umjelo we-4 ulinganiswa nokuhamba kwayo yonke i-thyristor yangoku.

I-2 itshaneli ilinganisa umqondiso we-positive trigger, eqhutywe ngaphezu kwe-thyristor conduction, okwangoku ilungile; Ishaneli ye-3 ilinganisa umqondiso we-reverse trigger, ibangela isiphaluka esisezantsi se-thyristor conduction, i-current is negative.

3.IGBT drive circuit yesemina IGBT drive circuit inezicelo ezininzi ezizodwa, ezishwankathelweyo:

(1) ukuqhuba isantya sokunyuka kunye nokuwa kwe-voltage pulse kufuneka ibe nkulu ngokwaneleyo. Ukuvula i-igbt, umgca ohamba phambili we-voltage yesango elinqambileyo yongezwa kwisango G kunye ne-emitter E phakathi kwesango, ukuze ivule ngokukhawuleza ukufikelela kwixesha elifutshane kakhulu lokunciphisa ilahleko. Kwi-IGBT yokuvala, i-gate drive circuit kufuneka ibonelele i-IGBT edge yokumisa i-voltage yokucima kakhulu, kunye nesango le-IGBT G kunye ne-emitter E phakathi kwe-voltage efanelekileyo ye-bias, ukuze i-IGBT ivale ngokukhawuleza, inciphise ixesha lokuvala, ukunciphisa ilahleko yokuvala.

(2) Emva kwe-IGBT conduction, i-voltage ye-drive kunye ne-current enikezelwa yi-gate drive circuit ifanele ibe yi-amplitude eyaneleyo kwi-voltage ye-IGBT ye-drive kunye ne-current, ukwenzela ukuba ukuphuma kwamandla e-IGBT kuhlale kukwimeko egcweleyo. Ukugqithiswa okugqithisiweyo, amandla okuqhuba abonelelwa yisekethe ye-gate drive kufuneka abe ngokwaneleyo ukuqinisekisa ukuba i-IGBT ayiphumi kwindawo yokuzalisa kunye nomonakalo.

(3) I-IGBT isango lomqhubi wesiphaluka kufuneka ibonelele nge-IGBT i-voltage esebenzayo yokuthatha ixabiso elifanelekileyo, ngokukodwa kwinkqubo yokusebenza ye-short-circuit yezixhobo ezisetyenziswe kwi-IGBT, i-voltage ye-positive drive kufuneka ikhethwe kwixabiso elincinci elifunekayo. Ukutshintshwa kwesicelo sombane wesango le-IGBT kufuneka ibe yi-10V ~ 15V eyona nto ingcono.

(4) Inkqubo yokuvala i-IGBT, i-voltage ye-bias negative isetyenziswe phakathi kwesango - i-emitter ilungele ukuvalwa ngokukhawuleza kwe-IGBT, kodwa akufanele ithathwe ikhulu kakhulu, ithatha eqhelekileyo -2V ukuya -10V.

(5) kwimeko yemithwalo emikhulu yokuhambisa, ukutshintshela ngokukhawuleza kuyingozi, imithwalo emikhulu yokunciphisa i-IGBT yokuvula ngokukhawuleza kunye nokucima, iya kuvelisa i-high-frequency kunye ne-amplitude ephezulu kunye nobubanzi obumxinwa bombane we-spike Ldi / dt. , i-spike ayilula ukufunxa, kulula ukwenza umonakalo wesixhobo.

(6) Njengoko i-IGBT isetyenziselwa kwiindawo eziphezulu ze-voltage, ngoko ke isekethe ye-drive kufuneka ibe nayo yonke isiphaluka solawulo kwikhono lokuzihlukanisa kakhulu, ukusetyenziswa okuqhelekileyo kwe-high-speed optical coupling isolation okanye i-transformer coupling isolation.

Qhuba ubume besekethe

Ngophuhliso lwetekhnoloji ehlanganisiweyo, isekethe yangoku yesango le-IGBT yesango ilawulwa ikakhulu ngamatshiphusi adibeneyo. Imo yolawulo isezintlobo ezintathu ikakhulu:

(1) uhlobo olubangela ngokuthe ngqo akukho ukwahlulwa kombane phakathi kwegalelo kunye neempawu eziphumayo.

(2) i-transformer yodwa i-drive phakathi kwegalelo kunye nemiqondiso yemveliso usebenzisa i-pulse transformer isolation, i-voltage yokuzimela yodwa ukuya kwi-4000V.

Kukho iindlela ezi-3 ngolu hlobo lulandelayo

Indlela ye-Passive: i-output ye-transformer yesibini isetyenziselwa ukuqhuba ngokuthe ngqo i-IGBT, ngenxa yokulinganiselwa kwe-volt-second equalization, isebenza kuphela kwiindawo apho umjikelezo womsebenzi ungatshintshi kakhulu.

Indlela esebenzayo: i-transformer ibonelela kuphela ngemiqondiso esecaleni, kwisekethe yesibini ye-amplifier yeplastiki ukuqhuba i-IGBT, i-wave wave ingcono, kodwa imfuno yokubonelela ngamandla ancedisayo ahlukeneyo.

Indlela yokubonelela ngokuzimela: i-pulse transformer isetyenziselwa ukuhambisa zombini amandla okuqhuba kunye ne-high-frequency modulation kunye ne-demodulation yetekhnoloji yokuhanjiswa kweempawu ezinengqondo, yahlulwe ngendlela yokubonelela ngemodyuli kunye nexesha lokwabelana ngetekhnoloji yokuzinikezela, apho ukumodareyitha. -chwetheza amandla okuzinikezela kwibhulorho yokulungisa ukuvelisa umbane ofunekayo, ukumodareyitha okuphezulu okujikelezayo kunye netekhnoloji yokunciphisa ukuhambisa ingqiqo iimpawu.

3. Uqhagamshelwano kunye nokwahlukana phakathi kwe-thyristor kunye ne-IGBT drive

I-Thyristor kunye ne-IGBT drive circuit inomahluko phakathi kweziko elifanayo. Okokuqala, iisekethe ezimbini zokuqhuba zifuneka ukuba zihlukanise isixhobo sokutshintsha kunye nesiphaluka solawulo ukusuka komnye nomnye, ukwenzela ukuba ugweme iisekethe eziphezulu ze-voltage zinempembelelo kwisiphaluka sokulawula. Emva koko, zombini zisetyenziswe kwisiginali yesango lokuqhuba ukuqalisa isixhobo sokutshintsha. Umahluko kukuba i-thyristor drive idinga isignali yangoku, ngelixa i-IGBT idinga uphawu lombane. Emva kokutshintshwa kwesixhobo sokutshintsha, isango le-thyristor lilahlekelwe ulawulo lokusetyenziswa kwe-thyristor, ukuba ufuna ukuvala i-thyristor, i-terminals ye-thyristor kufuneka yongezwe kwi-voltage reverse; kunye nokuvalwa kwe-IGBT kufuneka kufakwe kuphela kwisango le-voltage ye-negative drive, ukuvala i-IGBT.

4. Isiphelo

Eli phepha ubukhulu becala lahlulwe laba ngamacandelo amabini okubalisa, inxalenye yokuqala yesicelo sesekethe ye-thyristor drive ukumisa ibali, uyilo lwesekethe yesekethe ehambelanayo, kunye noyilo lwesekethe lusetyenziswa kwisekethe ye-thyristor ebonakalayo, ngokulinganisa. kunye novavanyo lokuqinisekisa ukuba nokwenzeka kwesekethe yokuqhuba, inkqubo yovavanyo ekuhlangatyenwe nayo kuhlalutyo lweengxaki yayeka kwaze kwajongwana nayo. Inxalenye yesibini yengxoxo ephambili kwi-IGBT ngesicelo sesekethe yokuqhuba, kwaye ngesi siseko ukwazisa ngakumbi isekethe ye-IGBT esetyenziswa ngoku exhaphakileyo, kunye nesekethe ephambili ye-optocoupler isolation drive ukumisa ukulinganisa kunye nokulinga, ukubonisa ukuba nokwenzeka kwesekethe yokuqhuba.