Yiziphi izimbangela zokushisa ku-MOSFET ye-inverter?

I-inverterAma-MOSFETsebenza esimweni sokushintsha futhi lamanje eligeleza ngamashubhu liphezulu kakhulu. Uma ishubhu ingakhethiwe kahle, i-voltage amplitude yokushayela ayinkulu ngokwanele noma ukuchithwa kokushisa kwesekethe akukuhle, kungabangela i-MOSFET ukushisa.

 

1, inverter MOSFET Ukushisa kuyinto sina, kufanele sinake ukukhethwa MOSFET

I-MOSFET ku-inverter esimweni sokushintsha, ngokuvamile idinga i-drain current yayo ibe nkulu ngangokunokwenzeka, ukumelana nokumelana kube kuncane ngangokunokwenzeka, okunganciphisa ukwehla kwe-saturation voltage yeshubhu, ngaleyo ndlela kunciphise ishubhu kusukela ekusetshenzisweni, kunciphise ukushisa.

Hlola imanuwali ye-MOSFET, sizothola ukuthi lapho ukuphakama kwevelu yokumelana ne-voltage ye-MOSFET, iba nkulu ukumelana kwayo, nalawo anevelu ye-voltage edonsa kanzima futhi ephansi yepayipi, ukumelana kwayo ngokuvamile kungaphansi kwamashumi amamiliyoni.

Uma sicabanga umthamo wamanje we-5A, sikhetha i-inverter evame ukusetshenziswa i-MOSFET RU75N08R kanye nevelu yokumelana ne-voltage engu-500V 840 ingaba, i-drain current yabo iku-5A noma ngaphezulu, kodwa ukumelana kwamashubhu amabili kuhlukile, shayela okwamanje okufanayo. , umehluko wabo wokushisa mkhulu kakhulu. I-75N08R on-resistance ingu-0.008Ω kuphela, kuyilapho ukumelana kwe-840 kungu-0.85Ω, lapho umthwalo wamanje ogeleza ngeshubhu kungu-5A, ukwehla kwe-voltage engu-75N08R kungu-0.04V kuphela, ngalesi sikhathi, ukusetshenziswa kweshubhu le-MOSFET kungu- i-0.2W kuphela, kuyilapho ukwehla kwamandla ka-840 tube kungaba kufika ku-4.25W, ukusetshenziswa kweshubhu kuphezulu njengo-21.25W. Kulokhu kungabonakala, okuncane ukumelana nokumelana kwe-MOSFET ye-inverter kungcono, ukumelana kwe-tube kukhulu, ukusetshenziswa kweshubhu ngaphansi kwamanje okuphezulu Ukumelana nokumelana kwe-MOSFET ye-inverter kuncane. ngangokunokwenzeka.

 

2, isifunda sokushayela se-voltage amplitude asisikhulu ngokwanele

I-MOSFET iyithuluzi lokulawula i-voltage, uma ufuna ukunciphisa ukusetshenziswa kweshubhu, ukunciphisa ukushisa,I-MOSFETisango lokushayela i-voltage amplitude kufanele libe likhulu ngokwanele ukushayela unqenqema lwe-pulse ukuze lube umqansa futhi luqonde, unganciphisa ukwehla kwamandla kagesi, unciphise ukusetshenziswa kweshubhu.

 

3, Ukushisa kwe-MOSFET akusona isizathu esihle

I-InverterI-MOSFETUkushisa kuyingozi. Njengoba i-inverter MOSFET ukusetshenziswa kwamandla kukukhulu, umsebenzi ngokuvamile udinga indawo enkulu eyanele yangaphandle ye-heatsink, futhi i-heatsink yangaphandle kanye ne-MOSFET ngokwayo phakathi kwe-heatsink kufanele isondelene nayo (ngokuvamile iyadingeka ukuthi ihlanganiswe ngamafutha abicah conductive thermally conductive. ), uma i-heatsink yangaphandle iyingcosana, noma ukuthintana ne-heatsink ye-MOSFET uqobo kungasondeli ngokwanele, kungaholela ekushisiseni kweshubhu.

 

Inverter MOSFET Ukushisa sina kunezizathu ezine isifinyezo.

Ukushisa okuncane kwe-MOSFET kuyinto evamile, kodwa ukushisa okungathi sína, okuholela epayipini kuyashiswa, kunezizathu ezine ezilandelayo:

 

1, inkinga yokuklama kwesifunda

Vumela i-MOSFET isebenze esimweni sokusebenza esilandelanayo, esikhundleni sokushintshwa kwesiyingi. Kuphinde kube ngesinye sezimbangela zokushisisa kweMOSFET. Uma i-N-MOS yenza ukushintsha, i-voltage yeleveli ye-G kufanele ibe ngama-V ambalwa ngaphezu kwamandla ukuze ivuleke ngokugcwele, kuyilapho i-P-MOS iphambene. Ayivuleki ngokuphelele futhi ukwehla kwe-voltage kukhulu kakhulu okuholela ekusetshenzisweni kwamandla, i-impedance ye-DC efanayo inkulu, ukwehla kwe-voltage kuyanda, ngakho-ke u-U * nami ngiyakhuphuka, ukulahlekelwa kusho ukushisa. Leli iphutha eligwenywe kakhulu ekwakhiweni kwesekethe.

 

2, imvamisa ephezulu kakhulu

Isizathu esiyinhloko ukuthi ngezinye izikhathi ukuphishekela ngokweqile kwevolumu, okuholela ekukhuleni kwemvamisa, ukulahlekelwa kwe-MOSFET kukhulu, ngakho ukushisa nakho kuyanda.

 

3, ukuklama okwanele okushisayo

Uma i-current iphezulu kakhulu, inani lamanje le-MOSFET, ngokuvamile lidinga ukulahlwa kokushisa okuhle ukuze kufinyelelwe. Ngakho-ke i-ID ingaphansi komkhawulo wamanje, ingase futhi ishise kabi, idinge usinki wokushisa owanele.

 

4, ukukhethwa kwe-MOSFET akulungile

Ukwahlulela okungalungile kwamandla, ukumelana kwangaphakathi kwe-MOSFET akucatshangelwa ngokugcwele, okuholela ekwandeni kokuphazamiseka kokushintsha.