Embonini yamandla nogesi, iziguquli zefrikhwensi zisetshenziswa kakhulu ukongiwa kwamandla kanye nokwenza ngcono izinqubo zokukhiqiza. Njengemishini yokonga amandla nesivinini sokulawula amamotho, asetshenziswa kabanzi kwezensimbi, amandla, amanzi, uphethiloli, amakhemikhali, amalahle neminye imikhakha. Ingqikithi yeyunithi yempendulo yamandla yesiguquli sefrikhwensi ingukuguqulwa okusebenzayo. Indlela yokusebenzisa yeyunithi yempendulo yamandla yesiguquli sefrikhwensi evamile iwukuphakela amandla avuselelwe kugridi ngama-anti parallel ama-inverter ezigaba ezintathu kusilungisi esingalawuleki sesiteji esingaphambili sesiguquli sefrikhwensi evamile. Isekhethi eyinhloko yeyunithi yempendulo yamandla ikakhulukazi yakhiwe ibhuloho eliguquguqukayo elihlanganisa ama-thyristors, ama-IGBT, amamojula e-IPM, namanye amasekhethi aseduze.
Ukuphela kokuphumayo kwebhuloho le-inverter kuxhunywe kumatheminali okokufaka u-R, S, kanye no-T wesiguquli semvamisa ngokusebenzisa ama-reactor amathathu okuklinywa, futhi isiphetho sokufakwayo sixhunywe ku-terminal evumayo yohlangothi lwe-DC lwesiguquli semvamisa yendawo yonke ngokusebenzisa i-isolation diode ukuze kuqinisekiswe ukugeleza kwamandla okungafani nokuqondisa ngakunye "i-frequency converter esebenzayo yegridi yebhuloho". Umsebenzi we-reactor yokuminyanisa ukulinganisa umehluko we-voltage, umkhawulo wamanje, nesihlungi, okudlala indima ebalulekile empendulweni yamandla okuvuselela kugridi yamandla.
Inqubo yokusebenza yesistimu iwukuthi: lapho i-motor isebenza, idivayisi ye-inverter esebenzayo ayisebenzi, futhi amashubhu wokushintsha inverter avinjelwe futhi asesimweni esivaliwe; Lapho injini isesimweni sokukhiqiza amandla kabusha, amandla abuyiselwa kugridi yinjini, futhi umshini wokushintshashintsha osebenzayo udinga ukuqaliswa ukusebenza.
Ukwenziwa kusebenze kwedivayisi ye-inverter esebenzayo phakathi nempendulo yamandla kulawulwa ubukhulu be-voltage eseceleni ye-DC Ud yesiguquli sefrikhwensi. Isisekelo siwukuthi lapho injini isesimweni sikagesi, i-voltage eseceleni ye-DC yesiguquli semvamisa ihlala injalo. Lapho injini isesimweni esikhiqiza amabhuleki, amandla okuvuselela emoto ye-AC ashaja i-capacitor yokugcina amandla phakathi kwesixhumanisi se-DC se-frequency converter, okubangela ukuba i-voltage yebhasi ye-DC inyuke. Uma nje ubukhulu be-Ud butholwa, isimo semoto singanqunywa, futhi idivayisi ye-inverter esebenzayo ingalawulwa ukuze kuzuzwe impendulo yamandla.
Lapho amandla ebuyiselwa ohlangothini lwe-DC ngenjini, okubangela ugesi webhasi le-DC ukuba udlule ugesi ophakeme womugqa wegridi yamandla, ibhuloho elilungisa kabusha le-universal frequency converter lizovala ngenxa ye-voltage ehlehlayo; Lapho i-voltage yebhasi ye-DC iqhubeka nokukhuphuka futhi idlula i-voltage esebenzayo ye-inverter esebenzayo yokuqala, i-inverter iqala ukusebenza, ibuyisela amandla kugridi ukusuka ohlangothini lwe-DC; Lapho i-voltage yebhasi ye-DC yehla ku-voltage yokusebenza ye-inverter, i-inverter esebenzayo ivaliwe.
Ngokusebenzisa i-inverter esebenzayo ukuze uphendule amandla avuselelwayo akhiqizwa ngesikhathi sokuncipha kwemoto kanye nokubhuleka kugridi yamandla, isiguquli sefrikhwensi yendawo yonke singanqoba ukusebenza kahle okuphansi nobunzima ekuhlangabezaneni nezidingo zokubhuleka ngokushesha kanye nokuzungeza okuya phambili/okuhlehlisayo okubangelwa ukusetshenziswa okujwayelekile kwama-braking resistors, okuvumela isiguquli sefrikhwensi esisebenza emhlabeni wonke ukuthi sisebenze ngamaquadrants amane.
1) Uhlelo lokulawula impendulo yamandla
Uhlelo oluphelele lokulawula impendulo yamandla kufanele luhlangabezane nezimo zokulawula zesigaba, i-voltage, yamanje, njll., okudinga ukuthi inqubo yempendulo kufanele ivunyelaniswe nesigaba segridi, futhi idivayisi yokuguqula esebenzayo kufanele iqalwe kuphela lapho i-voltage yebhasi ye-DC idlula inani elithile; Isistimu kufanele ikwazi ukulawula ubukhulu bempendulo yamanje, ngaleyo ndlela ilawule i-torque yokubhuleka yemoto futhi izuze ukubhuleka okunembile.
2) Izinhlobo ezimbili zamayunithi wempendulo yamandla e-universal frequency converter
Ngaphambilini, isekethe eyinhloko yamayunithi empendulo yamandla iningi lakhiwe ama-thyristors nama-IGBT. Eminyakeni yakamuva, ezinye izinhlobo ezintsha zamayunithi empendulo yamandla nazo zisebenzise amamojula ahlakaniphile njenge-IPM ukwenza lula ukwakheka kwesistimu yamayunithi empendulo yamandla.
(1) Iyunithi yempendulo yamandla e-Thyristor:
Isekhethi eyinhloko yempendulo yamandla yenziwe ngamadivayisi e-thyristor, okubuye kube iyunithi yempendulo yamandla wangaphambi kwesikhathi. Ayisetshenziswa kuphela kuma-converter ama-frequency, kodwa futhi nasekubhulekeni kwamanye amasistimu okulawula isivinini abuyiselekayo e-DC.
① Dlulisela phambili isimo sokusebenza se-universal frequency converter: Uma injini ikusimo sikagesi, isilungisisi sesiguquli sefrikhwensi siyasebenza, kuyilapho idivayisi ye-thyristor eyunithi yempendulo yamandla ayicushiwe futhi isesimweni sokunqanyulwa, futhi isilungisi sisebenzela indlela eya phambili. Ingxenye ye-inverter elawulwayo ye-inverter ibangelwa ukusebenza, ingxenye engalawuleki yokulungiswa kabusha kwe-reverse isesimweni esinqunyiwe, futhi i-inverter isebenza phambili.
② Isimo sokusebenza esihlehliswayo se-universal frequency converter: Uma injini isesimweni sokukhiqiza, isilungisi sokuphinda siguqule imvamisa sisesimweni sokunqanyulwa, kanye namadivayisi we-thyristor kuyunithi yempendulo yamandla ayacushwa ukuthi asebenze. Ingxenye ye-inverter elawulekayo ye-inverter isacushiwe ukuthi isebenze, ingxenye engalawuleki yokulungiswa okuhlanekezelayo isesimweni sokusebenza, futhi i-inverter isebenza ngokuhlehla.
(2) Iyunithi yempendulo ye-IGBT yamandla:
Isekhethi eyinhloko yempendulo yamandla yenziwe ngamadivayisi e-IGBT, asetshenziswa kakhulu kuziguquli ezijwayelekile. I-freewheeling diode ehlanganiswe namadivayisi e-IGBT ayikwazi ukusetshenziswa njengethuluzi lokulungisa ngenxa yokukhawulelwa kwe-isolation diode exhunywe ohlangothini lwe-DC. Izindleko zayo kufanele zibe phezulu kuneyunithi yempendulo ye-thyristor energy.
① Isimo sokuqhubekela phambili sokusebenza kwesiguquli sefrikhwensi yendawo yonke: Uma injini isesimweni sikagesi, isilungisisi sesiguquli sefrikhwensi siyasebenza, kuyilapho idivayisi ye-IGBT eyunithi yempendulo yamandla ayicushiwe futhi isesimweni sokunqanyulwa, futhi isilungisi sisebenzela indlela eya phambili. Amadivayisi e-IGBT ku-inverter aculwa ukuthi asebenze, futhi ingxenye engalawulwa yokulungiswa okuhlanekezelayo isesimweni sokunqanyulwa, kuyilapho i-inverter isebenza phambili.
② Isimo sokusebenza esihlehliswayo se-universal frequency converter: Uma injini isesimweni sokukhiqiza, isilungisi kabusha sesiguquli sefrikhwensi sisesimweni sokunqanyulwa, futhi idivayisi ye-IGBT eyunithi yempendulo yamandla iqalwa ukuthi isebenze. Amadivayisi e-IGBT ku-inverter asacutshungulwa ukuthi asebenze, futhi ingxenye engalawuleki yokuhlehlisa iyasebenza, okubangela ukuthi i-inverter isebenze ngokuhlehla.