Umphakeli weyunithi ye-frequency converter braking unit ukukhumbuza ukuthi ekukhiqizweni kwezimboni, ukuze kuthuthukiswe umphumela wokonga amandla futhi kuncishiswe ukulahleka kwamandla ngesikhathi senqubo yokubhuleka, kuyadingeka futhi ukubuyisela amandla okunciphisa bese uphendula ngawo kugridi yamandla ukuze kuzuzwe umphumela wokonga amandla. Njengamanje, lapho izifunda ezihlukahlukene e-China zibhekana nokushoda kwamandla ngenxa yokuthuthuka komnotho okusheshayo, ukukhuthaza nokusebenzisa amabhuleki empendulo kunokubaluleka okubalulekile kokonga ugesi. Ngakho-ke, ukusheshisa ucwaningo nokukhiqizwa kwemikhiqizo yasekhaya ehlobene kunokubaluleka okusebenzayo okubalulekile.
Njengamanje, ibhuleki elula yokusetshenziswa kwamandla isetshenziswa kabanzi ezinhlelweni zokulawula isivinini esishintshashintshayo se-AC, ezinobubi njengokumosha amandla kagesi, ukushisisa okungazweli kakhulu, kanye nokusebenza kabi kwamabhuleki okusheshayo. Lapho ama-asynchronous motors evamise ukubhuleka, ukusebenzisa i-feedback braking kuyindlela ephumelela kakhulu yokonga amandla futhi kugwema ukulimala kwemvelo nezinto zokusebenza ngesikhathi sokubhuleka. Imiphumela egculisayo isizuziwe ezimbonini ezifana nezitimela zikagesi kanye nokumba uwoyela. Ngokuvela okuqhubekayo kwemishini emisha ye-elekthronikhi yamandla, ukwanda kwezindleko, kanye nokuqwashisa kwabantu ngokongiwa kwamandla kanye nokunciphisa ukusetshenziswa, kunezinhlobonhlobo zamathemba okusebenza.
Idivayisi yokubhuleka impendulo yamandla ifaneleka ikakhulukazi ezimweni lapho amandla emoto emakhulu, njengamakhulu noma alingana no-100kw, umzuzu we-inertia gd2 wemishini mkhulu, futhi ungokwesistimu yokusebenza eqhubekayo yesikhashana esifushane. Ukwehliswa kokunciphisa ukusuka kwijubane eliphezulu kuye kwijubane eliphansi kukhulu, isikhathi sokubhuleka sifushane, futhi ukubhuleka okuqinile kuyadingeka. Ukuze kuthuthukiswe umphumela wokonga amandla futhi kuncishiswe ukulahlekelwa kwamandla ngesikhathi senqubo yokubhuleka, kuyadingeka futhi ukubuyisela amandla okwehlisa izinga kanye nokuphendula ngawo kugridi yamandla ukuze kuzuzwe umphumela wokonga amandla.
Umgomo wokubhuleka impendulo
Kuhlelo lokulawula isivinini esishintshashintshayo, ukuncishiswa nokumiswa kwemoto kufinyelelwa ngokunciphisa kancane kancane imvamisa. Okwamanje lapho imvamisa incipha, isivinini se-synchronous se-motor siyehla ngokufanele. Kodwa-ke, ngenxa ye-inertia yemishini, isivinini se-rotor se-motor asishintshi, futhi ukuguqulwa kwayo kwejubane kunesikhathi esithile. Ngalesi sikhathi, isivinini sangempela sizoba sikhulu kunejubane esinikeziwe, okuholela esimweni lapho amandla e-electromotive engemuva emoto ephakeme kune-DC terminal voltage u yesiguquli sefrikhwensi, okungukuthi, i-e>u. Kuleli qophelo, i-motor kagesi iba i-generator, engadingi nje kuphela ukunikezwa kwamandla kusuka kugridi, kodwa futhi ingathumela ugesi kugridi. Lokhu akugcini nje ngokuba nomphumela omuhle wokubhuleka, kodwa futhi kuguqula amandla e-kinetic abe amandla kagesi, angathunyelwa kugridi ukuze athole amandla, abulale izinyoni ezimbili ngetshe elilodwa. Yiqiniso, kufanele kube neyunithi yedivayisi yempendulo yamandla yokulawula okuzenzakalelayo ukuze uyifinyelele, njengoba kuboniswe kumdwebo wohlelo ku-Figure 1. Ngaphezu kwalokho, isifunda sempendulo yamandla kufanele futhi sifake ama-reactors e-AC kanye ne-DC, ama-absorber capacitance absorber, amaswishi kagesi, njll.
Isimiso nezici ze-frequency converter feedback braking
Umfanekiso 1 Umdwebo weSkimu wesekethe yokubhuleka ye-frequency converter
Njengoba kwaziwa kahle, umjikelezo wokulungisa ibhuloho weziguquli ezivamile azilawuleki, ngakho-ke awukwazi ukuzuza ukudluliswa kwamandla okuqondiswa kabili phakathi kwesekethe ye-DC kanye nokunikezwa kwamandla. Indlela ephumelela kakhulu yokuxazulula le nkinga ukusebenzisa ubuchwepheshe be-inverter obusebenzayo, futhi ingxenye yokulungisa ithatha isilungisi esihlehliswayo, esikwaziwa nangokuthi isiguquli se-grid side. Ngokulawula i-inverter eseceleni kwegridi, amandla kagesi avuselelwe aguqulelwa kumandla we-AC ngefrikhwensi efanayo, isigaba, kanye nemvamisa njengegridi, futhi abuyiselwa kugridi ukuze afinyelele ukubhuleka. Ngaphambilini, amayunithi e-inverter asebenzayo ayevame ukusebenzisa amasekhethi e-thyristor, angenza ngokuphepha ukusebenza kwempendulo ngaphansi kwegridi yegridi ezinzile engajwayele ukuba namaphutha (ukushintshashintsha kwegridi yamandla okungeqi ku-10%). Lolu hlobo lwesekhethi lungenza ngokuphephile ukusebenza kwempendulo yesiguquli ngaphansi kwamandla kagesi wegridi azinzile ajwayele ukuba namaphutha (ngokuguquguquka kwamandla kagesi wegridi okungeqile ku-10%). Ngoba ngesikhathi sokusebenza kwebhuleki yokukhiqiza amandla, uma isikhathi sokubhuleka kagesi wegridi sikhulu kuno-2ms, ukwehluleka ukushintsha kungase kwenzeke futhi izingxenye zingalimala. Ngaphezu kwalokho, ngesikhathi sokulawula okujulile, le ndlela inesici samandla aphansi, okuqukethwe okuphezulu kwe-harmonic, nokushintshashintsha okugqagqene, okuzodala ukuhlanekezelwa kwe-wave wave wave voltage grid. Ngesikhathi esifanayo ukulawula inkimbinkimbi kanye nezindleko eziphezulu. Ngokusetshenziswa okungokoqobo kwemishini elawulwa ngokugcwele, abantu baye bakha iziguquli eziguqulekayo ezilawulwa yi-chopper besebenzisa isilawuli se-PWM. Ngale ndlela, ukwakheka kwesiguquli eseceleni kwegridi sifana ngokuphelele nesesiguquli, zombili zisebenzisa isilawuli se-PWM.
Kusukela ekuhlaziyweni okungenhla, kungabonwa ukuthi ukuze uzuze ngempela impendulo ye-energy braking ye-inverter, ukhiye ukulawula isiguquli eseceleni segridi.
Izici zokubhuleka impendulo
Uma sikhuluma ngokuqinile, isiguquli eseceleni segridi asinakubizwa nje ngokuthi "isilungisi" ngoba singasebenza njengokubili isilungisi kanye nesiguquli. Ngenxa yokusetshenziswa kwamadivaysi okuzicisha, ubukhulu nesigaba se-AC yamanje singalawulwa ngemodi ye-PWM efanele, okwenza indlela yamanje yokufaka ibe yigagasi le-sine futhi iqinisekise ukuthi isici samandla ohlelo ngaso sonke isikhathi sisondela ku-1. Lapho amandla okuvuselela ebuya ku-inverter nge-motor deceleration braking inyusa i-voltage ye-DC, isigaba sokufakwayo kwe-AC kusuka kugesi ovuselelwe kabusha ukuze kufinyelelwe amandla okusebenza avuselelwe kabusha. amandla okukhiqiza kabusha angabuyiselwa kugridi yamandla e-AC, kuyilapho isistimu isengakwazi ukugcina i-voltage ye-DC ngenani elinikeziwe. Kulokhu, i-inverter eseceleni yegridi isebenza kusimo se-inverter esisebenzayo. Lokhu kwenza kube lula ukuzuza ukugeleza kwamandla okuqondiswa kabili futhi kunesivinini sokuphendula esiguqukayo esisheshayo. Ngesikhathi esifanayo, lesi sakhiwo se-topology senza isistimu ilawule ngokugcwele ukushintshana kwamandla asebenzayo futhi asebenzayo phakathi kwezinhlangothi ze-AC ne-DC, ngokusebenza kahle okufika ku-97% kanye nezinzuzo ezibalulekile zezomnotho. Ukulahlekelwa ukushisa ngu-1% webhuleki yokusetshenziswa kwamandla, futhi ayingcolisi igridi yamandla. Isici samandla sicishe sibe ngu-1, esihambisana nemvelo. Ngakho-ke, i-feed braking ingasetshenziswa kakhulu ekusebenzeni okonga amandla kuzimo zokubhuleka impendulo ye-PWM AC, ikakhulukazi ezimeni lapho kudingeka khona ukubhuleka njalo. Amandla emoto kagesi nawo aphezulu, futhi umphumela wokonga amandla ubalulekile. Ngokuya ngezimo zokusebenza, isilinganiso somphumela wokonga amandla singaba ngu-20% noma ngaphezulu.