Abahlinzeki bemishini yokonga i-elevator bakukhumbuza ukuthi ngokuthuthuka okuqhubekayo kobuchwepheshe, iziguquli zefrikhwensi kancane kancane seziqalile ukusetshenziswa ezimpilweni zethu ezijwayelekile, njengezimo zomoya, amakheshi, nezimboni ezisindayo. Ukusetshenziswa kobuchwepheshe befrikhwensi eguquguqukayo ku-air conditioning sekwaziwa kakhulu kubantu, kodwa luncane ulwazi mayelana nokusetshenziswa kobuchwepheshe befrikhwensi eguquguqukayo kumakheshi.
Njengamanje, amakheshi amaningi asebenzisa ukulawulwa kwesivinini esishintshashintshayo kanye nokulawulwa kwesivinini se-voltage eguquguqukayo, kanti iziguquli zemvamisa zibalelwa cishe ingxenye yamakheshi. Izinga elivamile le-elevator ibhodi elinengqondo+i-frequency converter. Owokuqala uwu-opharetha oqapha impendulo yesiginali ngayinye ku-lifti, kuyilapho eyakamuva ihlanganiswe ngokuphelele nama-actuator enjini kanye namabhuleki. Ake siqale ngesekhethi yangaphandle enembile kakhulu. Okokuqala, i-frequency converter ingafinyelela ukulawulwa kwesivinini esingenasinyathelo se-motor ngokumane ixhume izintambo ezintathu eziyinhloko ze-motor: R, S, kanye ne-t. Ukuze uthole ukuqonda okujulile kwesimiso sokulawulwa kwesivinini sokuguqulwa kwemvamisa, ukuthatha i-asynchronous motor yesigaba sesithathu njengesibonelo, ku-symmetry yezigaba ezintathu ze-stator winding ye-motor ye-asynchronous yezigaba ezintathu, insimu yamagnetic ejikelezayo ikhiqizwa, enqamula umqhubi we-rotor futhi ifake okwamanje ku-rotor winding. I-current izobangela ukuthi i-rotor winding ikhiqize amandla kazibuthe ajikelezayo, ngaleyo ndlela iqhube i-rotor ukuthi ijikeleze. Imvamisa yokuphumayo inquma ijubane lokujikeleza lensimu kazibuthe ezungezayo, ngaleyo ndlela kuzuzwe ukulawulwa kwesivinini se-rotor. Kukhona ifomula yesivinini esivumelanayo n=60f/p, ehlobene nalokhu. Yiqiniso, leli zinga libhekisela enanini le-stator windings. Ngokuvamile sithola ukuthi i-voltage ye-inverter kumenyu yokuqapha i-inverter iphakeme ngokulinganayo noma iphansi, ngoba emazingeni okusebenza okulinganiselwe, uma i-voltage ye-frequency iphansi ezimweni ezithile, izobangela i-magnetism eqinile futhi ishise imoto. Ngakolunye uhlangothi, uma izinga lokugeleza linganele, lizobangela ngokuqondile i-torque ephumayo yemoto kagesi.
Isekhethi eyinhloko yesiguquli esivamile sihlanganisa izingxenye ezintathu: isifunda esilungisa kabusha, isifunda esimaphakathi, kanye nesekhethi ye-inverter. Isekhethi yokulungisa ilula futhi idlula ngokuqondile ebhulohweni lezigaba ezintathu (isilungisi esingalawulwa se-diode, isilungisi esingalawuleki se-thyristor) samanje esiqondile, esibuye saziwe ngokuthi i-DC bus voltage. Lapho isifunda esiphakathi phakathi kwe-rectifier circuit kanye ne-inverter circuit, okuhlanganisa ama-circuits ajwayelekile, ama-circuits okuhlunga, namabhulokhi amabhuleki, i-inverter ingabona i-capacitor enkulu esebenza njengesilawuli sokuhlunga. Ngenxa yokuthi i-DC pulsation yokulungisa kabusha isadinga ukuhlungwa, inganikeza ukuhlinzekwa kwamandla okuzinzile kwe-DC. Ibhokisi langaphandle le-braking resistor module inverter liyasetshenziswa. Kulo mthamo omkhulu, lapho umsingathi ehla futhi amabhuleki, i-motor izongena ku-generator, futhi isifunda se-inverter yamandla singagcina amandla kagesi ku-capacitor enkulu. Uma uphoqeleka ukuthi uhambise izilungiselelo zamandla amaningi kakhulu, isiguquli silawula isixhasi sokubhuleka sangaphandle ukuze sidle amandla amaningi, ngaleyo ndlela sigweme isiguquli se-overvoltage. Okokugcina, isifunda se-inverter siyingxenye ebaluleke kakhulu futhi esengozini ye-inverter. Izindlela ezijwayelekile zokulawula ukuguquguquka kwemvamisa zihlukaniswe ngezigaba ezimbili: i-PAM (Ukuguquguquka kwe-Pulse Amplitude) kanye ne-PWM (Ukuguquguquka Kobubanzi be-Pulse). Kodwa-ke, i-PAM nayo idinga ukufaniswa namasekhethi okulungisa kabusha alawulekayo kwezinye iziguquli zefrikhwensi, ezidinga izidingo zokucupha eziphezulu futhi ezinokukhubazeka okukhulu. Ukulawula i-PWM kuyindlela esetshenziswa kakhulu. I-PWM modulation iyithuluzi elishintshayo elisekelwe kumasekhethi okuguqula imvamisa ephezulu, elawula isikhathi sokushintshwa kwemvamisa yokuphumayo ngokushintsha ububanzi be-voltage pulse. Manje isetshenziswa kumadivayisi amaningi okushintsha afana ne-IGBT, bese ithinta injini (umthwalo we-inductive) enama-high-frequency pulses, okusiza ukukhiqiza amaza e-sine nokulawula i-voltage kanye nemvamisa, ngaleyo ndlela kuzuzwe ukulawulwa kwesivinini esingenasinyathelo.
I-Elevator frequency converter ayilona nje ithuluzi elikhethekile lokulawula ikheshi, kodwa futhi ingumkhiqizo osezingeni eliphezulu phakathi kweziguquli zamandla amancane naphakathi nendawo. Ithuthukisa ukusebenza kahle kwamakheshi, isebenze kahle, futhi inwebe isikhathi sempilo yemishini. Ihlanganiswe ne-PLC noma i-microcomputer control, iphinde ibonise ukuphakama kokulawula ngaphandle kokuthinta: izintambo ezenziwe lula, isilawuli esivumelana nezimo, ukusebenza okuthembekile, nokugcinwa okulula nokuqapha amaphutha. Ukufaka idivaysi yokonga amandla empendulo yekheshi kusiguquli sefrikhwensi yekheshi kungaguqula ngempumelelo amandla kagesi avuselelwe agcinwe ku-capacitor yesiguquli sefrikhwensi yekheshi ibe amandla kagesi e-AC futhi iwabuyisele kugridi yamandla, iphendule ilifti ibe "isikhungo samandla" esiluhlaza ukuze sinikeze amandla kwezinye izisetshenziswa nokonga amandla.