Lub Variable Frequency Drive (VFD) yog ib hom kev tswj lub cev muaj zog uas tsav lub tshuab hluav taws xob los ntawm kev sib txawv ntawm qhov zaus thiab qhov hluav taws xob nkag mus rau lub tshuab hluav taws xob. Lwm lub npe rau VFD yog qhov sib txawv ntawm kev tsav ceev, hloov ceev tsav, kho zaus tsav, AC tsav, microdrive, thiab inverter.
Zaus (los yog hertz) ncaj qha ntsig txog lub cev muaj zog ceev (RPMs). Hauv lwm lo lus, qhov nrawm dua, qhov nrawm dua RPMs mus. Yog tias daim ntawv thov tsis xav tau lub tshuab hluav taws xob kom khiav ntawm qhov nrawm, VFD tuaj yeem siv los nce qhov zaus thiab qhov hluav taws xob kom tau raws li qhov yuav tsum tau ua ntawm lub tshuab hluav taws xob lub cev muaj zog. Raws li daim ntawv thov lub cev muaj zog qhov xav tau hloov pauv, VFD tuaj yeem yooj yim tig los yog nqis lub cev muaj zog kom tau raws li qhov yuav tsum tau ua.
