Is it an inverter or a VFD?

VFD Variable frequency drive


Both.  Inverter is a term frequently used to describe a type of ac variable speed drive.  However, inverter is also the term used for a device that converts a supply voltage from dc to ac: a typical inverter application may be to convert 12V dc from a car battery to 240V ac to run an appliance such as a TV.  So what do we mean by inverter drive and what should we call it?


So what is an inverter?

In this instance were referring to an electronic device for controlling the speed of an ac induction motor by varying the voltage and varying the frequency of the supply to the motor, so they’re sometimes called VVVF drives.  There is however no single term used although variable frequency drive (VFD) is both popular and a good description of the device’s function.  Other terms include ac variable speed drive (VSD); adjustable frequency drive (AFD); variable speed controller and so on.



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