AC drive and DC drive systems are basically constructed of three basic components.  These are the rectifier, the inverter, and a set of controls.  The rectifier converts the fixed frequency AC input voltage to DC while the inverter switches the rectified DC voltage to an adjustable frequency AC output voltage.  If desired, the inverter also controls output current flow.  The DC link connects the rectifier to the inverter.  The set of controls directs the rectifier and inverter to produce the desired AC frequency and voltage to meet the needs of the AC drive/DC drive system at any given time.

The components of which AC drive and DC drive systems consist of ensures that these electric drives are extremely advantageous.  Apart from saving energy and improving control, the makeup of AC drive and DC drive systems ensures that electric drive technology can now be applied to manufacturing equipment previously considered too expensive or uneconomical.  Such applications are often unique to a particular industry and its equipment, or even to a particular facility.  Benefits related to cost, such as those obtained from improved quality, may be desirable for each application.