How VFD's can save energy

Explain how a VFD can save electrical energy

A VFD can avoid a high starting current by setting the acceleration time. In my opinion, the VFD can be used as control energy not for saving energy in the whole application. It depends on the type of load and acceleration time to reach the set value speed which is linear with frequency as well as power usage.

Devices such as pumps and fans have an ideal speed for efficiency. With a VFD you can maintain that speed, if you dropped it across the line you most likely wouldn’t be at peak efficiency. It does not save energy until you operate it for the desired frequency to serve the desired operation both should be appropriate for the system.