1.Make Process Controllable
A VFD allows you to control the motor at any speed throughout its entire range
By adding transducers and or controllers a VFD allows you to control just about any process or application you may have that uses a motor.
Built in application on VFD's allows for easy quick programming for just about any control need.
Built in communication protocols allow the VFD to talk to most automation system for control and feedback information.
2.Decrease stress on equipment
A VFD will "soft start" a motor with adjustable ramp times this is when the motor would have the most stress.
A VFD always monitors the motor to control it to its maximum efficiency and protect the motor from working too hard.
When the motor is slower the entire system belts,pulleys,coupling,bearing,fans,impellers any part of the system the motor touches has less stress on it with a VFD controlling the motor.
VFD reduces the voltage and hertz there for amperage follows along with total energy used.