Variable Frequency Drives

A Brief Overview of Variable Frequency Drives


The variable-frequency-drive is also referred to as the Adjustment Frequency Drive is the Variable speed Drive the AC Drive or a Micro Drive. It’s a type of adjustable speed drive that is used in the electro-mechanical drive systems for controlling the AC motor speed and the torque

VFD can be used in not only in small appliances but also in large mine mill drive and compressors. Valuable Frequency Drives are available in low and the medium voltage.
AVDF Drive, the device that is used in the drive system usually has three main subsystems, AC motor, Main Drive Comptroller Assembly and Operator Interface.

AC Motor

These motors are suitable for most purposes and are the most economical motors. Motors that are used are those designed for fixed speed operations.


This is the main, which controls all the parts of the device and has many other sub systems that are working on their own. A single phase induction motor runs by the principal of the EMF induction because of flux. The only difference is that it runs on single phase supply. Its methods are usually governed by the theories of Double Revolving field and The Cross field theory with regards to Variable Frequency Drives.

Operator Interface

The operator interface provides a means for an operator to start and stop the motor and adjust the operating speed. Other functions of operator control include;reversing and switching between manual speed adjustments and automatic control from an external process control signal. It includes an alphanumeric display and indication lights and meters.These provide information about the operation of the drive.On the front of the VFD controller, an operator interface keypad is provided.

Benefits of using VFD

•    Energy savings is one of the benefits of using VFD.They allow you to match the speed of the motor driven equipment to the process requirements thus cutting down energy costs. They consume less energy than other speed control techniques when load requirements are less than full speed.
•    It has accurate process control. They can be programmed to run the motor at a precise speedto stop at a precise position or to apply a specific amount of torque.
•    Thirdly, extended equipment life and reduced maintenance is another benefit.VS drives gradually ramp the motor up to operating speed to lessen mechanical and electrical stress.This reduces maintenance and repair costs and extends the life of the motor and driven equipment.

In conclusion, using the Variable Frequency Drives (VFD) with motor combinationcan lead to significant energy savings and recovery. Energy savings and the operating costs are much higher compared to the cost of installing the drive.

These kind of the drives are used in many things that we use daily, as their function is what makes them separate from the rest. They are reliable and most easy in order to understand