VARIABLE FREQUENCY DRIVE:
Electric motors are the workhorses of Industries. They convert electrical energy to mechanical energy with very high efficiency. Electric motors cover the majority of energy consumers & so are the range of applications ranging from industrial manufacturing & processing to commercial & domestic environment.
Some of the common applications of electric motors are pumps, fans, mixers compressors, conveyors, mills, cranes, cars, machine tools. It is often desirable to operate a motor at variable speed for various purpose like saving energy, improving efficiency, controlling the torque of the process etc. Automation of industrial processes has lead to variable frequency drives of A.C. Motors.
Variable frequency drive (VFD) is a technique often used to achieve the adjustable speed of A.C. motors to control its speed as well as torque. Another important need for VFD’s is to save a substantial amount of energy, as electric motors are one of the major energy consumers in industries & having an efficient process is very important.
In this technique, power electronic devices are used to vary the frequency of the input power to the electric motor by a technique called pulse width modulation (PWM) & thereby controlling the speed of the motor.
Variable frequency drive (VFD) usage has increased dramatically in HVAC applications. The VFD’s are now commonly applied to air handlers, pumps, chillers & tower fans.
A better understanding of VFD will lead to improved application & selection of equipment. This course is intended to provide a basic knowledge & understanding of common VFD terms & basic programming parameters which is required for fresher engineers at entry level in industry.