Components and Operation of Variable Frequency Drive
It works in four main stages
- Rectifier: In this stage the incoming frequency AC power is converted in DC by using silicon controlled rectifiers (SCR’s), Diodes, Transistors.
- DC link: As the converted DC has some fluctuations, the DC link helps and removes them. It is used to reduce the ripple.
- Inverter: This is the heart of the VFD. This coverts the fixed DC into AC by using Insulated Gate Bipolar Transition (IGBT). It forms a Variable Frequency Waveform of AC. The inverter controls the output frequency.
- Control Circuit: This is the main part of Variable Frequency Drive (VFD). Here it will receive all the input from the user and control everything. It will act as the control center and monitors voltage and the current.
Operation of Variable Frequency Drive
- Ac input: The VFD has input of AC from the mains.
- Rectification: It will convert the AC input to DC.
- DC link: Here the DC voltage is stabilized using capacitors.
- Inverter: The control system will instruct the inverter to convert the DC voltage to AC with Variable Frequency.
- AC output: The output of the Variable frequency is supplied to the motor.
- Motor Speed Control: The speed of the motor is directly connected to the frequency. So if the frequency is increased the speed is increased and if it is decreased, then it is slow speed.
Variable Frequency Drive
Variable Frequency Drive (VFD) is the type of AC motor drive that controls the speed and the torque. It can control the speed by changing the frequency of the current. They can also control the speed and torque of the motor by changing the voltage. They are the motors of the modern world. Most industries are now shifting to use VFD as they are easy to use and can be controlled by software. VFDs are not only used in large-scale industries but also used in small-scale industries as well.
Table of Content
- Variable Frequency Drive
- Types
- Components and Operation
- Working
- Advantage
- Disadvantage
- Applcations