AAP Products: VFD
What is a VFD?
A Variable Frequency Drive (VFD) is a type of motor controller that drives an electric motor by varying the frequency and voltage supplied to the electric motor. Other names for a VFD are variable speed drive, freak drive, adjustable speed drive, adjustable frequency drive, AC drive, microdrive, and inverter.
Frequency (or hertz) is directly related to the motor’s speed (RPMs). In other words, the faster the frequency, the faster the RPMs go. If an application does not require an electric motor to run at full speed, the VFD can be used to ramp down the frequency and voltage to meet the requirements of the electric motor’s load. As the application’s motor speed requirements change, the VFD can simply turn up or down the motor speed to meet the speed requirement.
When Do You Use a VFD?
There are many reasons why we may want to adjust this motor speed. For example, using this technology to:
- Save energy and improve system efficiency
- Convert power in hybridization applications
- Match the speed of the drive to the process requirements
- Match the torque or power of a drive to the process requirements
- Improve the working environment
- Lower noise levels, for example from fans and pumps
- Reduce mechanical stress on machines to extend their lifetime
- Shave peak consumption to avoid peak-demand prices and reduce the motor size required
In addition, today’s drives integrate networking and diagnostic capabilities to better control performance and increase productivity. So, energy savings, intelligent motor control and reduction of peak-current drawn are three great reasons to choose a VFD as the controller in every motor-driven system.
The most common uses of a VFD are for control of fans, pumps and compressors, and these applications account for 75% of all drives operating globally.
Soft starters and across-the-line contactors are other, less sophisticated types of motor controllers. A soft starter is a solid-state device and provides a gentle ramp-up to full speed during startup of an electric motor, while an across-the-line contactor is a type of motor controller that applies the full line voltage to an electric motor.
To learn more about the VFD’s offered at Associated Air Products, check out our products from Danfoss.