What is a variable speed drive?
The basic function of a variable speed drive (VSD) is to control the flow of energy from the mains to the process. Variable speed drives sit between the electrical supply and the motor. Power from the electrical supply goes into a drive and the drive then regulates the power that is fed to the motor.
Inside the drive the input power is run through a rectifier, that converts the incoming AC power to DC power. The DC power is fed into the capacitors inside the drive. This is done to smooth out the electrical waveform which provides the clean power supply for the next step. Power then flows from the capacitors to the inverter, that changes the DC power to the output AC power that goes to the motor.
This step allows the drive to adjust the frequency and the voltage that fed into to the motor based on your current process demands. This means you run your AC motors at the speed or with the torque according to the demand needed. This is why you can save large amounts of money using the AC drives.
Besides saving energy, variable speed drives also help you reduce maintenance costs, waste and even ambient noise emissions. They are also a great way to help meet your environmental goals
