20.06.2014 13:30

Control the voltage and frequency

The Variable frequency drive


A VFD (Variable Frequency Drive) is a type of controller that drives electric motors by adjusting the voltage and frequency. This frequency is directly linked to the motorís speed, so the quicker the frequency, the quicker the speed. Some applications donít require an electric motor to function at full speed, and this is when the VFD is used to control the voltage and frequency of the device in order to meet the necessary requirements. You can simply turn the VFD down or up to adjust the motor speed at the level that meets your needs.

The converter is the first stage of a VFD, comprising of 6 diodes, which are identical to plumbing valves. These diodes allow the current to move in only one direction that is shown by the pointer in the diodeís symbol. This 6-pulse VFD is the standard configuration for current frequency drives.

Advantages


If your application does not need to be running at full speed, you can reduce energy consumption by controlling the motor using VFD. By operating your applications at reduced speed, fewer errors will occur which result in increased production levels. Your company can earn higher revenues this way as you eliminate jerks from conveyor belts whenever starting up the motor.

By installing optimised motor control systems and upgrading to variable frequency drives, your facility can reduce energy by as much as 70 per cent. In addition, the use of VFDs greatly enhances product quality whilst reducing production costs at the same time. In as little as 6 months, your business can be eligible for receiving energy efficiency tax rebates and other incentives.

Not only will you save money on energy, when you opt for VFDs you can also extend your equipment life by doing less maintenance. Because you can control the voltage and frequency of the motor, the variable frequency drive will offer higher protection for your motor so that it doesnít face issues such as thermal overloads and under or overvoltage.

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