Why Use Adjustable Speed Drives?

In general Variable Frequency Drives (VFD’s), also referred to as Adjustable Speed Drives (ASD’s), are used to:

  • Match the speed of the drive to the process requirements
  • Match the torque of the drive to the process requirements
  • Energy savings
  • Reduce maximum utility demand – electrical and cost
  • Meet utility flicker restrictions while starting large loads
  • Improve equipment life due to soft starting
  • Increase mechanical equipment life by running at lower speeds
  • Controlled application of torque
    • reduced water hammer effects
    • conveyors
  • Reduced pump cavitation problems
  • Reduce preventative and corrective maintenance costs by eliminating complex mechanical equipment – valves, dampers, etc.
  • Allows the use of standard induction motors while increasing performance in terms of torque, inrush and power factor
  • Reduce motor stress – transient torques, thermal heating at start condition, no limit of starts/hr., high inertia loads
  • Improve process control by ‘infinite’ speed control and better information / tie in with supervisory control system
  • Forward / Reverse
  • Regenerative braking
  • Environmental compliance requirements.  Many SCR / RTO pollution control equipment require the use of a VFD to operate optimally