Adjustable speed drives (ASDs) or variable speed drives (VSDs), also called variable frequency drives (VFDs), typically control a motor's velocity or torque output. Most adjustable frequency drives ...

However, if the system requires varied airflow, then using a variable-speed drive can save a lot of energy. The power requirement varies as the cube of the speed, so if airflow requirements are only ...

The way we control the speed of fan motors or pump motors has tremendously changed in the past two decades with the introduction of variable-frequency drives (VFDs), aka variable-frequency controllers ...