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 ...

For the PDF version of this article, click here. More than 80% of the motors bought each year continue to be low-cost single-phase ac motors. Because these motors are not very efficient when ...

Once the control method of choice only in high-performance industrial ac-servo drives, FOC (field-oriented control) is finding its way into lower end industrial and many appliance applications with ...