Many of these savings can be accomplished through the use of variable-frequency drives (VFD) (Figure 1). The world’s first mass-produced VFD was introduced in 1968. Computerization, the reduced cost ...

An ac drive controls ac induction motors and, like its dc counterparts, controls speed, torque, and horsepower. A dc drive typically controls a shunt-wound dc motor, which has separate armature and ...

The resonance frequency is a function of the VFD carrier frequency and impedance of the circuit; therefore, it’s specific to the site conditions. The resonance in an electrical system occurs when ...

Variable speed drives (VSDs), sometimes also known as variable frequency drives, are electronic devices used to regulate the speed of an ac induction motor. Electric motors consume approximately ...

These variable-frequency drives (VFDs) accurately control the speed of standard AC induction or synchronous motors. With VFDs, speed control with full torque is achieved from 0 rpm through the maximum ...

This is particularly true with the introduction of variable frequency drives (VFDs). Historically, you were stuck with a fixed speed on a prime mover or limited to using non-efficient, cost ...