Prior to the advent of the adjustable-speed drive (ASD), the polyphase induction motor operated as a constant-speed motor. Figure 1 shows the well-known torque and current curves versus speed for the ...

All the motors produce either interaction torque, reluctance torque or a combination of both. The second article in this series discussed the underlying principles common to all motors. As we have ...

In a recent article, I wrote about step-motor system performance emphasizing key concepts that all engineers need to understand about this widely-used electro-magnetic-mechanical digital actuator. As ...

The two most important electric motors are the ac induction motor and the permanent magnet (PM) brushless synchronous motor, also known as the brushless dc or ac servo motor. These motors have ...