Reactivated with ANSI approval, ANSI/NEMA C50.41-2012 applies requirements to polyphase induction motors intended for use in power generating stations including: frame size larger than NEMA 440 series ...

Motor Selection for Adjustable-Speed Drives 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 ...

The great advantage of polyphase motors is, for a given number of poles, a smoother, more intense whirling field; such motors, in myriad forms, launched the electrical age of heavy industry.

Also the polyphase induction motor is no longer to retain the great disadvantage in the matter of speed regulation, which makes it inferior to the continuous-current shunt motor, for successful ...