This document written by Steve Bowling, Application Segments Engineer at Microchip Technology, discusses how motor works and describes the AC induction motor, variable-speed ACIM control, and FOC.

Somewhere in most engineering educations, there’s a class on induction motors. Students learn about shaded-pole motors, two-phase and three-phase motors, squirrel cage motors, and DC-excited motors.

Demand for low-cost, robust motor drives has spurred increased use of sensorless vector control of induction and BLDC motors — in everything from consumer products to industrial applications, in ...