The nuances of variable-frequency drives: Get an inside view of induction-motor control by varying frequency using PWM

摘要

You can divide the world of electronic motor drives, which control the speed, torque, direction, and resulting horsepower of a motor, into two categories: ac and dc. 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 field circuits. This teardown of the Schneider Electric Altivar 12 variable-frequency drive details the key features that define these drives.