DKIST uses induction motors in many applications.
Almost all of our induction motors operate from 480VAC, 3 phase, 60 Hz electrical power supply.
Most of our induction motors are controlled by variable speed drives.
Several applications use multiple motors and drives operating in tandem to move large loads.
Induction motors are simple. They only require 3 or 4 wires for electrical power connection.
Very simply: the 3 phase electrical supply excites coils in the fixed (stator) windings.
Three phase power circulates through the coils. Current passing through the coils produces a magnetic field.
The coils are wound with three phases equally spaced around the circumference of the stator.
Each phase produces a magnetic field that goes up and down as the AC voltage changes. The magnetic fields produce a magnetic flux along the direction of the voltage. A force in a specific direction is also called a ‘Vector’.
The combination of three magnetic vectors produces a (resultant) rotating magnetic force.
The rotating shaft of the motor has conductors arranged in a circle that react to the magnetic field. Most of the induction motors that we use have iron bars as the conductors. The circular collection of iron bars is commonly called a Squirrel Cage.
A current is induced in each bar as the magnetic field rotates past it. The current flowing through the bar creates it own magnetic field. The magnetic field in the bar is opposite in polarity to the rotating magnetic field. Magnetic opposites attract: so the magnetized bar is attracted to the rotating magnetic field.