What is the purpose of the stator in both classes of AC motors?

• A. Create a rotating magnetic field.
• B. Power the rotor directly.
• C. Store electrical energy.
• D. Provide cooling.

Answer: (A)

The stator in AC motors creates a rotating magnetic field. By energizing the stator windings with AC in a properly phased sequence, the magnetic poles sweep around the stator. In induction motors, this rotating field induces currents in the rotor and, through interaction with the field, produces torque that spins the rotor. In synchronous motors, the rotor carries DC excitation or permanent magnets and is pulled into step with the rotating field, again using that same rotating magnetic field to generate torque. The other functions listed—powering the rotor directly, storing energy, or cooling—are not the stator’s primary role.