Stator

The stator is the stationary part of many electric machines, serving as the fixed frame that contains the windings or magnets used to produce or respond to a magnetic field. In AC motors and generators, the stator provides the rotating magnetic field or hosts the armature windings where electrical power is produced or consumed.

In a motor, three-phase AC is applied to the stator windings. The energized windings produce a rotating magnetic field that interacts with the rotor, causing torque. In a generator, the rotor carries the magnetic field and the changing field induces AC in the stator windings, delivering power to the external circuit.

Construction generally features a laminated iron core with slots on the inner bore to hold windings. Laminations reduce eddy current losses at high speed. The windings are insulated and arranged in configurations such as distributed or concentrated, typically three-phase. The air gap between stator and rotor is critical for operating speed and torque.

Stators can be cylindrical or segmented with salient poles. Most common machines use a three-phase distributed winding in a cylindrical stator. In large machines, the stator core is cooled, often by air or water cooling, to manage heat generated by losses. The stator plays a central role in energy conversion by providing a durable, stationary structure that supports efficient flux transmission between windings and the rotor.