Statorfeld

Statorfeld, or stator magnetic field, is the stationary magnetic field generated by the windings of the stator in an electric machine such as a motor or generator. It provides the magnetic environment that interacts with the rotor to convert electrical energy to mechanical energy or vice versa. In alternating-current machines, the stator field is typically created by three-phase windings arranged in slots around a laminated stator core.

The stator field is produced by energizing the stator windings with an electric supply. In three-phase machines, the combination of three phase-shifted windings produces a magnetic field that rotates at a speed determined by the supply frequency and the machine’s pole count. In synchronous machines, the rotating magnetic field is synchronized with the stator supply, while in induction machines the rotor lags behind the rotating field by slip, inducing currents that generate torque.

The magnetic circuit consists of a laminated iron core to minimize eddy currents, windings forming the MMF (magnetomotive force), and an air gap between stator and rotor. The flux distribution can be nearly sinusoidal for smooth torque or shaped by winding geometry for specific pole configurations (distributed versus concentrated windings; salient versus non-salient poles).

Applications and variations: The concept applies to motors and generators, including induction machines, synchronous machines, and brushless motor designs. In DC machines, a separate or integrated field winding on the stator creates the field, while the rotor may carry the armature. Losses include core losses, copper losses in windings, and leakage flux.