What are compensating windings also known as?

Compensating windings are also known as interpole windings. Interpole windings are used in certain types of electric motors and generators, particularly in DC machines, to help improve performance by alleviating armature reaction effects. The interpoles are strategically placed between the main poles of the machine and are connected in series with the armature. This connection allows them to generate a magnetic field that counteracts the distortion created by the armature current, thus maintaining the voltage and improving the machine's overall efficiency and stability.

The other options represent different types of windings with distinct functions. Series windings refer to windings that are connected in series with the armature and primarily affect the motor’s torque characteristics. Field windings are typically used in the context of generating fields for electromagnets, while coil windings can refer to various configurations in different electrical components. Each of these has specific roles in motor and generator design but does not match the defining characteristics that identify compensating windings as interpole windings.