Design of Rotating Electrical Machines, 2nd Edition

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Windings of Electrical Machines

The operating principle of electrical machines is based on the interaction between the magnetic fields and the currents flowing in the windings of the machine. The winding constructions and connections together with the currents and voltages fed into the windings determine the operating modes and the type of the electrical machine. According to their different functions in an electrical machine, the windings are grouped for instance as follows:

• armature windings;
• other rotating-field windings (e.g. stator or rotor windings of induction motors);
• field (magnetizing) windings;
• damper windings;
• commutating windings; and
• compensating windings.

Armature windings are rotating-field windings, into which the rotating-field-induced voltage required in energy conversion is induced. According to IEC 60050-411, the armature winding is a winding in a synchronous, DC or single-phase commutator machine, which, in service, receives active power from or delivers active power to the external electrical system. This definition also applies to a synchronous compensator if the term “active power” is replaced by “reactive power.” The air-gap flux component caused by the armature current linkage is called the armature reaction.

An armature winding determined under these conditions can transmit power between an electrical network and a mechanical system. Magnetizing windings create a magnetic field required in the energy conversion. All machines do not include a separate ...