Asynchronous Synchronous Machine

AFM is an asynchronized synchronous machine (a kind of dual-power machine ).

The main difference between an AFM and a conventional synchronous machine is the presence of two field windings located along and across the axis. Therefore, the AFM rotor has essentially a two-phase winding. In normal mode, the rotor is powered by direct current, this mode is no different from the mode of operation of a conventional synchronous machine. However, in emergency conditions, when the synchronous rotation of the rotor with the stator field is violated (short circuits in the network, rotor swings, etc.), the field windings are powered by alternating slip frequency currents, 90 ° out of phase, resulting in an excitation field rotating relative to the rotor . The frequency of the excitation currents is automatically and continuously regulated so that the excitation fields and the armature rotate synchronously, so that they create a constant-sign torque. As a result, the machine does not fall out of synchronism and the stability of its operation increases, which is the advantage of this machine.

By nature, this machine is a dual-power machine. To realize the indicated advantages of this machine, the multiplicity (ceiling) of the excitation voltage must be high (4-5) and strong regulators must be used. It is advisable to power the field windings from frequency converters.

Advantages : high resistance to loss of synchronism

Disadvantages : significant high cost of control and management system

The idea of ​​AFM was proposed by the Soviet electric engineer A. A. Gorev.