Synchronous motors of alternating current are electric machines that convert electrical energy (supplied in the form of sinusoidally changing in time or “alternating” current) in the rotation of mechanical energy when the magnetic fields and conductors are interacted. Unlike engines that operate directly on direct current, alternating current electric motors, as a rule, do not require brushes and switches.
Synchronous motors of alternating current can be divided into two categories:
Asynchronous / synchronous engines synchronous engines
The rotor of the synchronous motors of alternating current rotates synchronously with the excitation field (t. e. no “slip”). The rotor magnetization is produced using a constant magnet in a gastulous structure or using alternating currents supplied through sliding or brush rings (high engine power).
These engines maintain constant speed for any load. When the load exceeds the nominal load, the engine “falls out” of synchronism and ceases to act. Since these engines operate at a fixed speed (which can be adjusted by changing the frequency of the supply voltage), they are suitable for high -precision drives, where accurate speed regulation is required.
Synchronous engines can be made in order to work at various power values on the basis of the excitation of the rotor. It is common to use the synchronous engine as a synchronous compensator of more than excitation of the rotor, forcing it to work with a leading power coefficient. With the help of such a synchronous compensator, the general power factor, the production plant, for example, can be improved.