Synchronous motors. A synchronous electric motor is one where the rotor normally rotates at the same rate as the revolving field in the machine. The Auto Chain stator is comparable to that of an induction machine comprising a cylindrical iron body with windings, usually three-phase, situated in slots around the internal periphery.
usually, synchronous motors are used for applications where precise and continuous speed is necessary. Low power applications of these motors include positioning devices. These are also applied in robot actuators. Ball mills, clocks, record player turntables also make use of synchronous motors.
The principle of operation of a synchronous electric motor could be understood by taking into consideration the stator windings to be linked to a three-phase alternating-current supply. The result of the stator current can be to establish a magnetic field rotating at 120 f/p revolutions per minute for a frequency of f hertz and for p poles. A direct current in a p-pole field winding on the rotor will also produce a magnetic field rotating at rotor swiftness. If the rotor acceleration is made equal to that of the stator field and there is absolutely no load torque, these two magnetic fields will tend to align with one another. As mechanical load is applied, the rotor slips back again several degrees with respect to the rotating field of the stator, developing torque and ongoing to end up being drawn around by this rotating field. The angle between the fields boosts as load torque can be increased. The maximum available torque is attained when the angle by which the rotor field lags the stator field is certainly 90°. App of more load torque will stall the engine.
One benefit of the synchronous motor is that the magnetic field of the machine can be produced by the immediate current in the field winding, so that the stator windings have to provide just a power component of current in stage with the applied stator voltage-i.e., the motor can operate at unity power factor. This problem minimizes the losses and heating in the stator windings.