Synchronous motors. A synchronous motor is one in which the rotor normally rotates at the same swiftness as the revolving field in the device. The stator is similar to that of an induction machine consisting of a cylindrical iron body with windings, usually three-phase, situated in slots around the inner periphery.
generally, synchronous motors are used for applications where precise and constant speed is necessary. Low power applications of these motors include positioning machines. These are also applied in robot actuators. Ball mills, clocks, record gamer turntables also make use of synchronous motors.
The principle of procedure of a synchronous motor can 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 is to establish a magnetic field rotating at 120 f/p revolutions per minute for a frequency of f hertz and for p poles. A primary current in a p-pole field winding on the rotor may also produce a magnetic field rotating at rotor speed. If the rotor acceleration is made add up to that of the stator field and there is no load torque, these two magnetic fields will have a tendency to align with one another. As mechanical load can be applied, the rotor slips back a number of degrees with respect to the rotating field of the stator, developing torque and continuing to be drawn around by this rotating field. The angle between the fields raises as load torque can be increased. The maximum available torque is achieved when the angle by which the rotor field lags the stator field is usually 90°. Software of more load torque will stall the motor.
One benefit of the synchronous motor can be that the magnetic field of the device can be Stainless Steel Chain produced by the direct current in the field winding, to ensure that the stator windings need to provide only a power component of current in stage with the applied stator voltage-i.e., the motor can operate at unity power factor. This condition minimizes the losses and heating in the stator windings.