Working of synchronous motors depends on the interaction of the magnetic field of the stator with the magnetic field of the rotor. The stator contains 3 phase windings and is supplied with 3 phase power. Thus, stator winding produces a 3 phased rotating Magnetic- Field.
What is a three-phase synchronous motor?
The three-phase synchronous motor is a unique and specialized motor. As the name suggests, this motor runs at a constant speed from no load to full load in synchronism with line frequency. … This attraction exerts a torque on the rotor and causes it to rotate at the synchronous speed of the rotating stator field.
What is a synchronous motor and how does it work?
Synchronous Motor Excitation
The synchronous motor is doubly fed electrical motor i.e it converts electrical energy to mechanical energy via magnetic circuit. Hence it comes under electromagnetic device. It receives 3 phase ac electrical supply to its armature winding and DC supply is provided to rotor winding.
Why synchronous motors are not self starting?
Above a certain size, synchronous motors are not self-starting motors. This property is due to the inertia of the rotor; it cannot instantly follow the rotation of the magnetic field of the stator. … Because of this action, the rotor will be subjected to an instantaneous torque in an anticlockwise direction.
What are the advantages of synchronous motor?
The advantage of using synchronous motor is the ability to control the power factor. An over excited synchronous-motor has leading power factor and is operated in parallel to induction motors thereby improving the system power factor. Speed remains constant irrespective of the loads in synchronous motors.
Where do we use synchronous motor?
Synchronous motors are normally used in applications in which a constant and precise speed is required. Typical applications of these low power motors are positioning machines. They are also used in robot actuators. Synchronous motors are also used in ball mills, watches, record players, and turntables.
How can a synchronous motor be self starting?
Answer: The synchronous motor itself does not have the ability to self-start. However, the addition of an additional winding known as damper winding (similar to squirrel cage motor) enables it to self-start. This damper winding is linked with the rotor, and works on the principle of induction motor.
What are the main parts of synchronous motor?
A synchronous motor is generally made up of two parts, a stator the stationary part of the machine that carries the armature winding in which the voltage is generated, and a rotor the rotating part of the machine that produces the main field flux.
Why does the synchronous motor run at synchronous speed?
This property is due to the inertia of the rotor; it cannot instantly follow the rotation of the magnetic field of the stator. Once the rotor nears the synchronous speed, the field winding is excited, and the motor pulls into synchronization.
How does a 3 φ synchronous motor start?
A three-phase synchronous motor has no starting torque. … Once up to speed, the rotor field can be excited with direct current and the rotor is, in effect, then dragged around at the same speed as the three-phase stator field.