There are 5 types of starting in induction motors:
1) resistance variable method
2) auto transformer method
3) slip ring induction motor method
Squirrel cage induction motor using two types of starting methods
1.Direct on line starter
2.Star delta starter
its not a self starting motor, In this speed of a motor is constant so it is also know as synchronous speed.it can practised by methods,
1.using pony motors
2.using damper winding
3.using slip ring motor
4.using small d.c motor to coupling it
It starts all by itself because the 3-phase magnetic field inside is continuously rotating.
Starting of the synchronous motor using the DC generator creates a magnetic field.
In synchronous motor hunting can be minimized using flywheel to the shaft .
As per the operating principle of the Synchronous motor, due to continuous & rapid rotation of stator poles,the rotor is subjected to a torque which is rapidly reversing i.e. in quick succession,the rotor is subjected to torque which tends to move it first in one direction & then in the opposite direction.Owing to its large inertia,the rotor cannot instataneously respond to such quickly-reversing torque,with the result that it remains stationary or in other words it is not self starting.
The induction motor is the special kind of motor which runs below and above the synchronous speed. which the synchronous motor runs nearly equal the synchronous speed. The operation of synchronous motor runs with dc field excited hence separate dc field current is given to the field circuit. where as the induction motor the field and main field is drawn from the same supply hence no excitation is required. But due to this separate starting mechanism has to be required in case of the single phase induction motor.
Principle of synchronous motor is as given below:"when a 3 phase winding is fed by a 3 phase supply, then a magnetic flux of constant magnitude but rotating at synchronous speed, is produced."
mainly alternator,synchronous motor comes under the synchronous machine.a synchronous motor is not a self starting motor.if a synchronous motor moves with more than synchronous speed then it acts as a synchronous generator.
Starting of the synchronous motor using the DC generator creates a magnetic field.
True synchronous mode and self control mode
In synchronous motor hunting can be minimized using flywheel to the shaft .
a synchronous condenser is over excited synchronous motor under no load
A synchronous motor runs at synchronous speed, so there is no slip, or zero slip.
As per the operating principle of the Synchronous motor, due to continuous & rapid rotation of stator poles,the rotor is subjected to a torque which is rapidly reversing i.e. in quick succession,the rotor is subjected to torque which tends to move it first in one direction & then in the opposite direction.Owing to its large inertia,the rotor cannot instataneously respond to such quickly-reversing torque,with the result that it remains stationary or in other words it is not self starting.
The synchronous motor is made self starting by providing a special winding on the rotor poles, known as damper winding or squirrel cage winding. AC supply given to the stator produces a rotating magnetic field which causes the rotor to rotate, therefore, in the beginning synchronous motor provided with damper winding starts as a squirrel cage induction motor. The exciter moves along the rotor. When the motor attains about 95%of synchronous speed, the rotor winding is connected to exciter terminals and the rotor is magnetically locked by the rotating field of the stator and the motor runs as a synchronous motor. While starting a synchronous motor, the field winding must be shorted through a suitable resistance so that the induced voltage is distributed throughout the whole winding and no part is subjected to the high voltage induced in the entire winding.
A synchronous motor runs at synchronous speed, so there is no slip, or zero slip.
where can I buy a TYC50-12 synchronous motor for a fibre optic christmas tree
Reduce the speed of the stator magnetic field.Use an external prime mover to accelarte the synchronous motor upto synchronos speed.Use damper windings.
The induction motor is the special kind of motor which runs below and above the synchronous speed. which the synchronous motor runs nearly equal the synchronous speed. The operation of synchronous motor runs with dc field excited hence separate dc field current is given to the field circuit. where as the induction motor the field and main field is drawn from the same supply hence no excitation is required. But due to this separate starting mechanism has to be required in case of the single phase induction motor.