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A synchronous generator generally requires DC power supplied to the rotor winding to make it into an electromagnet. As the rotor spins, a voltage will be induced in the stator windings (the stationary windings).
A synchronous generator needs something to supply this initial DC power to the rotor, so it may be deemed to not be "self starting". "Self starting" may have several different interpretations, though. A "black start" generator could be deemed as being self starting, even though this initial power is (usually) supplied by a set of batteries. Many generators pull this power from the power grid, so if the grid is not energized (black start conditions), these generators cannot start until at least part of the power grid is put back in service with another generator.
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Drawing of speed-torque curve for synchronous machine?
Theoritical torque speed curve for a synchronous machine will be a vertical line located vertical to the synchrounous speed at x axis, from starting torque to stalling torque value. This is because theoritically synchronous motors are not self starting. Practically however they start as induction motors and at near synchrounous speed the excitation is switched on. Anand Sekhar
How does the starting of synchronous motor using dc generator as a load work-?
Starting of the synchronous motor using the DC generator creates a magnetic field.
Why synchronous motor is not a self starting motor?
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.
Why a machine should run with synchronous speed?
A synchronous motor is not self starting.However when it is provided with some prime mover ,which rotates it up to 80% of sync. speed,then it continues to rotate at sync.speed even after prime mover is removed.It happens so because rotor poles are locked with rotating magnetic field and hence the speed is always synchronous.
Applications of synchronous motor?
It is used in variety of applications such as... · Machine Tools such as a ball mill · Motor generator sets · Synchronous clocks · Timing devices · Synchronous condensers to condition electrical power · Record players · Robotics
What is synchronous machein?
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.
Drawing of speed-torque curve for synchronous machine?
Theoritical torque speed curve for a synchronous machine will be a vertical line located vertical to the synchrounous speed at x axis, from starting torque to stalling torque value. This is because theoritically synchronous motors are not self starting. Practically however they start as induction motors and at near synchrounous speed the excitation is switched on. Anand Sekhar
Why is the frequency of a synchronous generator locked into its rate of shaft rotation?
By definition a synchronous generator must be synchronous. If it is not "locked in" it is not a synchronous generator, but an induction machine.
What is emf equation for synchronous machine?
ediot
Speed control method for synchronous motor?
True synchronous mode and self control mode
How does the starting of synchronous motor using dc generator as a load work-?
Starting of the synchronous motor using the DC generator creates a magnetic field.
What do you mean by synchronous watt?
It is that torque which at the synchronous speed of the machine under consideration would develop a power of 1 watt
Why synchronous motor is not a self starting motor?
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.
Why a machine should run with synchronous speed?
A synchronous motor is not self starting.However when it is provided with some prime mover ,which rotates it up to 80% of sync. speed,then it continues to rotate at sync.speed even after prime mover is removed.It happens so because rotor poles are locked with rotating magnetic field and hence the speed is always synchronous.
How is the synchronous motor made 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.
How can you simulate the synchronous machine using pscad?
drag and drop and run
What has the author Cristian Anghel written?
Cristian Anghel has written: 'Sensorless flux vector control for a permanent magnet synchronous machine with cylindrical rotor under severe starting conditions'
