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The spatial distribution of the windings in the armature is designed in a way such that it produce a rotating field when a three phase source is applied to its terminals.
The field windings have a DC field applied to it and it is rotated mechanically by a prime mover. If the prime mover tried to rotate the synchronous machine at speed higher than its synchronous value then the power output of the generator will increase and this causes the speed to "lock" again to the synchronous one.
If the prime mover applied less torque then the machine will slow down but the power output will decrease DUE TO DECEASE in the applied torque and this cause the machine to "lock" again to synchronous speed of the grid.
The same principle can be applied to synchronous motors except that torque is negative (i.e. the prime mover is applying negative torque)
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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
What in slip speed control?
slip speed control refers to induction machines s=(synchronous speed-motor speed)/synchronous speed by varying slip the machine can be either be operate in generated mode or motor mode
What is synchronous reference frame?
It has been shown that the speed of rotation of the d.q axes can be arbitrary although there are three preferred speeds or reference frames as follows: (a) the stationary reference frame when the d,q axes do not rotate; (b) the synchronously rotating reference frame when the d,q axes rotate at synchronous speed; (c) the rotor reference frame when the d,q axes rotate at rotor speed.
Why is a synchronous speed motor considered a constant speed motor?
synchronous motor is a constant speed motor because it will only run at a synchronous speed or not at all.the speed can be changed by changiing the frequency only ns=120f/p
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.
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.
Which motor rotate above synchronous speed?
An induction motor rotating at higher than synchronous speed would be generating power, thus would be a generator. No motor operating as a motor runs above synchronous speed.
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
What in slip speed control?
slip speed control refers to induction machines s=(synchronous speed-motor speed)/synchronous speed by varying slip the machine can be either be operate in generated mode or motor mode
What is the name of electric motor in which both rotor and stator fields rotate with same speed?
only synchronous motor
What is synchronous reference frame?
It has been shown that the speed of rotation of the d.q axes can be arbitrary although there are three preferred speeds or reference frames as follows: (a) the stationary reference frame when the d,q axes do not rotate; (b) the synchronously rotating reference frame when the d,q axes rotate at synchronous speed; (c) the rotor reference frame when the d,q axes rotate at rotor speed.
Why alternator are called synchronous generator?
Because it rotates at a constant (i.e.synchronous speed ) no matter whats the load on alternator.For instance if its a 2 pole machine it will rotate at 3000 rpm to produce a frequency of 50 Hz in India.
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
What is a synchronous motor?
Synchronous motors are those that run only at Synchronous speed ie.. constant speed.
Why the no of poles are less in induction machine compared to synchronous machine?
The number of poles determines the speed a machine has to turn (RPMs). The more poles, the slower the machine can turn. I don't believe your statement is true. I've seen synchronous generators, for example, that turn at 1200 RPMS, and induction motors that turn at ~1800RPMs.
Why do you use induction generators in wind generation rather than synchronous generators?
If you use synchronous generator... you need rotor to rotate always in synchronous speed... practically it s not possible always to produce that speed by air flow... Air flow always varies...But using induction generator, you need to get speed to make slip as positive value.. it is always possible...so induction generator is best one..
Why is a synchronous speed motor considered a constant speed motor?
synchronous motor is a constant speed motor because it will only run at a synchronous speed or not at all.the speed can be changed by changiing the frequency only ns=120f/p
