A synchronous electric motor is an AC motor in which the rotation of the shaft is synchronized with the frequency of the ACsupply current; the rotation period is exactly equal to an integral number of AC cycles. Synchronous motors contain electromagnetson the stator of the motor that create a magnetic field which rotates in time with the oscillations of the line current. The rotor turns in step with this field, at the same rate.
Another way of saying this is that the motor does not rely on "slip" under usual operating conditions, and as a result produces torque at synchronous speed. Synchronous motors can be contrasted with induction motors, which must slip in order to producetorque. The speed of the synchronous motor is determined by the number of magnetic poles and the line frequency.
Synchronous motors are available in sub-fractional self-excited sizes to high-horsepower direct-current excited industrial sizes. In the fractional horsepower range, most synchronous motors are used where precise constant speed is required. In high-horsepower industrial sizes, the synchronous motor provides two important functions. First, it is a highly efficient means of converting AC energy to work. Second, it can operate at leading or unity power factor and thereby provide power-factor correction.
It is that torque which at the synchronous speed of the machine under consideration would develop a power of 1 watt
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
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)
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
By definition a synchronous generator must be synchronous. If it is not "locked in" it is not a synchronous generator, but an induction machine.
It is that torque which at the synchronous speed of the machine under consideration would develop a power of 1 watt
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
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)
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
Synchronous motors are those that run only at Synchronous speed ie.. constant 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.
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.
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
By definition a synchronous generator must be synchronous. If it is not "locked in" it is not a synchronous generator, but an induction machine.
Number of poles and supply freqency determines speed of synchronous motor. For speed control of such motors Variable Freqency Drives(VFD) are used.
A synchronous motor runs at synchronous speed, so there is no slip, or zero slip.
A synchronous motor runs at synchronous speed, so there is no slip, or zero slip.