What is the relationship between frequency and synchronous speed?
What is the relationship between frequency and synchronous speed?
The synchronous speed of the motor can be changed by changing the number of poles or by changing the frequency. The machine which runs at synchronous speed is called synchronous machine….Synchronous speed Formula.
| No. of Poles | Frequency (50 Hz) | Frequency(60 Hz) |
|---|---|---|
| 2 | 3000 | 3600 |
| 4 | 1500 | 1800 |
| 6 | 1000 | 1200 |
| 8 | 750 | 900 |
What is the relation between frequency and synchronous speed of the alternator?
The synchronous speed is the speed of the revolution of the magnetic field in the stator winding of the motor. It is the speed at which the electromotive force is produced by the alternating machine. The Synchronous Speed is given by the relation shown below….Synchronous Speed.
| Number of Poles | Synchronous Speed NS in r.p.m |
|---|---|
| 12 | 500 |
What two factors determine synchronous speed?
The synchronous speed of an AC motor is determined by the frequency of the source and the number of poles.
What changes with respect to synchronous speed?
The frequency of the power supply and the number of poles of the machine determine the synchronous speed. In an induction motor, a changing magnetic field induces currents in the rotor, so the rotor will always rotate more slowly than the synchronous speed of the magnetic field in the stator.
How can we increase the speed of synchronous motor?
We can control the speed of the synchronous motor by changing the frequency of the supply to the motor.
How Hz affects speed of a motor?
V/Hz control maintains a constant ratio between voltage (V) and frequency (Hz). Varying the voltage frequency affects both the motor speed and the strength of the magnetic field. When the frequency is increased (for higher motor speed), the magnetic field decreases, and lower torque is produced.
How can the speed of synchronous motor be reduced?
Speed of synchronous motors can be controlled using two methods called open loop and close loop control. Open loop contol is the simplest scalar control method where motor speed is controlled by independent frequency control of the converter.