Why the stator and rotor have different number of poles in SRM?
Table of Contents
- 1 Why the stator and rotor have different number of poles in SRM?
- 2 What is the relation between the number of poles of stator and rotor windings of a 3 phase induction motor?
- 3 What is the number of phases that can be used in 18 stator poles and 24 rotor poles SRM configuration How?
- 4 Where the rotor position sensor is located in switched reluctance motor?
- 5 How many Poles would the rotor of a 4 pole synchronous generator have?
- 6 What will happen if induction motor speed reaches synchronous speed?
- 7 Why does an induction motor have a number of Poles?
- 8 What is the force of repulsion between the rotor and stator?
Why the stator and rotor have different number of poles in SRM?
In order to rotate the SRM, the number of stator and rotor poles are different. If high speed is desired from the SRMs, the number of rotor poles must be smaller than number of stator poles, and if the high torque is desired, the number of rotor poles is selected to be close to the number of stator poles.
What is the relation between the number of poles of stator and rotor windings of a 3 phase induction motor?
The number of poles of rotor are kept same to the number of poles of the stator. The rotor is always wound 3 phase even if the stator is wound two phase. The three phase rotor winding is internally star connected.
What is the relationship between the number of poles on the stator and the number of poles on the rotor for a synchronous motor?
Synchronous speed For a 3-phase motor, if you count a total of 12 coil groups, it has 4 magnetic poles. For a 12-pole 3-phase machine, there will be 36 coils. The number of magnetic poles in the rotor is equal to the number of magnetic poles in the stator.
What is the effect of number of poles on speed of induction motor?
The main thing to understand is that increasing the number of poles reduces the motor’s synchronous speed. A 2 pole motor on 60 hz power has a synchronous speed of 3,600 rpm. For an induction motor, that will typically drop by a “slip” percentage, typically about 4\% to 3,450 rpm.
What is the number of phases that can be used in 18 stator poles and 24 rotor poles SRM configuration How?
The number of phases is 4, yielding an angular step of 5 degrees.
Where the rotor position sensor is located in switched reluctance motor?
Rotor position sensor which is mounted on the shaft of SRM, provides signals to the controller about the position of the rotor with reference to reference axis.
What will happen if we increase the air gap in the induction motor *?
Detailed Solution. If the air gap of an induction motor increases, 1) The permeability of the magnetic circuit rotor-to-stator will decrease. 2) The magnetizing inductance of the motor thus decreases.
How many pole pairs does the rotor have?
The rotor is composed of windings which are connected to a mechanical commutator. In this case the rotor has three pole pairs. The opposite polarities of the energized winding and the stator magnet attract and the rotor will rotate until it is aligned with the stator.
How many Poles would the rotor of a 4 pole synchronous generator have?
This generator (or motor) has four poles at all times, two South and two North. Since a four pole generator will only take half a revolution per cycle, it will obviously make 25 revolutions per second on a 50 Hz grid, or 1500 revolutions per minute (rpm)….
| Pole number | 50 Hz | 60 Hz |
|---|---|---|
| 12 | 500 | 600 |
What will happen if induction motor speed reaches synchronous speed?
Slip. Slip is strongly associated with synchronous speed. If the motor turned at the same RPM as the magnetic field, there would be no relative motion between the rotor and the field. Therefore, no current would be induced into the rotor, and no magnetic field would be created to cause it to turn.
What is the effect for number of poles in motor?
When the number of poles and the number of slots increases, a large torque can be obtained and the torque pulsation also decreases. The pole represents the number of permanent magnet poles for the rotating rotor, and a motor with one pair of N pole/S poles is called a two-pole motor.
What will happen if the stator poles are not equal to rotor poles?
Of stator poles are not equals to the rotor poles then there will produce huge airgap power as loss. So that the efficiency of the motor will decrease. The motor will hesitate to start. In an induction motor the rotor is typically of a squirrel cage construction. That means that there are no specific poles in the rotor.
Why does an induction motor have a number of Poles?
Ordinary induction motors don’t have a specific number of poles in the rotor, called a “squirrel cage”, and the rotor slits are angled to make sure they don’t act like discrete poles. Originally Answered: Why are the number of poles of rotor and stator of a motor be equal?
What is the force of repulsion between the rotor and stator?
Where K is some constant. Thus the force of repulsion (in clockwise direction) between the rotor pole N1 and stator pole N will be equal in magnitude to the force of attraction (in anticlockwise direction) between the rotor pole N2 and stator pole S.
What is the net torque due to the interaction of rotor poles?
Thus the force of repulsion (in clockwise direction) between the rotor pole N1 and stator pole N will be equal in magnitude to the force of attraction (in anticlockwise direction) between the rotor pole N2 and stator pole S. Thus the net torque due to the interaction of rotor poles N1 & N2 and stator poles N & S will be zero.