- 1 Why are short Chorded windings employed in induction motor?
- 2 What are the advantages of distributed windings and fractional pitch windings?
- 3 What are the advantages of short pitched winding?
- 4 Which type of winding is used in synchronous motor?
- 5 Why synchronous motors are not self starting?
- 6 What is slot angle?
- 7 What distributed windings?
- 8 What is the difference between full pitch and short pitch?
- 9 What are the advantages of pitching or chording?
- 10 What are the advantage and disadvantage of short pitched winding?
- 11 What is short pitch?
- 12 What is single layer winding?
- 13 Why do we use synchronous motors?
- 14 What are the advantages of synchronous motor?
- 15 What are the main parts of synchronous motor?
Why are short Chorded windings employed in induction motor?
Short pitch winding improve the waveform of generated emf i.e. generated emf can be made to approximate to a sine wave more easily and the distorting harmonics can be reduced or totally eliminated. In order to compensate for this reduction in Generated EMF, more number of turns and therefore more copper is required.
What are the advantages of distributed windings and fractional pitch windings?
Advantages of Distributed Winding: It reduces harmonics present in the generated emf which also improves the sine waveform. It reduces armature reaction and improves cooling. The coil is distributed over the slots, so the core (copper and iron) is fully used. It improves the mechanical strength of the winding.
What are the advantages of short pitched winding?
The advantages of short pitch winding are: Waveform of induces EMF can be approximately made into a sine wave and losses due to harmonics can be totally reduced or eliminated. Conductor material, copper, is saved in the back and in the front due to less copper span.
Which type of winding is used in synchronous motor?
The main purpose of using Damper winding in synchronous Machine is to provide starting torque and eliminate damping or hunting. The damper winding is used in Synchronous Motor to provide starting torque and the damper winding is used in the synchronous alternator to eliminate damping or hunting.
Why synchronous motors are not self starting?
Above a certain size, synchronous motors are not self-starting motors. This property is due to the inertia of the rotor; it cannot instantly follow the rotation of the magnetic field of the stator. Once the rotor nears the synchronous speed, the field winding is excited, and the motor pulls into synchronization.
What is slot angle?
Slotted angle (also sometimes referred to as slotted angle iron) is a system of reusable metal strips used to construct shelving, frames, work benches, equipment stands and other structures.
What distributed windings?
For obtaining smooth sinusoidal emf wave from, conductors are placed is several slots under single pole. This armature winding is known as distributed winding. It also reduces harmonic emf and so waveform is improved. It also diminishes armature reaction.
What is the difference between full pitch and short pitch?
In a full pitch coil, the coil span will be 180° electrical ( equal to pole pitch ). In a short pitch coil, the coil span will be (180 – α)° electrical ( α = angle by which coils are short-pitched and always less than pole pitch ).
What are the advantages of pitching or chording?
Advantages of Short Pitch Coil or Chording It shortens the ends of the winding and, therefore, there is a saving in the conductor’s material. It reduces the effects of distorting harmonics and thus the waveform of the generated voltage is improved and making it a sine wave.
What are the advantage and disadvantage of short pitched winding?
Disadvantages of Short Pitch Coil: The disadvantages of using short-pitch winding is that, the total voltage around the coils is somewhat reduced. In order to compensate for this reduction in Generated EMF, more number of turns and therefore more copper is required.
What is short pitch?
If the angular distances between the two coil sides are less than one pole pitch, it is termed short pitch or fractional pitch coil. The coil span or coil pitch for short or fractional pitch coil is less than 180 electrical degree. In such coils, the two coil sides are not under the poles.
What is single layer winding?
When each side of a coil occupies a slot completely without any other coil lying on top of it and the number of coils equals half the number of slots, the winding is known as single layer winding . Concentric winding or chain winding types are common and in this type of winding, short-pitched coils cannot be used.
Why do we use synchronous motors?
usually, synchronous motors are used for applications where precise and constant speed is required. While used in high power industrial sizes, these motors perform two important functions. One is as an efficient means of converting AC energy into mechanical energy and the other is Power factor correction.
What are the advantages of synchronous motor?
The advantages of the synchronous motor are the ease with which the power factor can be controlled and the constant rotational speed of the machine, irrespective of the applied load. Synchronous motors, however, are generally more expensive and a d.c. supply is a necessary feature of the rotor excitation.
What are the main parts of synchronous motor?
The Construction of Synchronous Motors A synchronous motor is generally made up of two parts, a stator the stationary part of the machine that carries the armature winding in which the voltage is generated, and a rotor the rotating part of the machine that produces the main field flux.