What do i need to explain to show how an induction motor works?

[delfick]

hi all (hopefully friendly) people...

In my year 12 physics class, i have been given a report on AC induction motors to complete.

Basically the requirement is the explain the physics behind it, how it works, why, etc

Can someone give me a list of things that i should cover as i am finding it very hard to try and find what it is i should explain so that i cover it fully...(if that makes any sense)

either that or some links that will get me started or something...

thnx for help

 

[Nomy-the wanderer]

http://hyperphysics.phy-astr.gsu.edu/HBASE/magnetic/indmot.html

How about that for a starter??

 

[kyle8921]

To explain how an induction motor works, you will need to cover the following concepts:

1. Electromagnetism: The basic principle behind an induction motor is the interaction between electric currents and magnetic fields. This is the foundation of electromagnetism, which explains how electric currents can generate magnetic fields and vice versa.

2. Alternating current: An induction motor operates using alternating current (AC) which constantly changes direction. This is different from direct current (DC) which flows in one direction only. You will need to explain the difference between AC and DC and why AC is used in induction motors.

3. Rotating magnetic fields: In an induction motor, the stator (the stationary part of the motor) creates a rotating magnetic field. This is achieved by using a set of three-phase windings, which are energized in sequence to create a rotating magnetic field.

4. Induced currents: When a conductor (such as the rotor in an induction motor) is placed in a rotating magnetic field, it will experience a changing magnetic flux. This changing magnetic flux induces a current in the conductor, according to Faraday's law of electromagnetic induction.

5. Synchronous speed: The speed at which the rotating magnetic field in the stator is generated is known as the synchronous speed. This speed is determined by the frequency of the AC power supply and the number of poles in the motor.

6. Slip: In an induction motor, the rotor will always rotate at a slightly slower speed than the synchronous speed. This difference in speed is known as slip and is necessary for the motor to operate.

7. Rotor design: There are two main types of rotor designs in induction motors - squirrel cage and wound rotor. You will need to explain the differences between these designs and how they affect the operation of the motor.

8. Torque production: An induction motor produces torque through the interaction between the rotating magnetic field and the induced currents in the rotor. This torque is what allows the motor to rotate and do useful work.

9. Efficiency and power factor: Induction motors are highly efficient machines, but their efficiency can be affected by factors such as slip, rotor design, and load. You will need to explain how efficiency and power factor are important considerations in the operation of an induction motor.

10. Applications: Induction motors are used in a wide range of applications, from household appliances to industrial machinery. You can discuss some common applications and how the principles of induction motors apply to these specific