How to design a single phase induction motor

[AlexiaIoannou]

Hi everyone...
I have to design a single phase induction motor.
I have some questions and it would be great if you could help me. The parameters I have for the design of the motor are: rated power, rated voltage, frequency, rated speed, power factor, efficiency, full load current and full load torque.
I need some information of how to calculate other parameters, such as flux density, core length, air gap, size of both stator and rotor and their slots etc. I have found some equations for calculating all these for a 3 phase induction motor and I wonder if I can use them for the singe phase induction motor too.
I really appreciate your help , thank you very much!

 

[Hesch]

I have found some equations for calculating all these for a 3 phase induction motor and I wonder if I can use them for the singe phase induction motor too.

I don't know as I have not seen your equations.

As for a single phase motor you need only one (primary) winding. The motor can run, but it cannot start because it does not know in which direction to start. ( You can only induce a magnetic field in one dimension, which leaves no "space" to create angles ).

Therefore you must have an extra "starting coil" that has an electrical angle of say 90° as to the primary winding. This angle is provided by connecting a capacitor in series with the starting coil, thereby making a current phase shift in the starting coil and a "second dimension". So the coils in the single phase motor are not symmetrical as in the 3 phase motor, and thus (some of) the equations for the 3 phase motor cannot be used by the single phase motor.

how to calculate other parameters, such as flux density, core length, air gap, size of both stator and rotor and their slots etc.

This is very hard to explain in short.

 

[AlexiaIoannou]

How could i find these equations referring to the single-phase motor? Is there any paper or something?

 

[jim hardy]

Finding information is a process of learning key words and searching on them... like exploring a cave, you find pathways to unexpected rooms full of new things to learn.


http://www.ijera.com/papers/Vol2_issue1/AU021299304.pdf