About Synchronous Machine Design

Gibberish.....

dear solar eagle, thank you. because of you I learnt new word. if you would have cleared my doubt, that was most appreciable...

Ask your instructor to go over the equations again with you. He should be able to help clear up your doubts (questions).

See [for instance]:

Design of Rotating Electrical Machines by Juha Pyrhonen and others.

https://download.e-bookshelf.de/download/0003/9957/58/L-G-0003995758-0002511080.pdf

ch.6 Design Process of Rotating Electrical Machines

Or you can see:

file:///C:/Users/win7/Downloads/chapter_6.pdf

only for main dimensions.

link not opening

Copy the link directly in Google Chrome and it will open.

I can see where you are coming from and agree there is a bit of a mismatch.

However if you consider the power required to produce such a torque at the speeds you must accept that the power input to the machine must be in accordance with the torque and rpm of the machine.

I would suggest that a machine designed for the lower speed/torque figures could not absorb the power to produce the later torque and rpm figures.

Hence I consider just looking at the torque and rpm figures does not take into account all aspects of your deign.

Be easier to help if you told us what all your inputs stand for. I can guess some, and other posts suggest some, but what is Bav and Co? Why should Co = 11 Bav q Kw x 10-3? Is q the same as Q?

If Synchronous Motor of 60 Nm @ 100 RPM and 60 Nm @ 2000 RPM has to be designed, - did you mean @ 1000 RPM?

I think the OP is referring to:

http://ceme.ece.illinois.edu/seminars/CEME1109HarleyGeorgiaTech.ppt

I agree with pcchatur. According to Rudolf Richter [Electrical Machine vol. 2] the ratio rotor [ideal] length to the circumference part of one pole [p*Drotor/2p] λ=li/tau where tau=π*Drotor/2p 2p=number of poles λ=0.5*sqrt(p)

Since p=60*f/rpm f=frequency rpm=rotations per minute more rpm=less p[number of pole pairs] then less li-the rotor will be shorter and thicker.

Sorry, I did not finish the calculation and the result seems to be opposite:

li[gross rotor length]=0.5*sqrt(p)*pi/2/p*Drotor=pi/4/sqrt(p)*Drotor

Since p=60*f/rpm f=frequency rpm=rotations per minute more rpm=less p[number of pole pairs] then more li-the rotor will be longer and thinner.

As we see here output equation of the machine, it can be seen that the volume of this machine is directly proportional to output of the machine, the machine that is having higher speed will capable size and cost. If larger will be the specific loadings smaller is the size of the machine.