End turns and end ring leakage inductances in machines ?

["marsupiofr" <marsupio@xxxxxxxxxxx>]

Dear sirs,

I'm currently dealing with end turns and end ring leakage inductances 
in squirrel cage induction machines. I found in books several 
analytical formulae but they are often esoteric and quite different 
from a reference to another reference. Does somebody have 
comprehensive analytical formulae concerning these extremity effects 
in machines (especially end-ring leakage inductance). By the way, I 
tried a small simulation (endring.fem in Files section) in FEMM : 
this is an axisymetric problem where I modelize a square end-ring 
carrying 1A (you can see the stator frame and rotor frame also). I 
want to calculate the inductance of this end-ring and I use integral 
A.j and I find 2.68e-7H. Do I make a mistake because I'm not familiar 
with axisymetric problem. There is certainly a problem also with the 
boundaries.

So, could you have a look at this simulation ? Thxs in advance.