Re: leakage inductance

["joeriel" <joer@xxxxxxxxxxxx>]

--- In femm@xxxx, "salloker" <michael.salloker@xxxx> wrote:
> In the FEMM manual is a good description how to calculate the self 
> and the mutual inductance of coils. 
> 
> In addition I am searching for a way to calcualate the leakage 
> inductance of two coils. Does anyone have experience doing this?

Doing so is straightforward. For a two-winding transformer
with one turn each, the leakage inductances are

Lleak1 = Ls1 - Lm
Lleak2 = Ls2 - Lm

where 
Lleak1 is the leakage inductance of winding one,
Lleak2 is the leakage inductance of winding two,
Ls1 is the self inductance of winding one,
Ls2 is the self inductance of winding two, and
Lm is the mutual inductance.

The model to use is a T-network:
Lleak1 is the left-top segment (of the T)
Lleak2 is the right-top segment,
Lm is the vertical segment.

To model np primary turns and ns secondary turns,
connect 
the 1 turn winding of an ideal np:1 transformer
to the left side of the T
and connect
the 1 turn winding of an ideal 1:ns transformer
to the right side of the T.

Joe Riel