Skin Effect in high frequency transformers.

[rahul91]

Hi,
In my welding machine power supply project,i am designing a high frequency transformer...The major issue that I am facing is with the winding losses,when it comes to 100KHz.... In the design, I am asked to avoid the use of Litz wires. So I have to go for some paralleling mechanisms...Is there any thumb rule for assuming the current density of transformer windings, when skin effects are taken into account...? Or do I have to exactly calculate the available winding diameter(including skin effect) and calculate the number of windings to be paralleled..?

Thanks in advance..

 

[FvM]

Skin depth at 100 kHz is about 0.2 mm. You can derive a rule of thumb for wire gauge in stranded conductors.

Secondly you have both skin and proximity effect. As a result, bundles of enamelled wire must be well stranded (also changing between inner and out layer in larger strands, like litz wire does) to achieve uniform current distribution.

Foil windings can be an alternative, but sheet thickness must be selected in aware of skin effect.

 

[rahul91]

Skin depth at 100 kHz is about 0.2 mm. You can derive a rule of thumb for wire gauge in stranded conductors.

Secondly you have both skin and proximity effect. As a result, bundles of enamelled wire must be well stranded (also changing between inner and out layer in larger strands, like litz wire does) to achieve uniform current distribution.

Foil windings can be an alternative, but sheet thickness must be selected in aware of skin effect.

Thanks Fvm..

 

[The Electrician]

Have a look here under the heading "Magnetics Design":

https://engineering.dartmouth.edu/inductor/papers.shtml