Learning Forum

[Jason C]

Hi experts,

I have some question about winding loss of planer transformer.

Below figures are my simulation model. 

as you can see the only different is the winding width is not the same, one is long and the other is short, and both have the same air gap.

As my understanding, if I want to reduce the DCR(Low frequency resistance) I can add the width of winding to reduce the DCR, from the simulation result, it is accuarte to reduce the RDC after I add the width on primary side winding (orange color) and secondary side winding (green color).

Figure 2 has more larger width than Figure1, so the DCR will be smaller that will reduce the power loss on winding.

below is my questions, after I check the loss from the MAXWELL result, although the RDC is reduced, but I find it also increase the Rac (high frequency resistance), so the AC loss is increased.

May I know how to explain this phenomenon?

[HDLI]

Hello Jason C,

      This AC copper loss is also based on skin effect, meshing and flux leakage in the slot. Could you increase mesh and consider skin depth? and also check flux density distribution in the slot?

HDLI

 

[Jason C]

Hi HDLI,

Thanks for your answer.
I have some setting problen when I try to consider the Skin Depth.

1. I need to set Skin Depth for every winding?
2. only need to use Calculate Skin depth?
3. In what situation I need to consider Skin depth
4. How do I know the Surface Triangle Length
5. 
   
   
   Jason

[HDLI]

Hello Jason,

      The skin depth is based on material conductivity and freqeuncy. Please check the equation and information of why and what causes the skin depth.

      Maxwell would provide a calculator to calculate skin depth in skin depth meshing operation. I suggest to use default value for surface triangle value, but you can modify it.

HDLI

[Jason C]

Hi HDLI,

Sorry, I modify my questions.

I know what is the skin depth, below see my updated quesitons below.

1. I draw the winding which width is 2Oz, so I think the skin depth is not very improtant, and I also try do use this function in the eddy current simulation. there is no big difference in there, I mean the Rac value. so I would like to know if the width is small enough I don't need to consider the skin depth, am I correct?
2. Could you tell me how to see the flux leakage impact on my winding? I have no idea about that.

 

Jason

[HDLI]

Hello Jason,

     If the width is smaller than the skin depth, the skin effect would not be big, so we could ignore it and do not need skin depth meshing.

     You could check the current density distribution to see the eddy current effect, to determine where the leakage flux impact is.

HDLI