Learning Forum

[Malnyr]

Hello everyone,

I'm doing a simulation on Ansys Maxwell of a spiral inductor. You can see the picture of the real inductor and its measured value with an RLCmeter is ~108µH.

[Navya C]

Check if the way you connected the coils in Maxwell is creating an opposing effect instead of aiding.
First, simulate a single coil and check the inductance value. This will confirm the above check point.

Regards Navya

[Malnyr]

Hi nchode, thank you for your answer.
Indeed, I tried what you told me and I got :
which is a bit higher than the Lthese/Lharold value found on Matlab value due to the presence of ferrite. Your point seems valid, the two coils interfere with each other.

[Malnyr]

Hi again, I continue to simulate and I don't know what I've changed because I don't find the same L anymore. I find a L equals to 12┬ÁH...

[Navya C]

Connect both the coils such that the current in both will in the same direction.

Regards Navya

[Malnyr]

Hi, with the single coil I have indeed 28┬ÁH. I understood why the inductance decreased and it happens when I activate the Eddy Current effect on the steel plate thus changing the inductance value :
Now, I will try to make the current go in the same direction in the case of the double coil.

[Malnyr]

Okay, so I simulated like this :
You can see the conduction path above. For the simulation I turned off the eddy effect for the steel plate :
to only find this inductance value :

[Malnyr]

Hi again, now I did this :
One entry and one output for each coil. And I measured the two self inductance and the mutual inductance :
Where we find again the inductance value for a single coil. Then to know the value of the whole, we need to apply the formula : Ltotal = L1+L2+2*Lmutual = 26.73+28.95+2*25.55 = 106.78┬ÁH which is exactly the measured value ! So I guess it's not possible to get the real inductance value directly because I tried in the previous message. Thank you for you help, I think I now undertand how it works !

[Navya C]

Yes, If you excited them as two coils. L(Current1, Current1) and L(Current2, Current2) are self inductances and L(current1, current2) is the mutual inductance
Glad that you got the correct result.

Regards Navya

[hyukjin lee]

Hello Malnyr,

Interesting work you did. what solution type did you use to compute the inductance? 

I am also trying to calculate the inducutance value at certain frequency but I am lost in setups. 

No idea how to set frequency as you did. a bit of help would be great

thank you!