## Electronics

Topics relate to HFSS, Maxwell, SIwave, Icepak, Electronics Enterprise and more

#### Ansys Maxwell – Inductance value simulation [HELP URGENT]

• Malnyr
Subscriber

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
Ansys Employee

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
Subscriber
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
Subscriber
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
Ansys Employee

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

Regards Navya
• Malnyr
Subscriber
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
Subscriber
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
Subscriber
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
Ansys Employee
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
Subscriber

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!