LTSPICE chokes modelling

Thread Starter

FuseFuse

Joined Feb 8, 2017
25
Good morning,
I'm trying to work on a model of an EMC common mode choke in LTspice (in the attachment).
It's a three phase choke and I need to define 6 external ports (nr. 1,3,5 at input side / nr. 2,4,6 at output side) and 3 internal ports (nr.7,8,9). Actually it seems there is some error with syntax, since this model crashes on a simple test circuit as sketched below
1641299468901.png
1641299579277.png
Ports 7,8,9 are internal nodes and don't need to be connected externally. Nevertheless, this model works only in case if 7,8,9 ports are not used.
Any tips on what's the issue about this modelling?
Thanks for your help.
 

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ericgibbs

Joined Jan 29, 2010
15,529
hi FF,
Do you have a simple wiring diagram showing the actual component configuration so that we can check the .net.?
E
 

Thread Starter

FuseFuse

Joined Feb 8, 2017
25
hi FF,
Do you have a simple wiring diagram showing the actual component configuration so that we can check the .net.?
E
Yes, sure. I attached it to this message. Ports and components naming is consistent with .sub file I already shared in the previous post.

Thanks
 

Attachments

eetech00

Joined Jun 8, 2013
3,158
Good morning,
I'm trying to work on a model of an EMC common mode choke in LTspice (in the attachment).
It's a three phase choke and I need to define 6 external ports (nr. 1,3,5 at input side / nr. 2,4,6 at output side) and 3 internal ports (nr.7,8,9). Actually it seems there is some error with syntax, since this model crashes on a simple test circuit as sketched below
View attachment 256814
View attachment 256817
Ports 7,8,9 are internal nodes and don't need to be connected externally. Nevertheless, this model works only in case if 7,8,9 ports are not used.
Any tips on what's the issue about this modelling?
Thanks for your help.
Hi

two problems:

1. The subckt statement is missing a "params:" keyword following the pin mapping. The "params:" keyword informs spice that the items following it are parameters.
2. Parameters are missing for rs1_b, rs2_b, rs3_b

Corrected file "Choke_model_7-x.sub" is attached.
 

Attachments

Thread Starter

FuseFuse

Joined Feb 8, 2017
25
Hi

two problems:

1. The subckt statement is missing a "params:" keyword following the pin mapping. The "params:" keyword informs spice that the items following it are parameters.
2. Parameters are missing for rs1_b, rs2_b, rs3_b

Corrected file "Choke_model_7-x.sub" is attached.
Thank you very much. Now it's working.
I wonder why this model works without "params:" in case if 6 ports only are defined.

I also noticed that the model works only on condition that DKIH-3352-16D5 naming in line .subckt DKIH-3352-16F5 1 2 3 4 5 6 7 8 9 params: is not modified. For example, if I change it to DKIH-3352-16F5, the follow error appears
1641372571042.png
Can you explain me why?
 

eetech00

Joined Jun 8, 2013
3,158
Thank you very much. Now it's working.
I wonder why this model works without "params:" in case if 6 ports only are defined.
The "params:" keyword is only needed if there are parameters defined on the .subckt line. This is the correct syntax.
Some spice programs do not enforce use of this keyword. However, to ensure compatibility, the keyword should be used.
Why do think the keyword shouldn't work without parameters?

I also noticed that the model works only on condition that DKIH-3352-16D5 naming in line .subckt DKIH-3352-16F5 1 2 3 4 5 6 7 8 9 params: is not modified. For example, if I change it to DKIH-3352-16F5, the follow error appears
View attachment 256897
Can you explain me why?
The error message is telling you there is no definition for "DKIH-3352-16F5" that can be located in the default locations or in your model definition file "Choke_Model_7.sub". The message is accurate. There is no definition for that name in your model definition file.
 
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