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Spice inport in 3D models

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Comsol Multiphysics example models include model using 2D circular symmetrical
simplified coil and a spice import to drive it. This example helps to find out how the node
numbers in spice description and the 2D model names can be made to match each others.
But how this can be done in 3D models ? Are there any example model to show this
or can this information be found in documentation ?

3 Replies Last Post 2012/02/09 9:16 GMT-5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 2012/02/02 7:45 GMT-5
Hi

from the moment you can define a port in 3D you can use a similar way, but 3D does not have all the advance multiturn BCs so you need to convert to a bulk single turn approach.

remains that excitation in 3D is more delicate as you need to loop your current correctly, therefore a current drive is sometimes easier if you are inside the volume, but Voltage drive on an outer surface should also be OK so long the current can loop around on the external surface

--
Good luck
Ivar
Hi from the moment you can define a port in 3D you can use a similar way, but 3D does not have all the advance multiturn BCs so you need to convert to a bulk single turn approach. remains that excitation in 3D is more delicate as you need to loop your current correctly, therefore a current drive is sometimes easier if you are inside the volume, but Voltage drive on an outer surface should also be OK so long the current can loop around on the external surface -- Good luck Ivar

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Posted: 1 decade ago 2012/02/09 9:05 GMT-5
In case of complete model the Spice import seem to be easy. Defining lumped port and setting its port name to
match node number in Spice net list.

What I'm looking after is the way the Spice import can be attached to simplified inductor model. Simplified
inductor can be defined to fit a domain (volume). So far I have seen in the demo examples the driving
voltage for such a simplified inductor has been defined in variables section of the model. But if Spice import
is to be used I guess the lumped port definition is needed again. But how in this case the lumped port
has to be created ? Thinking about for the example ecore_42 available from Comsol. A transformer with
primary and secondary coils mounted on E-core. There are no clear idea of what surfaces must be used
to source the input voltage or current to the primary. Are there any option the lumped port could be defined just by using surface numbers and make to match the Spice netlist numbers ? Are there any option the names
defined in the variables section could be made to match Spice net list names or numbers ?
In case of complete model the Spice import seem to be easy. Defining lumped port and setting its port name to match node number in Spice net list. What I'm looking after is the way the Spice import can be attached to simplified inductor model. Simplified inductor can be defined to fit a domain (volume). So far I have seen in the demo examples the driving voltage for such a simplified inductor has been defined in variables section of the model. But if Spice import is to be used I guess the lumped port definition is needed again. But how in this case the lumped port has to be created ? Thinking about for the example ecore_42 available from Comsol. A transformer with primary and secondary coils mounted on E-core. There are no clear idea of what surfaces must be used to source the input voltage or current to the primary. Are there any option the lumped port could be defined just by using surface numbers and make to match the Spice netlist numbers ? Are there any option the names defined in the variables section could be made to match Spice net list names or numbers ?

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 2012/02/09 9:16 GMT-5
Hi

I'm not sure I catch you fully, but when you define a lumped port it is attached to a Entity, and tehn you define a number name. In the Spice part you add a subnode for the U or I link and you attach it to the port desired

--
Good luck
Ivar
Hi I'm not sure I catch you fully, but when you define a lumped port it is attached to a Entity, and tehn you define a number name. In the Spice part you add a subnode for the U or I link and you attach it to the port desired -- Good luck Ivar

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