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connecting CIR to MF physic

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Hello,
I'm a quite new Comsol user, and I have some questions.
I want to excite a coil (mf physic) with an electrical circuit (cir physic) in a 3 D model. I have put a boundary feed and ground conditions for the coil. The boundary feed is defined with a current (circuit) coil excitation.
The cir circuit is composed of a voltage sine source in serie with a resistance, capacitance and the external I Vs U device (with Coil voltage (mf/stdc) choose in the voltage list).
I compute with a time dependent solver, no problem of convergence but no coupling with the mf physic! I can just measure currents and voltages in cir circuit. Why?
I found in Comsol doc a sentence but I don't understand what I suppose to do to connect properly physics.

"Except for when coupling to a circuit terminal or circuit port, the current flow variable must be manually coupled back in the electrical circuit to the context of the voltage measurement"

I have only two way to connect my electrical circuit, with external I Vs U and external V Vs I, respectively with boudary feed current (circuit) and boundary feed voltage circuit, giving the possibility to fixe coil voltage or coil current in the external device. I try the 2 possibilities with no success.

I join a simple model to illustrate things,

I need help, someone know how to connect this ?

Thank you

Julien


2 Replies Last Post Nov 22, 2012, 3:55 a.m. EST
Andrea Ferrario COMSOL Employee

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Posted: 1 decade ago Nov 22, 2012, 3:38 a.m. EST
Hello Julien,

The 3D Single Turn Coil Domain works more or less like a "local" version of the Magnetic and Electric Fields physics, so it is likewise not applicable in Time Dependent studies. It can be used in Stationary and Frequency studies only.

--
Andrea Ferrario
Electromagnetics Group
COMSOL AB
Hello Julien, The 3D Single Turn Coil Domain works more or less like a "local" version of the Magnetic and Electric Fields physics, so it is likewise not applicable in Time Dependent studies. It can be used in Stationary and Frequency studies only. -- Andrea Ferrario Electromagnetics Group COMSOL AB

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Posted: 1 decade ago Nov 22, 2012, 3:55 a.m. EST
Thank you for the quick response Andrea,

There is a tutorial model called inductor_in_circuit.mph where mf and cir are coupled together. I join the model
The difference is that the tutorial is in 2 D axy and mine in 3D.

If 3D is the problem, can I visualize current and voltage in function of time (1/freq) in frequency domain? I think not.

Julien
Thank you for the quick response Andrea, There is a tutorial model called inductor_in_circuit.mph where mf and cir are coupled together. I join the model The difference is that the tutorial is in 2 D axy and mine in 3D. If 3D is the problem, can I visualize current and voltage in function of time (1/freq) in frequency domain? I think not. Julien

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