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Interpolation

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Dear all,

I'm encountering problems when using the Interpolation functions. I'm working on a couples "Rotating Machinery, Magnetic" and "Global ODEs and DAEs" model. The goal is to simulate an electrical machine with a PWM voltage supply.
When I define the voltage as a Global Variable using, for example, the expression "Vc = Vamp*cos(2*pi*f*t-4*pi/3)" everything works fine. However, when defining the voltage using interpolation functions COMSOL can't solve the ODE's I've imposed (these ODE's contain the voltages). The error message is:
Failed to evaluate variable
- Variable: Vc
- Global scope
Failed to evaluate expression
- Expression: Vc-R*mod1.Ic2-L*mod1.Ic2t-mod1.EMF_C2
Anyone an idea on how to solve this?

BR,
Bert Hannon

2 Replies Last Post 09.09.2016, 06:00 GMT-4

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Posted: 9 years ago 24.02.2015, 11:05 GMT-5
This problem has been fixed. There seemed to be a problem with the time dependency in the ODEs.
This problem has been fixed. There seemed to be a problem with the time dependency in the ODEs.

Ravi Kumar Jujjuvarapu

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Posted: 8 years ago 09.09.2016, 06:00 GMT-4
Dear Bert

Could you please share/advice me about the issue and how solved it. I am having same problem, actually i am trying to couple electric circuit PWM inverter model with Induction Motor multiphysics model.

Your advice and guidance on this will be much appreciated. Please check attached .mph file.

Thanks and Regards
Dear Bert Could you please share/advice me about the issue and how solved it. I am having same problem, actually i am trying to couple electric circuit PWM inverter model with Induction Motor multiphysics model. Your advice and guidance on this will be much appreciated. Please check attached .mph file. Thanks and Regards

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