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Error in Variable Declaration

Posted Jul 2, 2018, 10:18 a.m. EDT Low-Frequency Electromagnetics Version 5.1 2 Replies

Sangeerth P
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The below post is related to an archived discussion

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I tried to simulate a structure similar to that of a transformer in which an inductor is wound over a iron core with an iron gap. I have attached the structure image for your perusal. When ever I use stationary solver I dont have any trouble. But coming to Time Dependent solver, I changed the coil nature to Multi-turn coil-Numeric as well as changed the source to Sine source.

I get the following error.

Failed to find consistent initial values. Segregated Step 1 Division by zero. Function: / Failed to evaluate variable. Variable: comp1.mf.mtcd1.Vind, Defined as: (((300comp1.mf.mtcd1.intmtcd(((comp1.mf.mtcd1.eCoilycomp1.mf.Ey)+(comp1.mf.mtcd1.eCoilxcomp1.mf.Ex))+(comp1.mf.mtcd1.eCoilzcomp1.mf.Ez)))comp1.mf.mtcd1.fl)comp1.mf.mtcd1.fA)/comp1.mf.mtcd1.area Failed to evaluate variable. Variable: comp1.mf.VCoil 1, Defined as: (comp1.mf.mtcd1.avemtcd(comp1.cir.IvsU1 i)comp1.mf.mtcd1.R)-comp1.mf.mtcd1.Vind Failed to evaluate variable. Variable: comp1.cir.IvsU1.V, Defined as: comp1.mf.VCoil 1 Failed to evaluate variable. Variable: comp1.cir.IvsU1 vsrc, Defined as: comp1.cir.IvsU1.V Failed to evaluate variable. Variable: comp1.cir.IvsU1 v, Defined as: comp1.cir.IvsU1 vsrc Failed to evaluate variable. Variable: comp1.cir.R1 p v, Defined as: comp1.cir.IvsU1 p v+(-comp1.cir.IvsU1 v) Failed to evaluate expression. Expression: comp1.cir.V1 v+comp1.cir.V1 n v+comp1.cir.R1 Rcomp1.cir.R1 i-comp1.cir.R1 p v Last time step is not converged. - Feature: Time-Dependent Solver 1 (sol1/t1)

Please help me mates. I am in need of this solution.

2 Replies Last Post Jul 7, 2018, 2:20 p.m. EDT
Linda
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Posted: 6 years ago Jul 5, 2018, 11:16 a.m. EDT

Hello Sangeerth,

I encountered a similar error message and this did the trick for me: https://www.comsol.de/support/knowledgebase/1127/

Maybe it helps yout too.

Regards, Linda

Hello Sangeerth, I encountered a similar error message and this did the trick for me: https://www.comsol.de/support/knowledgebase/1127/ Maybe it helps yout too. Regards, Linda
Sangeerth P
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Posted: 6 years ago Jul 7, 2018, 2:20 p.m. EDT

Hi Linda First I wish to thank you for your response. I have included with "Fully Coupled" Giving Max no. of iterations to be 16 But now I came with another error

Division by zero. - Function: / Failed to evaluate temporary symbolic derivative variable. - Variable: comp1.mf.Jex@VDN${comp1.mf.mtcd1.avemtcd@19} - Defined as: (comp1.mf.mtcd1.eCoilx300)(1/comp1.mf.mtcd1.area) Failed to evaluate temporary symbolic derivative variable. - Variable: comp1.mf.Jx@VDN${comp1.mf.mtcd1.avemtcd@19} - Defined as: (comp1.mf.mtcd1.eCoilx300)(1/comp1.mf.mtcd1.area) Failed to evaluate expression. - Expression: d(d((comp1.mf.d(-comp1.mf.Hxcomp1.mf.testcurlAx-comp1.mf.Hycomp1.mf.testcurlAy-comp1.mf.Hzcomp1.mf.testcurlAz+comp1.mf.Jxtest(comp1.mf.Adepx)+comp1.mf.Jytest(comp1.mf.Adepy)+comp1.mf.Jztest(comp1.mf.Adepz)))(dvol),{test@10}),{comp1.mf.mtcd1.avemtcd@19}) - Feature: Time-Dependent Solver 1 (sol1/t1)

This is some what different from the previous one. But I dont know why. Can U please help me. Regards Sangeerth P

Hi Linda First I wish to thank you for your response. I have included with "Fully Coupled" Giving Max no. of iterations to be 16 But now I came with another error Division by zero. - Function: / Failed to evaluate temporary symbolic derivative variable. - Variable: comp1.mf.Jex@VDN${comp1.mf.mtcd1.avemtcd@19} - Defined as: (comp1.mf.mtcd1.eCoilx*300)*(1/comp1.mf.mtcd1.area) Failed to evaluate temporary symbolic derivative variable. - Variable: comp1.mf.Jx@VDN${comp1.mf.mtcd1.avemtcd@19} - Defined as: (comp1.mf.mtcd1.eCoilx*300)*(1/comp1.mf.mtcd1.area) Failed to evaluate expression. - Expression: d(d((comp1.mf.d*(-comp1.mf.Hx*comp1.mf.testcurlAx-comp1.mf.Hy*comp1.mf.testcurlAy-comp1.mf.Hz*comp1.mf.testcurlAz+comp1.mf.Jx*test(comp1.mf.Adepx)+comp1.mf.Jy*test(comp1.mf.Adepy)+comp1.mf.Jz*test(comp1.mf.Adepz)))*(dvol),{test@10}),{comp1.mf.mtcd1.avemtcd@19}) - Feature: Time-Dependent Solver 1 (sol1/t1) This is some what different from the previous one. But I dont know why. Can U please help me. Regards Sangeerth P

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