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Current in Induction heating (Peak or RMS)?

Posted 23 août 2012, 08:39 UTC−4 Low-Frequency Electromagnetics, Heat Transfer & Phase Change Version 4.2a 6 Replies

Abhishek Basak
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Hello,

When solving using the Induction Heating solver, can anybody confirm if the "Current Excitation" in the "Coil Group Domain" is peak or RMS? I have a suspicion that the value to be specified is the PEAK value, since the expression for the coil power has a factor of 1/2. Can anybody confirm?

Abhishek
6 Replies Last Post 31 août 2012, 17:45 UTC−4
Abhishek Basak
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Posted: 1 decade ago 24 août 2012, 11:21 UTC−4
Anybody have any idea about this?? Please!!
Anybody have any idea about this?? Please!!
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 25 août 2012, 20:27 UTC−4
Hi

which solver do you use ? if it's the harmnic or frequency domain, indeed you define an (0-peak) amplitude excitation, and then usually the average power has a factor 1/2 ... no ?

The best is always to make a very simple model you can write out analytically, to validate your undersanding of COMSOLs behaviour (and this before you validate COMSOL's results ;)
--
Good luck
Ivar
Hi which solver do you use ? if it's the harmnic or frequency domain, indeed you define an (0-peak) amplitude excitation, and then usually the average power has a factor 1/2 ... no ? The best is always to make a very simple model you can write out analytically, to validate your undersanding of COMSOLs behaviour (and this before you validate COMSOL's results ;) -- Good luck Ivar
Abhishek Basak
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Posted: 1 decade ago 29 août 2012, 06:01 UTC−4
Hello,

I am using the "Induction Heating" Model as given in COMSOL 4.2a. I think it uses Harmonic analysis for the ACDC part.

Any idea if the Coil Current to be specified is the peak or rms?

Regards,
Abhishek
Hello, I am using the "Induction Heating" Model as given in COMSOL 4.2a. I think it uses Harmonic analysis for the ACDC part. Any idea if the Coil Current to be specified is the peak or rms? Regards, Abhishek
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 29 août 2012, 20:56 UTC−4
Hi

for the harmonic solver the forces you apply are the amplitude (0-pk) of the "sinus" type harmonic excitation you desire
you have then also some rms value outputs, check the equatoions of COMSOL and the doc

--
Good luck
Ivar
Hi for the harmonic solver the forces you apply are the amplitude (0-pk) of the "sinus" type harmonic excitation you desire you have then also some rms value outputs, check the equatoions of COMSOL and the doc -- Good luck Ivar
Abhishek Basak
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Posted: 1 decade ago 31 août 2012, 04:59 UTC−4
Hello Ivar,

Thanks! .. I also thumbed through the induction heating example again (www.comsol.com/showroom/gallery/148/), and I noticed that the "Current Amplitude" is mentioned. So as you said, the peak current needs to be specified.

Also, I noticed that the coil voltage output can be obtained by multiplying the specified current with the coil impedance. Just for an example (from one of my analysed cases):

Coil current (Specified): 250 A (i.e. since no phase is mentioned, so its equivalent to 250exp(0*i), i.e. 250 + 0i A)
Coil impedance (Ω): 0.0225+0.76284i (As output from comsol)
Coil voltage (V): 5.62594+190.71109i (As output from comsol)

As we can see (250 + 0i)*(0.0025+0.76284i) = 5.625 + 190.71i V (same as comsol output)

Being am a mechanical engineer, I could not make much sense of the theory manual :-), but thanks for your help :-)

Regards,
Abhishek Basak
Hello Ivar, Thanks! .. I also thumbed through the induction heating example again (www.comsol.com/showroom/gallery/148/), and I noticed that the "Current Amplitude" is mentioned. So as you said, the peak current needs to be specified. Also, I noticed that the coil voltage output can be obtained by multiplying the specified current with the coil impedance. Just for an example (from one of my analysed cases): Coil current (Specified): 250 A (i.e. since no phase is mentioned, so its equivalent to 250exp(0*i), i.e. 250 + 0i A) Coil impedance (Ω): 0.0225+0.76284i (As output from comsol) Coil voltage (V): 5.62594+190.71109i (As output from comsol) As we can see (250 + 0i)*(0.0025+0.76284i) = 5.625 + 190.71i V (same as comsol output) Being am a mechanical engineer, I could not make much sense of the theory manual :-), but thanks for your help :-) Regards, Abhishek Basak
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 31 août 2012, 17:45 UTC−4
Hi

on my side being a Physicist and Systems Engineer I have learned most of my systems approaches by studing the manuals for all items I encounter, in the beginning you feel overrun, but after some years you get used to it and you catch more than what you think, and its generally very useful ;)

--
Good luck
Ivar
Hi on my side being a Physicist and Systems Engineer I have learned most of my systems approaches by studing the manuals for all items I encounter, in the beginning you feel overrun, but after some years you get used to it and you catch more than what you think, and its generally very useful ;) -- Good luck Ivar

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