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How to work in AC & DC combined electric fields

Posted 02.06.2019, 13:40 GMT-4 Electromagnetics, Low-Frequency Electromagnetics, RF & Microwave Engineering Version 5.3 3 Replies

Hari Gurumoorthi
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Dear all, I am using a model which has condctors with AC & DC voltage placed at certain distance apart. For AC voltage i am using a sin wave and for DC just voltage. I am using a time dependent solver with a time interaval of 0.001s. The model basically has moving spce charges moving with respect to time. When i start the simulation after a few seconds the models stops (basically the convergence value reaches to a high value). Would be really great if someone could give some suggestions for this problem Thank you so much,

With regards Hari

3 Replies Last Post 09.06.2019, 07:56 GMT-4
Gustavo Leal
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Posted: 6 years ago 04.06.2019, 06:27 GMT-4

Without further information, there is limited help one can offer...

Are you ramping up the values from 0?

Without further information, there is limited help one can offer... Are you ramping up the values from 0?
Alexis Prel
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Posted: 6 years ago 06.06.2019, 08:07 GMT-4

Hi Hari,

Do you really need to solve the AC using a transient solver?

If the AC component is small enough, it can be treated as a linear pertubation of your DC working conditions. This linearizes all your equations and you can then solve the AC equations in a single iteration, provided that you have access to the DC solution.

Again, this is only valid if the AC currents are small enough.

Hi Hari, Do you really need to solve the AC using a transient solver? If the AC component is small enough, it can be treated as a linear pertubation of your DC working conditions. This linearizes all your equations and you can then solve the AC equations in a single iteration, provided that you have access to the DC solution. Again, this is only valid if the AC currents are small enough.
Hari Gurumoorthi
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Posted: 6 years ago 09.06.2019, 07:56 GMT-4
Updated: 6 years ago 09.06.2019, 07:56 GMT-4

Hi Hari,

Do you really need to solve the AC using a transient solver?

If the AC component is small enough, it can be treated as a linear pertubation of your DC working conditions. This linearizes all your equations and you can then solve the AC equations in a single iteration, provided that you have access to the DC solution.

Again, this is only valid if the AC currents are small enough.

Hello Prel, Thank you for your reply, in my case i have 3 conductors with a sine wave AC voltage, and just near to that i have two DC conductors (+ive & -ive). i also have some charges (+ive & -ive) coming out of this DC conductor (they are time depenedent). So, my aim here is to check what was the contribution to the oveall electric field by those charges (asuming that AC will not emit any charges) . I am using an electrostatic which solves the poissons equation (with an input voltage and charges), for charges to move i am using continuty some equations (PDE form). DC works completely fine but when i cput AC conductors the simulations increases the convergence value. Also i am not giving any current inputs to both DC and AC conductors. its just voltgae and charges (in nC). Thank you in advance. with regards Hari

>Hi Hari, > >Do you really need to solve the AC using a transient solver? > >If the AC component is small enough, it can be treated as a linear pertubation of your DC working conditions. This linearizes all your equations and you can then solve the AC equations in a single iteration, provided that you have access to the DC solution. > >Again, this is only valid if the AC currents are small enough. Hello Prel, Thank you for your reply, in my case i have 3 conductors with a sine wave AC voltage, and just near to that i have two DC conductors (+ive & -ive). i also have some charges (+ive & -ive) coming out of this DC conductor (they are time depenedent). So, my aim here is to check what was the contribution to the oveall electric field by those charges (asuming that AC will not emit any charges) . I am using an electrostatic which solves the poissons equation (with an input voltage and charges), for charges to move i am using continuty some equations (PDE form). DC works completely fine but when i cput AC conductors the simulations increases the convergence value. Also i am not giving any current inputs to both DC and AC conductors. its just voltgae and charges (in nC). Thank you in advance. with regards Hari

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