hysterisis

[giirakok]

I need to simulate a nonlinear transformer such as this one

I have been looking at ways to model my own nonlinear transformer but don't really know how to do that and ther are a lot parameters...would really appreciate some help

[Tayyab_R]

Hi giirakok,

You can use the virtual transformers provided in the component database to setup the parameters in the way you would like. You can right-click and select Place Component. In the Select a Component window, select Database: Master Database and Group: Basic and the Family: RATED_VIRTUAL. There you will see two virtual transformer models TRANSFORMER_CT_RATED and TRANSFORMER_RATED. You can use the one which suites your needs.

Hope this helps.

[giirakok]

Thank you Tayyab,

I am using that information, but I also ran into trouble when I was trying to making an equivalent subcircuit for an transformer. I could not find current/voltage controlled opamps like in the picture below in the middle. Where do I find those in multisim or how can I make them if they are not there?

thank you so much for your help, I am just learning multisim so excuse me if appear clueless (I am stumped!)

[Tayyab_R]

Hi giirakok,

What you should do is look for the specific part number of the component which you would like to use in your circuit. After selecting a specific component, you can search in the database for the component. If the component is not available in the database, you can get the pspice or spice model for the component from the manufacturer's website and create a custom component which suites your needs. The following link is a tutorial for how to create custom components in Multisim 

https://decibel.ni.com/content/groups/circuit/blog/2011/04/06/component-creation-101

Hope this helps.

[OStep]

The triangular looking elements in your screenshot are basic controlled sources. You can find equivalent components in the Multisim database under the CONTROLLED_VOLTAGE_SOURCES and CONTROLLED_CURRENT_SOURCES families.

However, I am confused about what your actual goal is. Is it to model and study the hysterisis effect? or is it to get an adequate model of a transformer so that you can build a circuit with?

So, what exactly are you trying to achieve?

[OStep]

if you do in fact need a non-linear core, what input data do you have to parameterize it:

Inductance vs current?

Flux linkage vs current?

B-H curve or specification of the core material along with and the transformer geometry?

[giirakok]

Hi Max,

my goal is to get an adequete model of a transformer that is nonlinear. I was trying to do it with those controlled sources because the whole circuit is an equivalent circuit for a transformer that you can then pass subcircuit parameters to. It is the right B-H that I am after,assentially a transformer that goes into saturation and therefore would exibit hysterisis loss. 

Thank you for your help.