Flux Simulation Formula

Andoni Garcia
Andoni Garcia Altair Community Member
edited October 2020 in Community Q&A

I'm doing the final degree project using FLUX (I'm new here) and I would be so grateful for some help.

 

What I have to do is firstly simulate the electromagnetic behaviour and losses of a specific transformer core at some frecuencies (50 Hz, 1kHz), just for make a comparison of these results with the reality behaviour. If a deviation exists (I see it possible) I would like to search out where it comes from. This is so important due to fact that after this step, I would have to simulate it at higher frecuencies (150kHZ or more) and those simulations would provide a more reliable results. 

 

To summarize, I would like to know how the simulation solver works, wich formula applies to get the results regarding power losses; or where can I get that information.

 

So appreciated, sincerely

Andoni

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Answers

  • Alejandro Rodríguez
    Alejandro Rodríguez
    Altair Employee
    edited June 2019

    Hello Andoni,

    Actually, you have two examples in Flux supervisor about the way to simulate transformer. Within these examples complete documentation and the simulation process explained step by step are also included (image attached).

    Flux Supervisor (3D) -> Open Example ->  Application notes -> Power transformer

    Flux Supervisor (3D) -> Open Example ->  Application notes -> Three phases transformer Overlay

    <?xml version="1.0" encoding="UTF-8"?>image.png

    Additionally, losses in transformer are not an easy matter since there are several different types: losses in the windings (Joule losses), losses in the magnetic core (iron losses) and also many kinds of “parasitic losses”, among them losses caused by induced currents in the tanks are specially relevant.

    Flux is able to calculate all this effect using different approaches:

    -From winding losses: They are Joule losses which are calculated taking advantage of the circuit context contained in Flux. The coupling between FEM simulation and circuit simulation allows to obtain the current density distribution within the coils and, using these values, obtain Joule losses.

    -From magnetic core losses: In the postprocessing options you have the possibility to calculate the iron losses using Berttoti (you should provide the material coefficients needed to use this approach).

    -Losses from induced currents in the tank: Induced currents are calculated during the magnetic simulation if the tank is defined as “magnetic conducting region”. From this currents the Joule losses can be evaluated using a sensor.

    For more information, please consult the supervisor examples I have talked you about.

    Hope this helps.

    Best regards.

  • Andoni Garcia
    Andoni Garcia Altair Community Member
    edited June 2019

    Hello Andoni,

     

     

    Actually, you have two examples in Flux supervisor about the way to simulate transformer. Within these examples complete documentation and the simulation process explained step by step are also included (image attached).

     

     

    Flux Supervisor (3D) -> Open Example ->  Application notes -> Power transformer

     

     

    Flux Supervisor (3D) -> Open Example ->  Application notes -> Three phases transformer Overlay

     

     

     

     

     

    <?xml version="1.0" encoding="UTF-8"?>image.png

    Additionally, losses in transformer are not an easy matter since there are several different types: losses in the windings (Joule losses), losses in the magnetic core (iron losses) and also many kinds of “parasitic losses”, among them losses caused by induced currents in the tanks are specially relevant.

     

     

    Flux is able to calculate all this effect using different approaches:

     

     

    -From winding losses: They are Joule losses which are calculated taking advantage of the circuit context contained in Flux. The coupling between FEM simulation and circuit simulation allows to obtain the current density distribution within the coils and, using these values, obtain Joule losses.

     

     

    -From magnetic core losses: In the postprocessing options you have the possibility to calculate the iron losses using Berttoti (you should provide the material coefficients needed to use this approach).

     

     

    -Losses from induced currents in the tank: Induced currents are calculated during the magnetic simulation if the tank is defined as “magnetic conducting region”. From this currents the Joule losses can be evaluated using a sensor.

     

     

    For more information, please consult the supervisor examples I have talked you about.

     

     

    Hope this helps.

     

     

    Best regards.

     

     

     

    First of all, thanks for your answer Alejandro.

     

    I'd seen those documents and I actually know how to structurate a core with windings. But the reason that I openned this topic, sorry if I didn't have explain correctly, is because I would like to know the algorithm that this program utilize when simulating. I understand that it focuses on every points of the meshing but I want to dig deeply specially in core losses.

     

    Take it into account that I introduce the 6 Bertotti modified parameters (that I get from the spreadseet of Flux's file folders) into the material information for calculating the losses. I also know that there's another way to calculate the Berttotti (NON MODIFIED) losses, is this way more accurated?

     

     

    Thanks for all.

     

  • Alejandro Rodríguez
    Alejandro Rodríguez
    Altair Employee
    edited June 2019

    You are welcome. Sorry but I misunderstood your initial question.

    Please, find attached some technical information explaining the formulas used to calculate iron losses through Berttoti method.

    You have also the possibility to use other estimation methods in order to apply Berttoti, but they are deprecated because of their lesser accuracy.

    Just one remark: losses are calculated taking into account all the nodes in  your mesh and (if you are doing a transient simulation) for every instant of time. However, they are not calculated during the solving process but during the postprocessing. During the solving you are just stocking some variables in all the concerned nodes (i.e., the nodes appertaining to laminated regions) that then will be used to calculate iron losses using Berttoti.

    Best regards.

    Unable to find an attachment - read this blog