[FEATURE] Loading output across the windings of a three-winding transformer (relative loading of the branch)

[WinApiMan]

Hi! When calculating the network, a question arose about determining the load of a three-winding transformer.
If I understand the calculation correctly, you select the most heavily loaded branch and display the result. Is it possible to display the load for all three branches? This would provide a more accurate picture of the transformer's load.

[mgovers]

Hi @WinApiMan,

We discussed this briefly within the team and we are OK with the addition. Our proposal is to do the following:

• Keep the existing loading attribute the way it is
  • This ensures backwards compatibility
• Add 3 new attributes:
  • loading_1, loading_2, loading_3
  • This aligns with the conventions regarding the rated power (sn_1, sn_2, sn_3, resp.)
• The per-branch version loading_* will be s_1 / sn_1, s_2 / sn_2 and s_3 / sn_3, resp. in the calculation of the loading, while the loading attribute will be the maximum of the individual per-branch loadings.

We did consider the added output data overhead, but given the fact that there are typically fairly few three-winding transformers in the grid, the added overhead should be small. If users are in fact concerned with data overhead, they can always opt-out by switching to columnar data, and selecting the specific columns for which they want to get the output.

[mgovers]

BTW: I added the good-first-issue tag because I believe it's something that is relatively easy to add and an easy thing to be introduced into the core implementation of the power-grid-model. If you want to, you can have a shot and we can give you some pointers in the right direction.

[WinApiMan]

Hi @mgovers! Thanks for the answer! At the moment we have solved this problem by calculating the load on the branches ourselves. But since we have to group the input and output json for calculation, it should take less time on your side.

[kornerc]

@mgovers I could try to solve this issue

[figueroa1395]

Hello @kornerc! We are very happy to hear this. I will then assign this issue to you. Do give it a try and ping us if needed, we'll provide any necessary or requested assistance.

Looking forward to the PR!

[figueroa1395]

One more thing @kornerc. Even though you haven't asked, I thought about pointing you towards #729, where we made an extensive list of things that need to happen when adding new components. It may come in handy when adding these attributes, and you can use it to guide yourself, as there are many things that can be easily missed.

[kornerc]

Thank you @figueroa1395 for referencing #729.
This is a helpful starting point for me!