AC losses in transformers

[Sofia Nunez]

Dear PVsyst, 

Our team has been running two different different ways to calculate the MV transfo losses. 

1. One assuming as a whole system, 4 MV transformers
2. Second, by block, means that for each block, we have its corresponding MV transformer that in total are 4 MV transformer

The problem and I don't understand why is that the losses between both versions are huge as you can see below. 

Could you explain me why it is such a big difference?

Thanks

 

 

[André Mermoud]

I observe that on the left, you have defined an iron loss fraction of 0.06%, which is reasonable (the usual values are around 0.1% of the nominal power).

On the right, you have defined 0.77%, which is extremely high.