Generator Step-Up sizing 1

[Power0020]

I wonder if there is any IEC or IEEE standard recommendations for GSU sizing criteria?

I have seen different utilities with different criteria like matching the ONAN rating with the Gen. capability, others match the ONAF rating (this leads to capital saving however, failure of Transformer fans will lead to lower power flow!)

any clue?

 

[prc]

IEEE Std C57.116-2014 Transformers connected to Generators