@freeze2056,
this would be something to ask the engineer/architect for this plant
Electricians rarely develop a build plan for similar things, the engineer develops this and the electrical installs and puts in what is needed to make operational. I do however know of some transformers in panels that General Electric and Square D make that are top notch, you could contact them and see what they got first. you also need to explain further cause I haven't seen any large transformers without other components like regulators, protection, and controls. maybe be specific in what this will power.. sounds like motors
also anything manufactured should have schematics you can pull up online