In reading up on my old power systems material, I have some questions (since I no longer have the professor's brain to pick).
For starters, let's say I have a transformer-based power supply/ system. Typically I have been looking at Y-D, Y-Y, D-D, D-Y configurations but I'm not particular about which one. If I hook a load up to a transformer that is rated in a particular way, what happens when the load draws less than the rated amperage, and what happens when it draws more (or attempts to draw more) than the rated amperage? In other words, in my reading, I am starting to see that one has to be very precise about the difference between what a system*can* or *does* provide (i.e. maximum rating) vs. what it actually *does* provide when various loads are hooked up.
Second question, even dumber than the first one: If one "main function" of a transformer is to provide power through the means of two "physically disconnected" conductors (i.e. the coils), what does that buy you vs. just having a pair of conductors from the source? I think I have probably seen the information already that gives me my answer but I need a reminder. In other words, why bother with coils at all? Why not just have the ground and hot lines? (I'm speaking of a 1:1 transformer for the purposes of this argument.)
Third question: When banks of transformers are constructed and arranged at power stations, do they really take on a physical Y or D configuration, i.e. can you actually see them that way, or does their physical arrangement differ from the conceptual arrangement on a drawing?
Forgive me for this but these are the kinds of questions that fall through the cracks in my reading, i.e. I wonder about them now that I'm older and am able to think better about these topics than when I saw them the first time around.