I usually have to stick my nose in............we just use 230V. That's it.Just simple. Why, Jrjef, do you need 208, 103, 236, 240V ?
208 and 240 are nominal voltage systems here. Actual no load of such systems can vary but around where I do work it often is about 215 and 250.
104 and 236 are just values that happened to come up in portions of his buck boost diagram.
Correct me if I'm wrong but your 240 is usually just line to neutral voltage of 415/240 wye systems isn't it? So the 240 is mostly only a single phase voltage. Here we commonly have 208/120 wye or 240 volt delta three phase (which may have a 120 volt single phase mid tap on one phase) as well as 480 volt three phase systems which can be delta or wye though wye tends to be most common and with it we often use line to neutral @ 277 for lighting loads.
Why so many utilization voltages? good question. 600 volts is also out there though a majority of that tends to be in Canada from my understanding. Never ran into any services of that rating here. Have seen used equipment that came from Canada that had 600 volt motors on it, we ended up replacing motor with 480 volt motor.