Yes, its a valid question. Problem is no avionics engineer is responding to it here..
But I can somewhat give you a lead (or two)
AC systems have 3 wires, live, neutral and ground.
DC have 2.. as you know it. Now are the GROUND still the same?
Another clue. The aircraft's AC generator has a 3 phase output. How many wires?
That should answer your question.
