What iare the main advantages of Dc power supply transmission over AC transmission?
From what I could glimpse of the answers so far, nobody (edit: except ernie) really has hit on the major advantage of DC transmission, and it appears that some believe that DC is never used (on the contrary, the Pacific Intertie that connects the Pacific Northwest with south California is but one of a few examples worldwide). While you probably already know the various advantages of 3phase AC transmission (usable by transformers, naturally created by generators, etc), the one primary advantage that DC has over AC is the number of conductors (and hence cost to implement). There is a point where the length of a set of AC transmission lines dictates that it would be cheaper to implement under DC using AC/DC conversion and the fewer lines. Other advantages include very little line reactance or skin effect, which both reduce the line impedance. Obviously, the length where DC is more economical than AC is pretty long, otherwise you would see it more often. Max voltage at which DC can be tran
