I am trying to understand space vectors in 3 phase machines. If you have a balanced 3 phase system, the 3 phasors of voltage, current or whatever... should sum to 0. i<0 + i<-120 + i<-240 = 0. But in this image of a rotating space vector : (http://people.ece.umn.edu/users/riaz/animations/spacevecmovie.html) you can see that the 3 voltage phasors do not sum to 0, but they sum to the space vector. I think the space vector (SV) equation is this : ##SV = Acos(wt) + Acos(wt-120)<120 + Acos(wt-240)<240 ## Why do you have those extra <120, <240 ? If the fact that the 3 vectors are out of phase is already represented by their changing magnitude, why are they put at different angles a second time?