For one-way connection, the structure is simple,
but its negative sequence component is the largest of
several traction transformer connection types. Single
phase V/V connection corresponding greatly reduces
the negative sequence component. Especially, when
heavy arm load is twice than light arm load, the nega-
tive sequence influence generated by the light arm load
is only half of the heavy arm load. The above analysis,
when the current of two power supply arms equal, neg-
ative sequence current of single phaseV/V transformer
is half of the positive sequence current, and impedance
matching balance transformer is 0. The balance trans-
former can reduce the negative sequence current of
traction station injection system. Actually, it’s almost
impossible