Electrified railroad through power supply system without split phase

The invention discloses an electrified railroad through power supply system without split phase. The electrified railroad through power supply system is characterized in that a traction transformer in a traction substation is a three-phase-two-phase balancing transformer, the three phases of the primary side of the three-phase-two-phase balancing transformer of each traction transformer are correspondingly connected with the three phases of the same public power grid, a power flow controller is connected between the two output phases of the three-phase-two-phase balancing transformer, and one of the two output phases supplies power to a locomotive; each traction transformer uses the same phase to supply power to the locomotive; and the power flow controller consists of a first single-phase isolating transformer, a first voltage source inverter, a direct-current coupling capacitor, a second voltage source inverter and a second single-phase isolating transformer which are connected in turn. The system can implement railroad full-line connection in the same power supply network, and has no split phase through power supply so as to simplify the engineering design and save the investment and maintenance expense; and the system ensures the high-speed, stable and safe operation of the train, and is particularly suitable for high-speed and heavy haul railways.