Direct current traction power supply system

The utility model discloses a direct current traction power supply system. The direct current traction power supply system consists of traction substations and a traction network. The traction network consists of a contact network and steel rails. The traction substation SSk comprises a three-phase alternating-current inlet wire breaker QFJk, a traction transformer TTk, a diode rectifier Uk, a direct-current inlet wire disconnector QSZk and a current transformer LHk thereof, a direct-current bus Bk and a voltage transformer YHk thereof, direct-current feeder disconnectors QSZ(k,1) and QSZ(k,2) and current transformers LH(k,1) and LH(k,2) thereof, a direct-current bus protector and a direct-current feeder fault protector. The direct current traction power supply system omits direct-current breakers, reduces investment and is convenient in enforcement and applicable to new cable construction or old cable alteration at places where the cable is not very long.