When a flexible DC traction power supply system experiences a metallic transient short-circuit fault between the poles of the catenary

the short-circuit overcurrent can reach as high as tens of kA

which can easily cause the bidirectional converter in the traction substation to be blocked or even damaged. Although the existing high current tripping protection can prevent equipment damage

it may result in a prolonged system power supply recovery time. Therefore

this paper proposes a transient fault ride-through method for the flexible DC traction power supply system based on active feeder fault current limiting. First

the operational principle of the flexible DC traction power supply system is introduced

and its fault characteristics are analyzed. Then

an active feeder fault current limiting device is designed

and a corresponding transient fault ride-through method is proposed

along with the design methodology for the current limiting interval and current limiting inductance parameters. Through simulation verification

the results demonstrate that the proposed method can effectively suppress the short-circuit current and prevent the blocking of the bidirectional converter in the traction substation during transient faults

significantly improving the power supply reliability and safety of the flexible DC traction power supply system.