Resilience of a ۱۵۰۰ V DC Metro Traction Power Supply Network under Rectifier Internal Faults: Evidence from Two Case Studies on Shiraz Metro Line ۱

The ability to maintain traction-power delivery after a severe equipment fault is an important operational property of an urban rail system. This paper examines two documented rectifier-related faults on the ۱۵۰۰ V DC traction network of Shiraz Metro Line ۱: an internal fault in rectifier MG۰۱ at Dastgheib traction substation (TSS) in November ۲۰۱۸, and a cable-insulation fault in the DC-filter output circuit of rectifier MG۰۲ at Ghadir TSS. According to the available incident summaries, both events led to operation of the Frame-Fault protection and PLC-mediated tripping of both transformer incomers, resulting in isolation of the affected TSS. Nevertheless, no major interruption to train service was reported, and the overhead contact line (OCL) remained supplied through the surrounding network. The cases are reconstructed using a common event-analysis framework covering the initiating fault, recorded protection response, final substation state, reported service outcome, and remaining supply paths. The evidence indicates that, for these two events, inter-station supply capability—not continued operation of the parallel rectifier within the faulted TSS—was the principal mechanism associated with service continuity. Because emergency equipment ratings, load-sharing measurements, and detailed train-operation records were unavailable, the study makes no quantitative claim about spare capacity or a numerical resilience index.

کلیدواژه ها:

DC traction power ، ۱۵۰۰ V ، metro ، rectifier fault ، Frame-Fault protection ، traction substation ، operational resilience