Flexible Reconfiguration Strategy for Novel Advanced Traction Power Supply Equipment Under Fault Conditions

The novel advanced traction power supply equipment (NATPSE), incorporating a two-phase input to single-phase (2AC-AC) conversion unit, provides an effective solution to eliminate neutral sections and improve power quality in electric railways. However, the high integration of active components in this 2AC-AC conversion unit is regarded as the cause of higher fault probability, resulting in insufficient power supply, negative-sequence currents, and even system instability. To address these limitations, a flexible reconfiguration strategy for NATPSE is proposed. Through coordinated control of the controllable switches and the healthy port of the 2AC-AC conversion unit, islanded operation and power supply path reconfiguration of the faulted traction station are achieved. As a result, a 100%-rated power supply is maintained, and 100% suppression of negative-sequence currents is realized. Moreover, power supply is maintained within 0.2 s after port fault occurrence, without adversely affecting the traction load. Finally, the effectiveness of the proposed strategy is verified by simulation and experiments.