Collaboration and Control Strategy for Dual Traction Station Flexible AC Traction Power System during Catenary Faults

In the flexible AC traction power supply system (FTPSS), a certain short-circuit current is necessary for fault detection following a catenary fault. However, the static power converters (SPCs) have limited current overload capacity. To enable fault detection and rapid system recovery, SPCs must switch from voltage-frequency control (VFC) to fault current control (FCC). This mode switching process can cause issues such as transient voltage and synchronization problems during the soft start of SPCs, leading to abnormal mode transitions. To address these challenges, this paper proposes a communication-based collaboration and control strategy to suppress transient voltage and achieve synchronous soft start. Firstly, the paper identifies the transient voltage and synchronization issues under the continuous operation strategy of dual traction station FTPSS. Subsequently, a collaborative control strategy is introduced. Finally, simulation modeling is conducted on the PSCAD/EMTDC platform to validate the proposed strategy. The simulation results demonstrate that the strategy effectively suppresses transient voltage and achieves synchronous soft start, ensuring correct mode switching.