Emergency Control Strategy of Hybrid Advanced Traction Power Supply System Based on Multidevice Collaboration

The various hybrid advanced traction power supply systems (HATPSSs) received significant attention due to their high equipment utilization and low reconstruction cost. They mainly consist of a traction transformer and a “two-phase input port to single-phase output port” (2ac–ac) converter. However, as a multiport device with complex fault characteristics, the 2ac–ac converter may cause a negative sequence current, insufficient power supply, and even system instability when any port fails. Additionally, if the traditional redundant backup schemes are applied to HATPSS, the significant extra cost will be exacerbated. To improve the reliability and reduce the cost of HATPSS, an emergency control strategy is proposed by fully using the healthy ports of the 2ac–ac converter, traction transformer, tie switch, and healthy traction station. Then, the rated power operation and negative sequence current suppression on different fault types are ensured by designing reasonable action mechanisms. Finally, the simulation and experiment results are given to verify the feasibility and effectiveness of the proposed emergency control strategy in different fault types.