Research on Control Strategy of Flexible AC Traction Power Supply System Substation

The flexible AC traction power supply system can solve the power quality problem and realize flexible power supply of the whole line, which is an important direction of railway development. First, this paper introduces a flexible AC traction substation based on three-phase to single-phase MMC structure, which provides stable voltage support for train operation. Then, the influence of the filter capacitor on the output side is analyzed, and a damping control strategy for substation is designed to suppress potential oscillations. Aiming at the problem that the voltage amplitude and frequency deviate from the rated value in the traditional droop control, a droop control strategy with voltage amplitude and frequency recovery without communication for substation is designed, and the feasibility and effectiveness of the control strategy are verified by simulation.