A Notch Filter-Based Active Damping Control Method for Low-Frequency Oscillation Suppression in Train–Network Interaction Systems

Low-frequency oscillation (LFO) in the train- network interaction system would easily lead to traction blockades and seriously threaten the normal operations of high-speed railway systems. This paper proposes a notch filter-based active damping (NFAD) control method to suppress the LFO. First, a small-signal model of the train-network interaction system is developed to investigate the LFO mechanism. By sensing and feeding back the input current of four-quadrant converter, NFAD control method is then formulated to emulate a virtual resistance in order to increase the system damping. Furthermore, a fundamental notch filter is designed to mitigate the damping influence of virtual resistance on the fundamental component. Finally, simulation and experimental results are employed to demonstrate reliability and effectiveness of the proposed method.