Topology and control strategy of a novel APF based traction supply system

A novel power supply system for railway traction is present, in which an active power filter is utilized to counteract the quality deteriorating in the three phase power distribution system caused by the single-phase traction system. The proposed system adopts a uniphase topology, which enables all the trains run on the same phase along its whole journey, whereas, at every point where the two system are connected, the single-phase load acts as a symmetrical pure resistance of the three-phase system. Configuration and analysis of the system, a frequency-limited hysteresis current control strategy, and software simulation results that can prove the system´s feasibility are included.