Research on Control Strategy of Four Quadrant Converter in Urban Rail Bidirectional Substation

In urban rail traction substation, the high-power four quadrant converter can be used to replace the existing 24 pulse rectifier. The four quadrant converter can realize bidirectional flow of energy, provide traction energy when the train is in traction state, and feed the energy back to the AC power grid when the train is braking, so as to achieve the purpose of energy saving. In this paper, a 2MW prototype is designed, and the main circuit topology and parameters are given. When LCL filter is used, two control strategies, passive damping and active damping, are studied, and their effectiveness is verified by Matlab/Simulink. The multiple topology and the corresponding droop control strategy are also given. At last, a 2MW high-power prototype is built, and some experiments have been carried out.