Research on Control Strategy of Co-phase Traction Power Supply System Integrated with Hybrid Energy Storage System

In order to manage the negative sequence and coordinate the utilization of regenerative braking energy, a co-phase traction power supply system with integrated hybrid energy storage and its hierarchical coordination control strategy are proposed in this paper. Firstly, the topology of co-phase traction power supply system with integrated hybrid energy storage is constructed, in which the power flow controller compensates the negative sequence current and the hybrid energy storage system further realizes the regenerative braking energy utilization and peak clipping and valley filling reduction of the traction load. Secondly, a hierarchical coordination control strategy is established based on this structure. In the upper level control layer, the energy management model is established with the objective of minimizing the daily electricity charge in the traction substation, and the constraint of negative sequence, and the reference power command for hybrid energy storage system and co-phase traction power supply system are generated. The lower level control layer designs the control strategy for each converter in response to power commands from the upper level control layer. Finally, the arithmetic analysis and simulation experiments are conducted through the measured data, the results show that the control strategy proposed reduces the electricity charge by 20.13%.