Research on coordinated control strategy of multi-port railway power conditioner with integrated PV-storage

The Railway Power Conditioner (RPC) takes the traction power supply system as a whole and compensates the load on the adjacent two adjacent power supply arms in negative sequence and reactive power respectively, so as to effectively reduce the impact of the traction load on the public power grid. However, the traction load has the characteristics of large peak-to-valley difference and frequent state switching, and the DC impedance will have negative impedance characteristics in the process of two-way transmission of RPC power, which will affect the accuracy of RPC power compensation, cause the fluctuation of RPC DC bus voltage, and affect the effect of negative sequence current treatment on the power grid side. Therefore, this paper proposes a coordinated control method for multi-port railway power conditioner with integrated photovoltaic energy storage, theoretically analyzes the power quality compensation mechanism of RPC and the power transmission relationship between each port of the three-port converter, and proposes a coordinated control strategy for various typical operating conditions of traction load state switching and optical storage system, which improves the stability and dynamic performance of DC voltage under the bidirectional flow of RPC power, and improves the effect of negative sequence current management on the grid side. Finally, the experimental results verify the effectiveness and accuracy of the coordinated control strategy.