A scheme is proposed to use a Railway Static Power Conditioner (RPC) to dynamically balance phase-to-phase active power and reduce the overload frequency of traction transformers in response to frequent overload alarms and trips in some substations of the Lanxin Line. Firstly, on-site research on the daily load situation and overload situation of a V/v connection traction substation on the Lanxin Line was conducted in the past two years, using Origin to process the collected data and obtain the distribution patterns of power, voltage, etc., in the substation; Secondly, a control strategy and simulation model for RPC under extreme load current flow in the power supply arm are proposed in MATLAB/Simulink. The response effect and self-characteristics of parallel RPC under different load changes are simulated. Based on the assessment criteria of whether the transformer has experienced overload, simulation results show that after the RPC is put into operation, the three-phase grid side current is balanced, and under the same load conditions, the overload alarm and trip frequency are significantly reduced. The simulation results have verified that the installation of RPC can achieve power balance between phases on the feeder side, effectively improve the three-phase power quality on the grid side, reduce the overload of traction transformers, and improve the utilization rate of existing traction transformers.