<p>Conventional DC power traction systems often rely on transformers with fixed tap winding ratios, leading to passive energy supply and limited opportunities for efficiency improvements. This paper introduces a new, active control approach that uses an Electronic On-Load Tap Changer to dynamically adjust the substation’s output voltage. The proposed Active Multi-Reference Voltage Control method actively regulates voltage thresholds based on real-time train movement and power conditions. This strategy maximizes the use of regenerative energy and minimizes overall system energy loss. Field measurements and simulations using PSCAD software confirm the effectiveness of this method. The simulation results show that implementing active control can increase the voltage to reduce line losses by up to 5.46%. Conversely, lowering the voltage increases the utilization rate of regenerative energy by as much as 21.54%, which in turn decreases the amount of energy wasted as heat in the train vehicles. These findings demonstrate significant gains in energy efficiency with minimal changes to existing infrastructure, highlighting the practical benefits and economic viability of integrating control into DC railway traction systems.</p>