Effect of The DC Traction Substations No-Load Voltage Set Up Over The System Efficiency

The DC traction networks are widely used for urban transportation and short distances. The DC substations transfer the power between the main AC grid and the DC network. The open circuit voltage of the DC substation may be fixed based on the tap changer configuration of the transformer or using a dynamic control over the AC/DC converter. This article studies the effects of the selection of this voltage over the network performance which can be represented by the overall energy efficiency of the system. The simulation models are simplified to speed up the solver under the consideration of the required accuracy. The Aggregated data are used to reduce the storage requirements to save the results of all simulations. This study represents a systematic procedure for selecting the substation voltage to reduce the total losses of the system. The results of the testing on a real case demonstrates the improvement in the overall energy efficiency and the reduction of the total losses.