Study and filtering of harmonics in a DC electrified railway system

The railways are used to transport people, but also for the industry. In this article we present a simulation of real DC traction power supply that intended to transport the natural resources (iron, ore and phosphate) from its source to the industrial areas. We made a model in Matlab/Simulink of a DC traction substation which is located in the mineral line Tebessa - Annaba (in Algeria). Our study focused on the propagation of harmonic currents in the electric network and their filtering solution. The simulations results obtained in this paper for standard operation conditions are presented shows that a value of total harmonic distortion (THD) current exceeds the standards (IEEE 512-1992). In this paper, we present the most effective solution, most used and least expensive to mitigate harmonic currents is the passive filtering, using filters (tuned at frequencies 11 and 13) at two different locations compared to the transformer which supplies the traction substation. In the end we compare the results obtained by determining the THD in each location.