Modeling of direct current traction power system with the consideration for earth conductivity

Nowadays, one of the main tasks facing the JSC Russian Railways is the increase of volumes of freight transportation. The solution of this task is directly connected with the increase of the load on traction power system devices and their strengthening, which is primarily related to railways electrified with direct current that are characterized by high traction currents. In order to assess the possibility to strengthen a railway section and reveal «bottlenecks» in traction power supply system it is necessary to create a mathematical model of traction power system that must consider parameters of a specific section including earth conductivity that affects the values of skin resistance, potential of railway network and stray currents. The paper proposes a mathematical model of direct current traction power system that represents a combination of a catenary model and a model of railway network. The model considers parameters of traction substations, connection scheme of catenary suspensions and possible influence of rails from adjacent tracks on each other.