Power Flow Calculation and Conductor Temperature Change Process Analysis of Single-Line Direct Supply Traction Network

The accuracy of the power flow calculation results of a traction network is closely related to the impedance parameters of the transmission wires of the network, and such parameters change dynamically under the influence of current and geographical and climatic conditions. To make the selection of transmission wires model and the calculation results of power flow highly accurate and congruent with the reality, the theory of electro-thermal coupling is introduced into the calculation of power flow in the traction network, and a power flow calculation method considering the influence of electro-thermal coupling is proposed in this paper. Firstly, the electro-thermal coupling principle of the traction network transmission line is analysed. Secondly, with a single-line direct power supply traction network as an example, the power flow calculation method and realisation process are introduced in detail in consideration of the influence of electro-thermal coupling. Thirdly, the universality of the power flow calculation method is investigated. Lastly, the degree of influence of current and geographical and climatic conditions on the resistance of transmission wires in the traction network and the results of power flow calculations are analysed in the form of examples. Results show that the resistance and maximum allowable continuous current carrying capacity of the traction network are greatly affected by geographical and climatic conditions. The change in transmission wire resistance should be considered in the process of power flow calculation of traction networks.