Research on Reliability Allocation Method for Traction Power Supply System of Electrified Railways in Mountainous Areas

The electrified railways in mountainous areas are faced with multiple difficulties such as weak power grids, special climatic environments, complex and dangerous geographical conditions, which poses a great challenge to the reliable power supply of the traction power supply system (TPSS). In order to ensure that the overall reliability level of the TPSS meets the design requirements, this paper proposes a reliability allocation method for the TPSS of electrified railways in mountainous areas. Firstly, based on the characteristics of the interconnected power supply system of traction substation group (TSG) of the electrified railways in mountainous areas, the special topology of the TPSS, as well as the logical relationships between each power supply area and each equipment are sorted out. Secondly, the reliability allocation model of the interconnected power supply system of the TSG is established, and the reliability index of the system is allocated layer-by-layer from the whole system to the TSG according to the design requirements of the overall reliability level of the system. Finally, the reliability allocation model of the traction substation is established, and the reliability index is allocated to the underlying equipment of the traction substation, so as to clarify the reliability requirements of each power supply area and equipment. The results indicate that the reliability allocation results calculated by the proposed method can assist designers to be informed of the reliability objectives of each subsystem and power supply equipment, and can provide insights for related reliability design.