Research on reliability analysis of high-speed railway traction substation system under common cause failures

The reliability of the system is influenced by the common cause failure mode and the multi-state characteristic. This paper proposes an improved multi-state multi-value decision diagram method to analyze the reliability of high-speed railway traction substation systems. According to the requirements of safety-critical system reliability analysis, this paper begins with an analysis of the system structure and unit module status, comprehensively considering the influence of common cause failures and multi-state characteristics. In this paper, we design the principle of transforming the fault tree model into a binary decision diagram model. Fully considering common cause failures, we extend the model to a multi-state multi-value decision diagram and provide a reliability and importance model calculation method based on state probabilities. The results indicate that this method can accurately and efficiently calculate the reliability level of the high-speed railway traction substation system, effectively identifying key components and weak links within the system. By utilizing visual models, the mechanism of common cause failure in multi-state system can be explored.