Failure Risk Interval Estimation of Traction Power Supply Equipment Considering the Impact of Multiple Factors

Quantifying the failure risk of traction power supply equipment (TPSE) is of significant importance to the safe and stable operation of the traction power supply system. This paper proposes a method for conducting failure risk interval estimation for the TPSE while accounting for the impact of multiple factors. This method consists of two parts, i.e., the estimation of failure probability interval, and the analysis and quantification of the failure consequences: 1) based on the historical statistical data of equipment failure, a credal network model of TPSE is constructed. By combining the imprecise Dirichlet model and the inference algorithm of credal network, the probability interval of equipment failure is estimated for a given operational condition and 2) the risk-based failure mode and effects analysis table is established for qualitatively analyzing the failure risk of TPSE. This, coupled with the consideration of equipment failure level, enables the quantification of failure consequences from the perspectives of both economic loss and time loss. Finally, the estimation of equipment's failure risk interval is obtained by integrating the failure probability interval and the quantitative consequences. A case study is conducted utilizing the failure samples of contact mesh equipment derived from the practical power supply section, so as to verify the validity and usability of the proposed risk interval estimation method and the corresponding indices.