Research on Optimal Nonperiodic Inspection Strategy for Traction Power Supply Equipment of Urban Rail Transit Considering the Influence of Traction Impact Load

The inspection and maintenance work of traction power supply equipment (TPSE) is growing heavy with the construction and operation of a large number of urban rail transits (URTs). In order to improve the existing regular preventive maintenance mode and implement a “high-efficiency with low-cost” maintenance strategy, this article proposes an optimal nonperiodic inspection decision-making method for TPSE of URT considering the influence of impact load. First, the comprehensive degradation model of TPSE is established based on the linear Wiener process and the compound Poisson process. Second, the nonperiodic inspection model of TPSE in a single-maintenance period is established by introducing inspection planning functions for three types of degradation processes. With the lowest operating cost per unit time as the decision goal, the optimal maintenance plan is, thus, achieved. Finally, the proposed decision-making method is applied to the benchmark data taken from a URT administration in China related to a dry-type traction transformer in five years. The results show that the proposed method can help formulate efficient inspection strategies with the optimal cost. In addition, sensitivity analysis reflects the influence of different parameters on the optimization results, which helps to identify which parameter exerts the largest influence.