Value Evaluation Based Maintenance Decision Methods For Railway Vacuum Circuit Breakers

By the end of 2021,there were 377 traction substation booths within the jurisdiction,and the number of vacuum circuit breakers in traction substations reached2,564.Vacuum circuit breakers are crucial for supplying power to overhead contact lines in the railway traction power supply system.Therefore,making reasonable maintenance decisions is an important task for the railway power supply system.However,it is a complicated problem that involves not only the equipment condition but also the overall operational risk during maintenance.To address the problem of formulating maintenance strategies for railway 27.5kV vacuum circuit breakers according to their operating states when making annual maintenance plans,this study aims to construct a maintenance value model and a maintenance decision-making process for 27.5kV vacuum circuit breakers under different states.Based on the state evaluation method,state transition probability,maintenance cost analysis,and maintenance value evaluation of the vacuum circuit breaker,a fuzzy state evaluation scoring strategy model of the vacuum circuit breaker was proposed.This model can refine the overall state evaluation of the vacuum circuit breaker and reduce the score deviation compared to the existing regulations,to avoid over-maintenance.At the same time,a maintenance value evaluation index based on the five-state Markov model was designed.By considering the maintenance costs and equipment status changes before and after maintenance comprehensively,the maintenance value evaluation of individual equipment was calculated and prioritized,and the annual optimal maintenance strategy of the vacuum circuit breaker was generated.The proposed method considers the two factors of the equipments own value and running state when evaluating the maintenance value of vacuum circuit breakers under different maintenance strategies.This helps operation and maintenance units to optimize maintenance strategies continuously.The feasibility,practicability,and effectiveness of the proposed method are verified by experiments.