Research on condition-based maintenance strategy of protection systems based on multistage fuzzy comprehensive evaluation

As the development of power grid in the new period, the disadvantages of traditional maintenance pattern of relays were increasingly prominent. Condition-based maintenance has become an inevitable trend of maintenance system reform. Firstly, after analyzing the operation characteristics and the running state data of protection systems, especially the guard interval is taken as a unit and the states of protection device and the secondary loop are taken into consideration respectively, an integrated state index system of protection system is proposed in the paper. Then the state evaluation model of protection system based on multistage fuzzy comprehensive evaluation is built. By the model, raw data could be analyzed, the state could be evaluated and the state maintenance strategy could be given as the output of the model. The state assessments of protection systems, devices and secondary loops are integrated in the paper. It is helpful to reduce the workload and improve the efficiency. Moreover the state of relays could be evaluated effectively. The maintenance suggestions are presented finally. It is of great significance to the realization of condition-based maintenance of protection systems.