Predictive maintenance strategy of variable period of power rransformer based on reliability and cost

The maintenance strategy of identical period can decrease the reliability of power transformer with the increase of the maintenance times, and a predictive maintenance strategy of variable period of power transformer was presented considering low cost and high reliability. An evolutive model of fault rate , which life decreaseing factor and fault increasing factor were weighted to act as, was constructed. The cost model was built which the costs included small repairing cost, predictive maintenance cost and productive loss. And then an optimal model of predictive maintenance strategy was built bo overcome the shortcoming of predictive maintenance model with identical period which is not operational. Simulation that the distribution of fault time satisfy Weilbull distribution is carried out, and results show that the model is effective.