The optimal maintenance strategy of power transformers based on the life cycle cost

The maintenance strategy has an impact on the life cycle cost of power transformers. There are many problems in existing maintenance models, such as neglecting the influence of the overhaul on the reliability or ignoring the relationship between the failure rate and the equivalent age and so on. In the paper, the concept of a variable weight and a retirement age were introduced based on the life cycle cost, and a graphic method based on the variable weight was proposed. The method considered the weight, the cost, the failure rate and other factors. And from the perspective of the life cycle cost and the failure rate, the method was used to select the optimal maintenance scheme. In the end, the comprehensiveness and the feasibility of the method were proved by cases.