Maintenance decision making of power transformer by integrated considering reliability and economy

Reliability and economy of power transformers are not reasonably considered in the condition based maintenance problem recently. Towards this problem, a model considering reliability and economy is established to select the best maintenance strategy of a transformer. With the corrected parameters, a condition assessment model including DGA test, oil test and electrical test is applied to decide the health index of the transformer. After building the relationship between the fault ratio and the health index, a minimum optimization model including the financial loss risk of the transformer is established to simulate the maintenance effect. A particle swarm optimization method is developed to choose the best maintenance strategy of the transformer. A case is studied and the result demonstrates that the proposed method is reasonable and it offers a new thinking to the risk based maintenance.