Decision on maintenance period for power transformer based on Monte Carlo simulation of reliability

The problem of selecting a suitable maintenance period is vital for preventive maintenance of power transformer. Traditionally, maintenance period can be calculated by model with an objective function, such as availability, maintenance cost, or reliability of the equipment. However, it is difficult to directly apply these models for power transformer, because its reliability is high, and there is no enough reliability data to calculate the objective functions. Therefore, a simulated maintenance period model is developed in this paper. Firstly, Monte Carlo method and Fault Tree method are applied to generate simulated fault times of the transformer system. Secondly, Mission Reliability is calculated based on these simulated data and acts as the objective function in the model. Finally, this model is applied to investigate the maintenance period of power transformer.