Transformer maintenance decision-making model based on largest annual average profit considering repair effect

Power transformer in grid is one of the most important electrical equipment, the core of energy conversion and transmission. We can promote the economic benefit of power transformer remarkably by arranging for maintenance in time after one or more indicators show transformer is going to fail or its performance is deteriorating. This paper holds a further discussion on repair effects, introduces adjustment factor into the determination of the benchmark aging curve, and describes the repair effects and its corresponding extend maintenance time more accurately by comparing the actual aging curve with the benchmark aging curve. Then, based on the repair effects, this paper constructs the maintenance decision-making model in which the largest annual average profit is reached, and provides the method with which the optimum overhaul moment and the next decision-making moment are determined. Taking the failure rate of power transformers into consideration, this paper also provides the maintenance manager with quantitative evidence while making decisions in term of economy. In the end, a case is used to verify the validity of the model and method presented in the paper.