Modeling of Aging Transformer Failure Rate and the Retirement Timing Decision

Abstract

When making an updating strategy for aging transformer, both the condition of transformer and the risk effect of its aging on power system needed to be taken into account. Based on the model of aging transformer failure rate by insulation age, a comparative analysis of the risk caused by aging failure within the planned period and the profit from delaying updating was undertaken; then the optimal timing strategy to retire transformer was developed on the basis of a balance between risk and profit. The analysis of examples indicated that the proposed process of the strategy could be applied to plan the retiring time according to both the actual condition of transformer and the impact of the risk to the grid, thus making full use of transformer and allowing the power company to get the maximum benefit.