Managing Aged Transformers: Utility develops repair/refurbish/replace strategy using innovative risk-based methodologies

摘要

Utilities are increasingly operating transformers up to and beyond their expected life spans. Asset managers are diagnosing and monitoring the condition of critical and problematic units, and then ranking the transformers by condition to deal in the near-term with the units that affect utility operations the most. However, from regulatory and business planning perspectives, a longer-term view on operating and capital investment is necessary. Developing a repair/refurbish/replace management strategy for significantly aged populations with a rational basis for the strategy is a critical need. This type of strategy requires that asset managers relate the effect of available options on projected failure/replacement rates and their associated costs and impacts. In response to this need, utilities have adopted the assumption that failure/ replacement rates experienced in the past will continue in the future. If utilities had a constant distribution of transformer ages, and if the age distribution was in the flat portion of the "bathtub curve," this would be a valid approach.