A Two-Stage Framework for Power Transformer Asset Maintenance Management-Part II: Validation Results

A two-stage framework for transformer maintenance management is introduced and formulated in Part I of this two-part paper in the context of transmission asset management strategies (TAMS). The proposed model optimizes maintenance outage schedule over a predefined period of time by taking into account the actual and expected transformer assets' condition dynamics in terms of failure rate and resource limitations in midterm horizons, as well as operating constraints, economic considerations and N-1 reliability in the shorter term. In Part II, a small six-bus system is first used to demonstrate how the two-stage maintenance framework works using a step-by-step procedure. Then, IEEE-RTS is used to investigate the performance of the proposed model in more detail. In addition, the impacts of varying the characteristics of the proposed midterm and short-term maintenance schedulers, such as flexibility in time horizon selection, on maintenance scheduling results and computational efficiency are investigated on IEEE-RTS. The numerical studies indicate that the proposed framework gives appropriate results in terms of economics and technical constraints at a reasonable computational cost.